Foundry Trade Journal : with which is incorporated the iron and steel trades journal, Vol. 72, No. 1459

BRITISH MOULDING [m achine C° V?

.FAVERSHAM, K E N T .

WITH WHICH IS INCORPORATED T H E IR O N A N D S T E E L T R A D E S J O U R N A L

V O L . 7 3 . No. 1 4 5 9 . A U G U S T 3 , 1 9 4 4 r s in g le C o p y 6d. B y P o .t R egistered a t th eG.P.O. as a N e w sp ap e r U fltc e s : 4 9, W e llin g to nStreet. S tran d , Lonaon,W .C .2 . L ^ n ^ O v e r s e a ^ l U - ^ P r e p a

Used by many leading foundries

D I S T R I B O N D

Ihe PROVEN B R IT ISH substitute fo r Bentoniti D ISTRICT CH EM ICAL COMPANY LTD.

1 -1 9 , New Oxford S tree t, London, W.C.1

BfackSàcuH Ptehßßtid

MANSFIELD MOULDING SANC

• P U L V E R IS E D R E A D Y F O R U S E I F R E Q U I R E '

ALBION (Mansfield) SAND CO.

?HO Ps : W A R » A ' 6 * ® " W « * ‘ . S H E F F IE L I T e le p h o n e s: S h e ffie ld 26311 (1 5 lines) M ansfield 37

m

CO KE T I R E D

TYPE B.S.3 TILTEI

440 lbs. G U N M E T A l.

M E L T E D 40 M I N S . P O U R IN G T E M P .

1,300° C.

r È J f

MIDLAND MONOLITHIC

BLACK SEAM HOUSE • NARBOROUGH-LtlCESTER

TELEPHO NES 2 2 2 8 - 9 NARBOROUOH ( LEICS.) 2 LINES T E L E G R A M S M O N O L IT H IC - N A R B O R O U O H -LEICESTER

SAND TESTING

;nd f n r C a ta lo g u e o f Testing M a c h in e s to

IS N O W V ITAL TO ALL FOUNDERS TO EC O N O M ISE SAND A N D M A K E BETTER

PRICE'S FIREBRICKS

IN C S

A S U S E D B Y T H E L E A D I N G I R O N A N D S T E E L W O R K A N D F O U N D R I E S A T H O M E A N D A B R O A D . . . .

M a n u fa c tu re d b y S e n d u * y o u r E n q u i r it

J. T. PRICE & CO. LTD., STOURBRIDGI

2 F O U N D R Y TRAD E JO U R N A L A U G U S T 3, 1944

F O U N D R Y

B L A C K I N G S

FOR IRON & ST E E L F O U N D E R S

C O A L D U S T C H A R C O A L , P L U M B A G O B L A C K L E A D , CORE GUMS, “ C O R El T E ,”

L I Q U I D C O R E B I N D E R A N D A L L F O U N D R Y R E Q U I S I T E S

I S A A C & I S R A E L W A L K E R

EFFING HA M MILLS, R O TH ER H A M

C O N T R A C T O R S T O THE W A R OFFICE A N D A D M IR A L T Y Telephone : R O TH ER H A M , N o . 33. Telegram s : “ W A LK E R S ,” R O T H E R H A M

ESTABLISHED 1831

★

P L U M B A G O F ACI NGS

O u r Spécialité is Studying Special R equirem ents K i n d l y h a n d us y o u r

e n q uirie s

C A M B O R N E , , , E N G L A N D

’P h o n e : ’ G r a m s •

C a m b o r n e 2275 A i r d n l l , C a m b o r n e L o n d o n O f f i c e : B r o a d S t r e e t H o u s e E C !

PNEUMATIC PLANT SPECIALISTS

?ARD ITTING U m m ers

Q

AUGUST 3, 1944 r o J N D R Y TRADE JO U R N A L

"LITTLE COURT'! PYRFORD COMMON, W O K IN G , S U R R E Y .

Telephone:-BY FLEET 3 1 0 0 Telegrams:-"lRONOBRIT,PHONE,WOKING.'’

The fa c t th a t goods made o f raw m a te ria ls In short supply owing to w a r conditions are advertised in th is paper should not be taken as an in d ic a tio n th a t th$y ore necessarily ava ilable fo r export

4 F O U N D R Y TRAD E JO U R N A L AUGUST 3, 1944

B r i t i s h M o u l d i n g M a c h i n e C ^o . L ^{t d} .

AUG UST 3, 1944 F O U N D R Y TRAD E JO U R N A L 5

you a re having tro u b le w ith p ro d u ctio n fro m y o u r CORE BLO W ING MACHINES

yo u r Cores STRIKE BACK in th e Moulds

m m

you ex p erien ce o bjectionable FUMES w hen c a s t i n g ...

you wish to IMPROVE THE FINISH o f yo u r castings

u i

THE FORDATH ENGINEERING C!C

T E L E P H O N E :

WESt b ö o m w i c h0 5 4 9:2 l i ne s«

HAMBLET WORKS WEST BROMWICH

'mETALLICAL WEST BROMWICH

6 F O U N D R Y TR A D E J O U R N A L AUG UST 3, 1944

FOR

STEEL FOUNDRIES

To get th e most o u t o f y o u r men and e q u ip m e n t

you must have accurate boxes you must have s tr o n g boxes you must have d u ra b le boxes you m ust have STERLING boxes

In t h e s e d i f f i c u l t t i m e s m o r e f o u n d r i e s t h a n e v e r a r e t u r n i n g t o S t e r l i n g B o x e s t o h e l p s o l v e t h e p r o b l e m o f i n c r e a s e d p r o d u c t i o n .

T e le g ra m*: STERFLA SK ' B E D F O R D T e le p h o n e : B E D F O R D 5 3 3 8 /9

1 m L J ■ » LL J <

m i \m m smmms

L t M I T E D

B E D FO B/7

._

AUG UST 3, 1944 F O U N D R Y TRAD E JO U R N A L 7

D> * * Sto; cs • * * * * * * / n o ,,.

P ° s it iy e ¡a op e Zati 7 gui^ e r ;

d i Z d lU ° n S - T h e ° ? J n d u n a ffe c t e d b y Se a re

no

cupolas core an d m ould . j a r r ro llov er sand p re p arin g sand m ixing m ills ro tary sand dryers R oyer s an d m ixers d ry in g stoves m achin es p lants • ' sand disin te g rato rs ;. p o rta b le m o uld d ry e rs

1 L E C L I M I T E D - M a fe k in g R o a d - S m e t h w ic k - N e a r B IR M IN G H A M

f; ’A '

F O U N D R Y TR A D E J O U R N A L A U G UST 3, 1944

Manufactured to customers’ requirements. Can be relied on implicitly for uniformity of analysis. Also High Manganese Pig Iron, for use in Basic Lined Open Hearth Furnaces, and Foundry Pig Iron for special work, such as Cylinder Castings, etc. Enquiries invited.

CONSETT IRON COMPANY LIMITED

T E L E P H O N E : C O N S E TT 341 (10 lines) TELEGRAMS : STEEL. PH O N E , C O N SE TT

AUG UST 3, 1944 F O U N D R Y TRAD E J O U R N A L 9

MAGNETIC MOULDING MACHINE

U T IL IS E S E L E C T R IC IT Y A S T H E D IR E C T P O W E R M E D IU M

FO R H IG H P R O D U C T IO N W O R K

ROLL-OVER TYPE

MAGNETIC MOULDING MACHINES

BRITISH PATENT No. J21777.

B.l . M agn etic M oulding M achines h a v e fou r o u tsta n d in g fe a tu re s w h ich re s u lt ip fo u r vitally im p o rta n t p ro d u c tio n fa c to rs —s p e e d , a c c u ra c y , ec o n o m y a n d re lia b ility . By th e utilisation of ele c tric ity a s th e d ire c t p o w e i m ed iu m , the m axim um o u tp u t o f a c c u ra te m oulds is e c o n o m i­

cally atta in e d w ith the m inim um of m an ual effort.

W ith ‘‘r o llin g -o v e r” p e r fo rm e d be fo re sq u e e z in g , all p o ssib ility of d isto rtio n is elim in ated . A u to ­ m atic s trip p in g o n to th e c o n v e y o r also allow s th e o p e r a t o r ’s atten tio n to b e c o n c e n tra te d fully o n m ou ld p ro d u c tio n . W rite for leaflet M .115.

B R I T I S H I N S U L A T E D C A B L E S L T D .

P R E S C O T — L A N C S . T e l e p h o n e P R E S C O T 6 S 7 1 .

N.R.S. Trds “ NEWSTAD” RECIRCULATION SYSTEM

— N.R.S. STOVES—

for Efficiency, Quality and Economy

Types for any capacity and Foundry condition Mould and C o re Stoves, new and conversions

w it h guaranteed results fo r coke, coal, gas o r oil

N.R.S. Heating Units and N. M O U L D DRIERS --- H o t A ir Units for Skin Drying ---

Sole S u p p lie r s :

MODERN FURNACES & STOVES LTD.

B O O T H S T R E E T , H A N D S W O R T H , B IR M IN G H A M 21 T e l. : S m ethw ick 1334 ’ G ra m s: M ofu sto lim Every N.R.S. C o n ve rsio n

doubles th e o u t p u t and saves at least 5 0 % on

Fuel C o n s u m p tio n

10 F O U N D R Y TRAD E J O U R N A L

The vital needs o f war-time materials, treated by the production have m ade un- Bradley Spun-refining Pro- precedented demands upon cess and subject to chem ical i castings. W ithout the re- analysis and mechanical and search work on pig iron metallurgical test at every j carried out in the past, they stage of production, will

| cou ld nothavebeen fulfilled . m ake possible the com ing }, High duty castings will play renaissance o f Iron. We I an increasingly important shall be glad to discuss-the part in reconstruction after future o f high duty castings

• the war and pig irons, made in relation to your own ' f r o m t h e b e s t o f raw requirements.

B R A D L E Y & F O S T E R lid

DARL ASTO N . S O U TH ST A FFS

{

B l e n d e d “ A ll M in e ” p i g i r o n . H i g h c a r b o n s t e e l p i g i r o n . F i r e - r e s i s t i n g p i g i r o n .

AU G UST 3. 1944 F O U N D R Y TRADE JO U R N A L

T O T T E N H A M 4522. T A . ! “ K E IT H B L A C P H O N E L O N D O N .”

K E IT H B L A C K M A N L T D ., M IL L M EA D R O A D , L O N D O N , N.I7. T N .

T E L E P H O N E S : . T e le g r a m s :

M O L E S E Y 3111-2 ~ M E T A S T E IN A , P H O N E . L O N D O N

A new re-circulating FAN for

H EA T TREA TM EN T FU RN ACES

T h is n e w p a t e n t e d u n i t is a v e r y s tr o n g ly c o n s tr u c t e d p r o p e lle r t y p e fa n fo r in t e r n a l c ir c u la tio n o f h ig h te m p e r a tu r e g a s e s a n d a ir o n v a r io u s t y p e s o f h e a t t r e a t m e n t fu r n a c e s . C o n s tr u c te d in s h e e t or c a s t m e ta ls , a n d e x p r e s s ly d e s ig n e d for h a n d lin g e x tr e i, c ly h ig h te m p e r a tu r e g a s e s .

If y o u a r e in t e r e s te d , w e s h a ll b e p le a s e d t o s e n d y o u fu ll p a r tic u la r s . . - -z:-.f .

• : " r '

RO TARY FURNACES

F IR E D B Y F U E L O IL

T O W N S G A S

“ P U L V E R IT E ” O R

C R E O S O T E P IT C H

M IX T U R E

STEIN & A T K IN S O N L TD

47, W O L S E Y R O A D ,

E A S T M O L E S E Y , S U R R E Y .

F O U N D R Y T R A D E J O U R N A L a u g u s t 3,

For new light on darkroom problem s

— c o n s u l t

K O D A K

For many years an advisory service on darkroom lay-out has been part o f the Kodak contribution to successful photo­

graphy. Today Kodak still offers the advice o f experienced specialists in plan­

ning darkrooms which will promote the most efficient and economical working in any individual circumstances.

* Kodak provides a comprehensive range o f specialised darkroom equipment for

industrial photography and radiography, and the specialists who have created this range are well fitted to advise on the choice and use o f equipment, and on the planning o f a darkroom lay-out.

W hen you are considering the installation o f new darkrooms or the modification o f existing ones, seek the advice o f Kodak : this advice will at all times be gladly and freely given.

KODAK LIMITED, (X -ray S a les), KINGSW AY, LONDON, W.C.2

AU G UST 3, 1944 F O U N D R Y TRAD E JO U R N A L 13

( ( R A M O L I T H ^{t f}

NO CONTRACTION (R E G IS T E R E D )

F U S IO N P O IN T

1710°C.

NO EXPANSION

T H O M A S E. G R A Y & C O . LTD.

G R A N B Y C H A M B E R S , K E T T E R IN G

E S T A B L IS H E D 187 7 .

14 F O U N D R Y T R A D E J O U R N A L AUG UST 3, 1944

A New Tool for Industry!

% Y o u ’ll c h o o s e a n E L E C T R I C t r u c k b e c a u s e in b r e a k in g th ro u g h m a ter ia l-h a n d lin g b o ttle n e c k s — in sa v in g m a n p o w er, tim e an d m o n e y — e le ctric tru ck s h a v e b een pro v ed to offer d e fin ite a d v a n ta g e s o v e r a ll o th e r ty p e s b y v ir tu e o f th eir s ile n c e —i n s t a n t s ta r tin g a n d ra p id a c c e le r a tio n

— fre ed o m fro m fu m e s, w a te r freezin g and fire risk .

0 Y o u ’ll c h o o s e a n E L E C T R I C E E L t r u c k b e c a u s e for sheer r o b u stn e ss, r e lia b ilit y , sp e ed a n d m a n o eu v ra b ility it le a v e s all o th er s sta n d in g . N o te th e e x c lu s iv e in s tin c t iv e ste er in g o p e r a te d b y b o d y w e ig h t o n th e la te r a lly tiltin g p la tfo r m , a v o id in g f a tig u e an d afford in g g r ea t d e lic a c y an d a c cu ra c y o f d ir e c tio n a l c o n tr o l . . . th e r o b u st a ll-w e ld ed c o n s tr u c tio n . T h e d ir e c t-to - w h e e l d riv e e lim in a te s trans_

m issio n tr o u b le s an d r ed u ces p o w er lo ss.

Electric Eel Trucks are functionally designed for each job they have to do—and built to give many years of strenuous service.

The production programme includes types for every ind u s tr y—

write for full details.

S T E E L S E N G I N E E R I N G P R O D U C M e c h a n i c a l H a n d l i n g D i v i s i o n , C r o w n W o r k s , S u n d e

GABRIEL & ^{C o . L t d .}

T elephone N o. :

B IR M IN G H A M .

A S TO N CROSS 0756/7/8 ■ ■ ■— G ABRIEL, B IR M IN G H A M

BEG TO ADVISE THE ENGINEERING AND ALLIED TRADES THAT THEY ARE WOW IN A POSITION TO SUPPLY

SMALL

ALLOY STEEL CASTINGS

(5 to 40 Lbs.)

M A Y WE R E C E IV E Y O U R E N Q U I R I E S ?

A L L C O M M U N I C A T I O N S T O T H E REG. O F F IC E S , 4 & 5, A . B. R O W , B IR M IN G H A M . I N D U S T R I A L T R U C K S DÍSIGNCD AN O BUILT TO SOLVE INTERNAL TRANSPORT P KO Bl lM S

AUG UST 3, 1944 F O U N D R Y TRAD E JO U R N A L 15

REFRACTORY CONCRETE

REFRACTORY AGGREGATE BONDED WITH HIGH ALUMINA CEMENT

¿ s ta b /is h e d /Ç 0 2

w it h w h ic h IS in c o rp o ra te d T H E IR O N A N D STEEL TRADES JO U R N AL

NO P R E F IR IN G NO S H R IN K A G E R E A D Y FO R USE

IN 24 H O U R S

NON-SPALLING

R efra cto ry C o n crete is n o n - spalling under the most violent c o n d itio n s o f therm al sh o c k . Refractory Concrete can be cast into any shape and practically a n y s iz e , t h u s v er y la r g ely , e lim in a tin g tro u b le s d ue to

joints.

I M M E D I A T E L Y A V A I L A B L E

L A F A R G E A L U M I N O U S C E M E N T C O M P A N Y L IM IT E D

I T H E K ILN S, R IPLEY , SU R R E Y . ' PH O N E : RIPL E Y 313,9

i v

3-789

4 9 , W e llin g to n S tr e e t, L o n d o n , W .C .2 .

W A R T IM E ADDRESS t o w h ich all c o m m u n ica tio n s sh o u ld b e s e n t i—

3 , A m e r i h a m R o a d , H I G H W Y C O M B E , B u c k s .

’G ra m s i “ Z ac a te c a s, H igh W y c o m b e .”

'P h o n e i H IG H W Y C O M B E 1792 (3 lin es).

PU B LISH E D W EEK LY i 21s. p e r a n n u m (H o m e a n d O v e r s e a s ) OFFICIA L O R G A N O F i

C O U N C I L O F I R O N F O U N D R Y A S S O C I A T I O N S C h a irm a n i F ltz H e r b e rt W rig h t, T h e B u tte rle y C o m p a n y . R ipley, n e a r D e rb y . S e c re ta ry I V. D e lp o rt, 2, C a x to n S tr e e t, W e s tm in s te r , S .W .I.

P a rtic ip a tin g Associations I B ritish B atn M a n u fa c tu re rs ’ A s s o c ia tio n ; B ritish I r o n f o u n d e rs ’ A sso c ia tio n ; B ritish M alleable T u b e F ittin g s A s s o c ia tio n ; C a s t Iro n A x le b o x A sso c ia tio n ; C a st Iro n C h a ir A sso cia­

tio n ; C a s t Iro n H e a tin g , B o ile r an d R a d ia to r M a n u fa c tu re rs ’ A sso ciatio n ! C a s t Iro n S e g m e n t A s s o c ia tio n ; G re e n s a n d Pip e F o u n d e r s ’ A sso c ia tio n of S c o tla n d ; I ro n f o u n d e rs ’ N a tio n a l C o n f e d e ra tio n ; N a tio n a l A sso cia­

tio n o f M alleable Iro n fo u n d e rs ; N a tio n a l In g o t M ould A sso c ia tio n ; N a tio n a l Iro n fo u n d ln g E m p lo y e r s ’ F e d e r a t io n A s s o c ia tio n o f A u t o ­ m o b ile a n d A llied H ig h D u ty I r o n f o u n d e r s ; B ritish C a s t Iro n R e se a rc h A sso c ia tio n (a ffilia te d ); B ritish G r i t A sso c ia tio n (affilia te d );

F lu sh in g C i s te r n M a k e rs ’ A s s o c ia tio n (affiliated ) ; I n s t i tu t e o f B ritish F o u n d r y m e n (a ffilia te d ). _____

I N S T I T U T E O F B R I T I S H F O U N D R Y M E N P R E S ID E N T , 1943-44 ; D . S h a r p e , F o u n d r y P la n t & M a c h in e ry , L td . 113 W e s t R e g e n t S t r e e t , G la sg o w .

G e n e ra l S e c re ta ry i T. M ak em so n . A c tin g S e c r e t a r y , J. B o lto n S aint Jo h n S tr e e t C h a m b e rs , D e a n sg a te . M a n ch e ster 3.

BRAN CHES

B irm in g h am , C o v e n try and W e s t M idlands I A. A. T im m in s, F.I.C . 3 3 . C a r t e r s L a n e , Q u i n t o n . B r is to l a n d W e s t of E n g la n d ; A.

H a re s, 2 0 , G r e e n b a n k R o a d , H a n h a m , B risto l. E. M idlands I S. A.

H o r to n “ T h r e e ,” M o styn A v e n u e , L lttle o v e r , D e rb y . Lancs : H . B u c k ­ ley , E lle s m e re , N o r f o lk A v e n u e , B u rn le y . L o n d o n : V. C . F a u lk n e r, 3, A rn ersh am Road. H igh W y c o m b e . M id d le sb ro u g h (pro tern.) : J. K.

S m ith so n , N o r th -E a s te r n Iro n R efining C o m p a n y , L im ite d , S tillin g to n , S to c k co n -o n -T e es. N e w c a s tle -u p o n -T y n e : C . Lashly, Sir W . G . A rm ­ s tr o n g , W h it w o r t h & C o . ( Iro n fo u n d e rs ), L td ., C lo se W o rk s , G a te sh e a d S c o ttish i J. Bell, 60, S t. E noch S q u a re , G lasg o w . Sheffield ; T . R. W al k e r , M .A ., E n g lish S te e l C o r p o r a t i o n , L t d ., S h effield . W a le s and M o n m o u th i A. S. W a ll, 14, P a la c e A v e n u e , L lan d aff, C a rd iff. W e s t Riding o f Y o r k s h ir e : D o u g la s J e p s o n , M .Sc., 9 , A m b le s id e A v e n u e , B ra d fo rd . Souch A frica : B. P. S k o k , M u tu al Building, J o h a n n e s b u rg .

SEC TIO N S

B u rn ley t H. B uckley, E lle s m e re , N o rfo lk A v e n u e , B u rn ley , Lancs.

C a p e T o w n : K. Z w a n z K e r , P .O . B ox 3 46, C a p e T o w n , S. A frica.

East A nglian i A . N . S u m n e r , 5 1 6 , N o r w ic h R o a d , Ipsw ich F a lk ir k : T . R. G o o d w in . “ V le w fie ld ,” F alk irk R oad, B o n n y b rld g e. L incoln i E.

R. W a lt e r , P h .D ., T h e T ech n ical C o lle g e , Lincoln.

A S S O C I A T I O N O F B R O N Z E A N D B R A S S F O U N D E R S P r e s i d e n t : H . B issell, J. S to n e & C o ., L td ., L o n d o n . S e c r e t a r i e s : H e a th c o te & C o le m a n , 2 5 , B e n n e tts H ill, B irm in g h a m , 2

T H E I N S T I T U T E O F V I T R E O U S E N A M E L L E R S P re s id e n t : W . H . W h it t le , W . H . W h it t le , L im ite d , Eccles, n e a r M a n c h e s te r. C h a irm a n j W . T o d d , P a r k in s o n S to v e C o ., L td ., S te c h - f o r d , B irm in g h a m . H o n . Sec. i W . T h o m a s, A .I.C ., B a n k H o u s e , H igh S t r e e t , R ic k m a n s w o r th , H e r ts .

F O U N D R Y T R A D E S ' E Q U I P M E N T A N D S U P P L I E S A S S O C I A T I O N

P re s id e n t I G . E. F ran ce, A u g u s t’s, L im ite d , T h o rn T r e e W o r k s , Halifax. H o n o r a r y S e c r e t a r y : K. W . B rid g es. A s s ista n t S e c re ta ry i Miss L. C o x , 52, S u rb ito n H ill P a rk , S u rb ito n , S u rre y .

W E L S H E N G I N E E R S ’ A N D F O U N D E R S ’ A S S O C I A T I O N P re sid e n t i W . E. C le m e n t, C .B .E., M orfa F o u n d ry , N e w D o c k , L lanelly.

S e c re ta ry : J- D. D . D avis, I, S t. Jam es G a rd e n s , S w ansea.

B R I T I S H C A S T I R O N R E S E A R C H A S S O C I A T I O N A l v r c h u r c h , B ir m in g h a m . ’P h o n e a n d ’G r a m s : R e d d itc h 7 1 6 . S c o t ti s h L a b o r a to r ie s F o u n d r y T e c h n ic a l I n s t i t u t e ,M e e k ’s R o a d , F t l k l r k . (P h o n e i 332,}

16 F O U N D R Y T R A D E J O U R N A L AU G U S T 3, 1944

T h e n eed fo r all p o s s ib le c o n s e r v a t io n o f m a n p o w e r ; th e d em a n d fo r th e m a x im u m o u t p u t o f v ita l c a st m e ta llic p r o d u c ts ; th e in s is te n c e u p o n th e lo w e s t c o s t o f p r o d u c ­ t io n ; and th e n e c e s s ity o f m a in ta in in g , an d e v e n im p r o v in g , th e q u a lity o f th o s e p r o d u c ts .

A ll th e se c o n d it io n s c o m b in e to p o in t to th e o n ly sa tisfa c to r y s o lu t io n to all th e s e p r o b le m s —

MECHANISATION

b u t it m u s t b e m e c h a n is a tio n p a r tic u la r ly c o n sid e r e d , d e sig n e d and a d a p ted to th e in d iv id u a l s ite c o n d it io n s ; to th e p a rticu la r p r o d u c t ; and w ith fu ll regard to a ll th e fa cto r s, e c o n o m ic , g e o g ra p h ica l and h u m a n , w h ic h m ay have any b earin g o n th e p r o b le m .

In o th e r w o r d s c o n s u lt :—

'

“ The S pecialists in F o u n d ry M ech an isation ”

w h o s e p r o d u c ts

“ Set th e S tandard b y w hich F o u n d ry Plant is ju d g e d .”

LIM ITED

’P h o n e s : 6 1 2 4 7 & 8

HALIFAX, EN G LA N D

V ol. 73 Thursday, A u g u s t 3, 1944 N o. 1459 WITH WHICH IS IN C OV O JU rEO T H E I R O N A N D S T E E L T R A D E S J O U R N A L

e s ta b lis h e d 19 0 2

The T.A.P.

We understand that after four years’ continuous work the Technical Advisory Panel to the Directors for Iron Castings of the Iron and Steel Control, Ministry of Supply, is being wound up, it having completed the work for which it was originally formed.

In July, 1940, Mr. Fitzherbert Wright, then Director for Iron Castings, appointed an Advisory Panel consisting o f four members to assist him and industry in meeting the situation likely to arise due to curtailment of normal supplies of raw materials, and to assist firms in the maintenance of quality under wartime conditions. The T.A.P. rapidly grew in size until it included eighteen members, with representatives of the Institute o f British Foundrymen, the British Cast Iron Research Association, S.T.A.M., and other official bodies.

When Mr. Fitzherbert Wright retired from the post of Director for Iron Castings, the T.A.P. continued to function under the new Joint Directors, Mr.

E. A. Chell and Mr. T. Makemson. During its existence the T.A.P. has had 35 formal meetings, and it is a tribute to the enthusiasm of the indi­

vidual members that in spite of blitz, fog and storm, the average attendance o f members at these meetings has been close on 80 per cent. Many authorities have already paid tribute to the excellent work done by the ironfoundry industry under wartime conditions in the maintenance of quality of output. It can fairly be stated that whereas in the last war the quality o f iron cast­

ings seriously deteriorated, in the present war the quality o f castings has been maintained and where necessary has been substantially raised- The T.A.P. among others can claim a share in bringing about this satisfactory state of affairs.

In its early days the T.A.P. assisted the Control in the allocation of quality grades o f pig-iron to special jobs, and assisted industry in maintaining production with the increased proportion o f native iron, most of it of high-phosphorus content, which it was obliged to use. The production of indi­

vidual items such as trench mortar bombs was in many cases assisted by personal visits by members o f the Panel. As the work o f the T.A.P. grew,

much of it was allocated to Sub-Committees. One of the first fruits of the Panel’s work was the publication of the data book on cast iron issued by the British Standards Institution under their No. 991. This book summarises information on the various grades of cast iron available. It was prepared to supply information suitable for de­

signers and engineers, and having in mind especially the requirements of the Service departments, and with particular reference to cases where cast iron was adopted as a substitute for other metals in short supply. A considerable amount of the T.A.P.’s activity has been concerned with the pro­

duction of malleable castings and special activities of the Sub-Committees have dealt with items such as the regeneration of spent annealing ore, with the influence of residual elements, and modifica­

tions in refined and other pig-irons, and with the trouble encountered for a time with “ peel ” in malleable castings.

Another Sub-Committee of the T.A.P. has for some time past been studying the impact properties of cast iron with a view to learning more of its behaviour under shock, and with a view to de­

veloping a satisfactory general test for use throughout the industry. Details of a recom­

mended procedure for the test were published in

T h e F o u n d r y T r a d e J o u r n a l , July 22, 1943.

This work is now nearing completion, and will, it is hoped, result in a standardised method of carry­

ing out the impact test for cast iron. Other Sub-Committees have looked after the interests o f the foundry industry in relation to moulding materials, and throughout the war period liaison

{Continued overleaf, column 2.)

Contents

The T.A .P., 267—Correspondence, 268.—An Outline of Gravity Die-Casting, 269.—D isposal of Surplus Government Stores, 274.—Future for L ight Metals, 274—British Fluorspar Producers’ Association, 274.—Sandslinger M oulding Practice,

275.—Ironfoundry Fuel News—X IV , 278.—New Catalogue,

278.—N otes from the Branches, 278 —Underfeed Stokers for M etallurgical H eatin g Furnaces, 279—N ews in Brief, 280.—

E ssential Work Order Amendment, 280.—Company Results, 282.—Obituary, 282.—Raw M aterial Markets, 284.

E

268 F O U N D R Y TR A D E J O U R N A L A U G U il J, 17*ft

C O R R E S P O N D E N C E

[ W e a c c e p t no r e s p o n s i b i l i t y fo r t h e s t a t e m e n t s m a d e or the o pin io n s e x p r e s s e d b y our c o r r e s p o n d e n t s.]

P U B L IC IT Y F O R B R IT A IN

T o th e E d ito r o f Th e Fo u n d r y Tr a d e Jo u r n a l. Si r,— W ith in 12 to 18 m o n th s o f th e cessation of hostilities in E u ro p e, w ould it n o t be a m o st v alu ab le a d d itio n to any B ritish p ro p a g an d a to organise a series o f co m p reh en siv e e x h ib itio n s in som e dozen o r so C o n tin e n tal cities— such e x h ib itio n s to hav e as th eir p u rp o se th e stim u latio n o f p ro -B ritish feeling? I re ­ m em b er w ell som e 35 years ago, w hen Sir G eo rg e A skw ith w as Presid en t o f th e B o ard of T rad e, he was very keen on the idea o f ru n n in g e x h ib itio n s in several c ap ital cities on the C o n tin e n t, a n d h e did, in fact, do so. T h is tim e I sh o u ld lik e to see a fa r m o re a m b i­

tious schem e— e x h ib itio n s a t each o f w hich w o u ld be show n B ritain’s im m ense in d u stria l ach iev em en t in w a r­

tim e, an d w h at B ritain can offer fo r the fu tu re. I visualise, fo r exam ple, as w ell as th e u su a l in d u stria l sto ry , such things as a re p e rto ry th ea tre , an d cinem as show ing th e b est B ritish film s, ex h ib its of typical B ritish E m p ire fe atu res— a ll p resented u n d e r the m a n ­ agem ent o f the very best im pressarios, such as N o el C o w ard , C. B. C o ch ran , a n d J o h n G ielgud. E ach ex h ib itio n sh o u ld be the ev en t o f the y e ar in th e cities an d co u n tries selected. W e c an n o t h o p e to take B ritain over to th e C o n tin e n t in a m o re exciting w ay, an d th ere is no w ay o f brin g in g the C o n tin e n t h ere.—

Y ours, etc.,

Cl a u d e W . Be l l. 21, D u k es Lodge,

H o lla n d P ark , W .l l.

July 22, 1944.

B U IL D IN G U SE S D E P A R T M E N T T o th e E d ito r o f Th e Fo u n d r y Tr a d e Jo u r n a l. Si r,— In re ce n t lead in g articles yo u have, rig h tly I think, in d ic a te d som e concern in the in d u stry o ver the p u b lic’s re actio n to-d ay to cast iro n w here this m aterial is u sed in b u ilding o r b u ilding e q u ip m e n t a n d fittings, including d om estic as w ell as b u ild in g uses. T h e p ublic k n o w little o f the m an y efficient uses o f this m aterial, o f all the m etallurgical re sea rch w ork th at h as p ro d u ced cast iro n o f a lm o st an y re q u ire d stren g th a n d w ith m an y sp len d id finishes, clean, h a rd , sim ple a n d b e au tifu l, a n d do n o t realise th a t m o d ern b u ild in g can, a n d does, in c o rp o ra te these. T h ey a re influenced by the q u a lity o f m a te ria l a n d q u ality o f design of th o se p a rts o f a b u ild in g a n d its eq u ip m e n t th a t can be seen an d h a n d led . U n fo rtu n a te ly , this q u a lity of m ate ria l h as o ften been low er th a n w as advisable, an d the re co rd o f design in cast iro n fo r b u ilding a p p lic a ­ tio n s c an show little evidence o f im p ro v e m en t on the fussy re p ro d u c tio n w o rk of 50 years ago.

T h u s th e pu b lic to -d ay are a p t to th in k o f c ast iron as a cheap, brittle, o ld -fash io n ed m ate ria l w ith plen ty o f k n o b s, scrolls an d enrichm ents to catch d irt an d d ust, w hilst technical o p in io n to -d ay seem s to b e som e­

w h a t c o n cern ed w ith th e w elter o f n ew m ate ria ls th a t

a p p ea r likely to take the place of cast iro n in the n e a r fu tu re — p a rtic u la rly plastics, glass, asbestos, pressings, etc.

T h e M in istry o f W o rk s an d B uildings h a s suggested th a t B ritish S ta n d ard S pecifications fo r c ast-iro n e q u ip ­ m en t be set up, d ealing w ith sizes a n d q u a lity of m aterial. T h e la tte r m ay be difficult, b u t is obvio u sly o f im p o rtan ce. I t is o f even g re ater im p o rta n c e th a t th e design o f cast-iro n g o o d s s h o u ld h a v e th e serious stu d y a n d atten tio n , o f c o m p e te n t designers. T h e re are v ery few , if an y , cast-iro n a rticles o f e q u ip m e n t in building th a t co u ld be im p ro v ed fro m th e practica l, en g in eerin g o r fu n c tio n a l p o in t o f view by th e su b sti­

tu tio n o f an y o f the new er m ate ria ls. B u t if the d e­

sign o f articles in the new m ate ria ls is so m u ch better a n d m o re attrac tiv e , the pu b lic w ill p re fe r th em in spite o f th e basic m ate ria l being less efficient. I f th a t p o r­

tion o f a g re at in d u stry dealin g w ith b u ild in g m aterials an d eq u ip m e n t will be c arefu l o f the q u a lity of cast iron an d really c o n cern ed a b o u t design, it need n o t fe ar an y co m p etitiv e m ate ria ls.— Y o u rs , etc.,

D . L. Br i d g w a t e r. C o n su ltin g A rchitect.

B u ild in g U ses D e p a rtm en t,

B ritish C a st Iro n R e se a rc h A sso ciatio n , A lv ech u rch . B irm in g h am .

Ju ly 21, 1944.

T H E T.A .P .

(C o n tin u e d fr o m p re v io u s page.)

has been maintained with the Service departments with regard to production problems on iron cast­

ings. Much o f the work carried out by the T.A.P.

has for security reasons been available immediately only to those directly concerned, but it is hoped that when happier times return a great deal of the work now in report form can be published for the benefit o f the industry as a whole. There is no doubt that during its existence the T.A.P., although working in the background, has been of real service to industry and to the Iron and Steel Control. It was set up in the first place in anticipation of difficulties before the industry arising from wartime conditions, and the fact that specification limits for castings are higher to-day than at the beginning of the war is a tribute to the healthy state of the ironfoundry industry, towards which the T.A.P. has played no incon­

siderable part.

A ttendances at the a n n u a l c o n feren ces o f th e In s ti­

tu te o f B ritish F o u n d ry m a n sink in to insignificance c o m p a red w ith the m eetings A m erican F o u n d ry m e n ’s A sso ciatio n . F o r the B uffalo C ongress n o few er th a n 6,000 v isitors w ere ex p ected . N a tu ra lly , th ere w as a sh o rta g e o f a cc o m m o d a tio n .

7 0 U N D R Y TRAD E JO U R N A L 269

AN OUTLINE OF GRAVITY DIE-CASTING

By M. R. H IN C H C L IF F E

* A general survey o f development in its application

T h e p rogress of fo u n d ry technology in recen t years h as been g reatly accelerated by the d e v elo p m en t of h ig h ly specialised casting m eth o d s differing w idely in p rinciple to th e accep ted sand-casting p ractice, re su lt­

ing in n o th in g less th a n a re v o lu tio n ary effect o n p ro ­ ductio n . M a n y o f th e o u tstan d in g achievem ents a tta in e d can b e a ttrib u te d to d ev elo p m en t in the tech n iq u e o f g ravity die-casting, o r p e rm a n en t m ould casting a s it is som etim es term ed.

G ra v ity die-casting is a process o f pro d u cin g m etal castings fro m p e rm a n en t m oulds, o r dies as th ey are g enerally called, u su a lly c o n stru cted in c ast iro n o r steel a n d designed in such a m a n n e r as to be read ily collapsible to facilitate rem o v a l o f th e solidified cast­

ing. T h e term “ g ravity ” die-casting im plies th a t the m eta l enters a n d fills th e m o u ld by v irtue o f its ow n w eight o r g ravity only, n o a d d itio n al pressure app ly in g devices being used. In this w ay the process differs fu n d a m e n ta lly fro m its allies cen trifu g al cast­

ing a n d p ressu re die-casting, w here, in th e fo rm er p ro ­ cess, p ressu re is created th ro u g h th e actio n o f ce n tri­

fu g a l fo rce actin g o n a ro ta tin g m ass o f m eta l a n d in the la tte r case w h e re th e m eta l is injected in to a highly finished m ech an ically o p e rated steel die, u n d e r the actio n o f in ten se h y d ra u lic p ressure.

Bv fa r the w idest a p p lic atio n o f gravity die-casting lies in th e m an u fa ctu re o f lig h t allo y castings, p a r­

tic u larly a lu m in iu m allo y castings fo r th e a irc ra ft a n d m o to r in dustries, an d it is f o r th is reaso n a n d because of the a u th o r’s p a rtic u la r experience th a t m o st o f the g eneral p rinciples an d p ractices ou tlin e d in this P a p er a re those relatin g to alu m in iu m alloy gravity die- casting.

B efo re casting, gravity dies f o r alloys, o th er th an co p p er alloys, are specially p re p a re d by h eatin g u p to a tem p e ra tu re sufficient to tak e o n a sp ray o f re fra c to ry co atin g consisting o f w hiting a n d w ater w ith a little w ater glass. T h is serves as an in su lato r, preventing too ra p id chilling o f th e m eta l w hen in co n ta c t w ith the die, an d also as a venting m ed iu m in th a t it co n sti­

tu te s a p erm eab le la y e r o n th e die surface w hich facilitates escap em en t o f a ir tra p p e d betw een the m etal an d th e m o u ld , th u s allow ing the m etal to lie

“ k in d ly ” on the die. D ies f o r c o p p er b ase alloys are u su ally c o ated w ith co llo id al g ra p h ite. T h e h e a t given o u t b y th e m eta l in th e die cavity d u rin g solidification is alm o st in v ariab ly sufficient to m ain tain the die a t a u n ifo rm tem p e ra tu re th ro u g h o u t o p eratio n . O n co m ­ p letio n o f th is th e dies a re h e a te d by m ea n s o f eith er gas flam es o r m uffle fu rn ace s to a tem p e ra tu re of betw een 250 a n d 350 deg. C ., a t w hich th ey are read y f o r o p eratio n .

• E x t r a c te d fro m a P a p e r r e a d b efo re th e S co ttish B ra n c h o f th e I n s tit u te o f B ritis h F o u n d ry m e n .

Advantages o f Die-Casting

Producing castings fro m gravity dies is a co n tin u o u s m an u a l o p e ratio n a n d due to the n a tu re o f the m aterial fro m w hich the m o u ld s are m ad e thou san d s o f good castings can be m ade fro m the sam e die a t a c o m p a ra ­ tively h ig h rate o f p roduction. W hen one re fers to gravity die-casting as p erm an en t m o u ld casting as is the practice in the U.S.A . and on the C o n tin en t, this is n o t to say th a t th e m o u ld s last indefinitely; the inevitable w ear takes place resulting in loss of accuracy, rep airs have to be m ade an d in certain cases a com plete replacem ent m ay be necessary befo re the die has p ro d u ced its q u o ta o f castings; the a ctu al die life depending, o f course, o n the n a tu re of the allo y being cast a n d the in tricacy o f the com ponent.

T h e o u tstan d in g advantages o f gravity die-casting o ver sand casting a re as follow :— (1) G re atly in­

creased rate s o f p ro d u ctio n ; (2) p ro d u ctio n of castings to consistently clo ser lim its o f dim ensional accuracy w ith im proved surface finish; an d (3) enhanced m echanical p ro p erties of the casting.

T h e econom ic savings resulting fro m the hig h er rates o f p ro d u ctio n fro m gravity dies as against sand m oulds is p erh ap s the m ost o u tstanding advantage of the process a n d o n e w hich, it is p ro b a b ly tru e to say, has influenced its progress m o re th an anything else.

T his is because financial c o n sid eratio n s u sually p re­

d o m in ate w hen view ing th e relativ e m erits o f m an u fac­

tu rin g m ethods, alth o u g h in certain instances other facto rs o f no econom ic significance m ay decide the issue, particu larly in th e case o f specialised a irc ra ft co m p o n en ts w here stren g th an d accuracy are o f p a ra ­ m o u n t im portance.

T h e m ain ten an ce o f closer lim its o f dim ensional accu racy as a second adv an tag e o f g ravity die-casting is a fu n ctio n o f the p erm an en cy o f the m oulds, the a ccu racy w ith w hich they can be m ach in ed and the extent to w hich c o n tra c tio n o f the casting can be co n ­ trolled. A llow ing fo r all these v a riables, die-castings c an b e p ro d u ced to a n accu racy o f + 0.010 in. T he co n tro l o f casting dim ensions to such fine lim its is of im m ense value to p ro d u ctio n engineers m achining large q u an tities of castings by m ass-p ro d u ctio n m ethods, in th a t adv an tag e can be tak en o f the c o n ­ sistency in th e use of jigs locating fro m p re d e ter­

m ined faces on the casting and the red u ctio n in the m achining allo w an ces necessary.

Im provem ent in M echanical Properties F in ally , a s the s tre n g th o f an allo y is largely d e ter­

m ined by the size o f the grains or crystals c o n stitu t­

ing the m ass, w hich in tu rn is, to a g reat extent, governed by the rate o f cooling o f the allo y during the process o f solidification, the fact th at a gravity die

270 F O U N D R Y T R A D E J O U R N A L AU G UST 3, 1944

G ravity D ie-Casting

is v irtu ally one large chill re su lts in the p ro d u c tio n o f c astin g s h av in g a very fine g rain ed stru c tu re . T h e re su lta n t im p ro v e m en t in m ech an ical p ro p e rties is very m ark ed ; fo r instance, the u ltim a te tensile stre n g th o f a lu m in iu m allo y N .A .226 (fully h e at-tre a te d ) is in ­ creased fro m 18 to 24 to n s p e r sq. in. w h en die cast, the p ercen tag e e lo n g a tio n in creasin g fro m 4 to 9. W ith R .R .50 the figures a re 11 to n s per sq. in. u ltim ate tensile, stren g th a n d 2.5 p e r cent, elo n g a tio n in the sa n d -cast co n d itio n ; 12.5 to n s p e r sq. in. u ltim a te tensile stren g th an d 4 per cent, e lo n g a tio n in the die- cast state.

T h e value o f g ravity die-casting is lim ite d in one sense by the larg e in itia l co st o f th e die c o m p a red w ith the cost o f w o o d o r m etal p a tte rn e q u ip m e n t in sand -castin g p ractice. F u rth e rm o re , once a die h as been m ach in ed an d c o n stru cted , a m a jo r a lte ra tio n to the design o f the co m p o n e n t w o u ld be disastro u s, as this w ou ld e ith e r m ean m ak in g a new die o r re p la c ­ ing c ertain p a rts o f th e o b so le te one.

W hen this p ro b lem is a p p ro ac h e d b ro ad -m in d ed ly , how ever, die cost is n o t q u ite s o p ro h ib itiv e as it m ay

tio n , w ith a re s u lta n t increase in die cost, a n o rd e r of m an y th o u sa n d s o f castin g s w o u ld b e n ecessa ry to m ak e the jo b a pro fitab le p ro p o sitio n .

A fu rth e r d ra w b ac k is in tro d u c e d w ith the use of alu m in iu m alloys in th a t a lo w er yield o f finished castings to ro u g h castings is o b ta in e d th a n in sand casting, due to the p a rtic u la r casting te c h n iq u e n e ce s­

sa ry fo r these alloys. T h is in v o lv es m eltin g large

Fi g. 1.— Re p r e s e n t a t i v e Gr o u p o f Gr a v it y Di e- CASTINGS FO R H E A V Y V E H IC L E E N G IN E .

a t first a p p ea r. A ssum ing first o f a ll th a t the design o f the co m p o n e n t w ill re m a in re aso n a b ly sta n d ard an d given d em an d s fo r larg e q u a n tities, w h en th e c o st o f the die is divided am o n g st the n u m b er o f castings to be p ro d u ced , it ceases to be of an y g reat signi­

ficance.

T h e effect o f th e design o f the c o m p o n e n t o n th e m in im u m n u m b e r of castings w hich w ou ld w a rra n t die-casting is v ery im p o rta n t, the re a so n being th a t in c e rta in in stan ces a n o rd e r a s low as 200 m ay be suffi­

cient, w h ereas n o rm ally a t least 1,000 castings w o u ld be n ecessary. In th e case o f v ery larg e an d in tric ate c o m p o n e n ts w hen th e size a n d w eight o f th e dies w ould im pose the necessity of m ech an ical m a n ip u la ­

F i g . 2 .— D i e f o r “ L e y l a n d ” G e a r b o x S h o w n i n F i g . 4 in O p e r a t i o n .

q u a n titie s of m eta l w h ich m ay o nly yield o n e -h a lf o r o n e -th ird o f its w eight o f casting. T h e su rp lu s m etal in the ru n n e rs a n d risers is, ho w ev er, p e rfe c tly good m etal an d n eed o n ly be rem elted b e fo re being r e ­ used. T h e net loss is the co st o f m eltin g th e m etal, the re d u c tio n in the re a l m eltin g c ap a city a v ailab le an d the c o st o f rem o v in g the excess m etal fro m the castings.

Scope

T ech n ically , the scope o f g rav ity die-casting is very extensive; a lm o st an y m etal th a t can be san d c ast can be die cast, a lth o u g h it m ay n o t alw ays be p ra ctic a b le to do so. T h e fo llow ing classes o f allo y s a re die

AUG UST 3, 1944 F O U N D R Y TRAD E JO U R N A L 271

cast o n a co m m ercial scale:— (1) L o w -m elting-point a llo y s h av in g lead o r zinc base; (2) higher-m elting- p o in t a llo y s o f th e light allo y class, w ith alu m in iu m o r m ag n esiu m base; an d (3) high -m eltin g -p o in t alloys o f c o p p er base. C astin g s m ad e in the alloys o f class (1) are alm o st all o f th e w hite m etal type used fo r a u to ­ m obile a n d a irc ra ft engine bearings. A n u m b er of gravity die-castings are m ad e in z inc-base alloys, b u t these alloys- a re used alm o st exclusively fo r pressure die-castings.

T h e scope o f alu m in iu m -allo y gravity die-castings

T hese are m ade in an alu m in iu m allo y o f the fo l­

low ing c o m p o sitio n :— 4 per cent. Si, 2 per cent. C u, 2 per cent. N i, an d b alan ce Al. T he gravity die fo r the g earb o x visible in the to p o f the picture is show n in o p e ratio n in Fig. 2. T h e die consists o f two m ain die halves m o u n ted on a base, one large top core form ing the clu tch housing an d a co llap sib le c o re in nine p arts, th e com plete die w eighing 1 ton. C a st­

ings are p ro d u ced fro m this die a t the rate o f fo u r per h o u r, em ploying three m en. In changing over fro m sand-casting to die-casting, the sectio n al th ick ­ ness o f the casting w as red u ced by 25 p e r cent., an d a saving o f £1 2s. 7d. p e r casting w as effected.

Since the o u tb rea k o f w ar gravity die-casting has found extensive a p p lic atio n in a irc ra ft engine p ro d u c ­ tion, due to the d em an d fo r large q u an tities of cast­

ings in high-duty alu m in iu m a lloys to m eet rigid A ir M inistry specifications. T h e significance o f this is obvious w hen one realises th a t in the fam o u s Rolls- Royce M erlin aero engine n o less th a n ap p ro x im ately 80 p e r cent, o f the to ta l n u m b er o f castings on the engine are die-castings, the m ajo rity o f w hich are m ade in alu m in iu m allo y R .R .50 (D .T.D . 133B). A

Fi g. 3 .— Re p r e s e n t a t i v e Gr o u p o f Gr a v it y Die- c a s t i n g s f o r Ro l l s- Ro y c e Me r l i n En g i n e.

Fi g. 4 .— Ty p ic a l Se m i- Die-c a s t in g s w i t h t h e i r Sa n d Co r e s.

covers a very w ide field indeed, hav in g im p o rta n t ap p licatio n s in the a u to m o b ile a n d a irc ra ft industries.

In p eacetim e die-casting finds its w idest a p p lic atio n in the m a n u fa c tu re o f a larg e v ariety of castings fo r the m o to r-v eh icle industry. A lu m in iu m -allo y p istons fo r m o to r-cy cle, m o to r-c a r an d heavy-vehicle engines are m ade exclusively as g ravity die-castings, a n d w ere p ro b a b ly the first co m p o n en ts to be die-cast on a large co m m ercial scale. In an y m o d ern m otor-vehicle fa c ­ to ry exam ples of g rav ity die-castings m ay be fo u n d in the fo rm o f cran k cases, sum ps, gearboxes an d clutch housings. A g ro u p o f ty p ical g ravity die-castings fo r a w ell-know n heavy-vehicle engine a re illu strated in Fig. 1.

Fi g. 5.—Sh o w i n g Pr i n c i p l e o f Po u r in g in t o Ti l t e d Di e ( Dia g r a m m a t ic).

n u m b er o f such castings a re show n in Fig. 3, and include cy lin d er skirt, w eighing 53 lbs. in the finish- cast co n d itio n ; R o ck er C o v er, m ad e in L.33 alum i- nium -silicon alloy; fro n t gear casing, and top and b o tto m h a lf c a rb u re tte r bodies.

M agnesium Die-castings

M o re recently, a g reat deal o f a tte n tio n h as been directed to w ard s m agnesium alloys, in the founding o f w hich g ravity die-casting h as played a n im p o rtan t p a rt. T h e u n iq u e physical an d chem ical p ro p erties of m agnesium ren d ered the use of its alloys difficult and n o t w ith o u t d an g er w hen first attem p ted , w hich created ra th e r a stro n g p reju d ice against them . F o rtu n a te ly ,

272 F O U N D R Y T R A D E J O U R N A L AUG UST 3, 1944

G ravity D ie-Ca stin g

h o w ev er, th ro u g h th e a cc u m u la tio n o f know ledge fro m re se a rc h an d exp erien ce the casting ch ara cte ristic s o f these alloys is now m o re fu lly u n d e rsto o d an d p ro p e r tech n iq u e h a s b e en developed. C o n se q u e n tly m ag n e ­ siu m allo y castings fo r m an y p u rp o ses a re used o n a larg e scale. T h is is p a rtic u la rly m a rk e d in th e case o f die-oastioigs as a re su lt o f the d e m a n d fo r such in a irc ra ft stru c tu re s a n d e q u ip m e n t. T o -d ay , som e very larg e a irc ra ft lan d in g w heels are being m ad e a s g ravity diie-castings, a n d it need n o t be em p h asised th a t these hav e to be p erfect. P ro b a b ly , th e best e x am p le of m agnesium -aU oy die-casting on a larg e scale is the

Fi g. 6 .— Ty p i c a l Ca s t i n g s Ma d e f r o m Gr a v it y Di e s Ti l t e d Du r i n g Po u r in g.

m a n u fa c tu re o f th e incen d iary b o m b body. C olossal q u a n titie s o f bo m b s are being c o n tin u a lly p ro d u c ed by very in g en io u s a n d highly develo p ed p ro d u c tio n m eth o d s using g ravity dies.

Copper-base A lloys

T h e co m m e rc ial co p p er-b a se a llo y s o f class (3) len d in g th em selv es to g ravity die-casting are as fo l­

low :-—(a) A lu m in iu m b ro n z e; (6) b rass; (c) p h o sp h o r b ro n z e; a n d (d) silico n b ro n ze. T h e use o f this class o f a llo y s is acc o m p a n ied w ith g reat difficulties c o m ­ p a re d w ith th e o th e r alloys, due to the hiig.h po u rin g tem p e ra tu res involved. T h is re su lts in the ra p id b re a k ­ do w n o f the die su rfaces due to e ro sio n a n d th erm al fatig u e, finally resu ltin g in co lla p se a fte r a c o m p a ra ­ tively sh o rt die life. By the use of special allo y iron

o r steeil dies, h o w ev er, th e effect o f h ig h te m p e ra tu re is re n d e re d less h a rm fu l.

A lu m in iu m b ro n z e is a n allo y w h ic h is finding m o re an d m o re im p o rta n t a p p lic atio n s in e n g in eerin g , due to its re m a rk a b le m ec h an ic al a n d co rro sio n -re sistin g p ro p e rties, ft is n o t su rp risin g , th e re fo re , th a t th ere are fo u n d m an y e x am p les o f a lu m in iu m -b ro n z e g ravity die-castings in th e a u to m o b ile , a irc ra ft an d ele ctric a l in d u stries. T h ese a r e c h a ra c te ris e d by good definition a n d su rfa ce finish. T h e ch illin g effect o f the die re su lts in a m ark e d re d u c tio n in th e g ra in size, w ith c o rre sp o n d in g in cre ase in th e m ec h an ic al stren g th a n d h ard n ess.

B rass g rav ity die-castings a re also p ro d u c e d in very larg e q u a n titie s, b ra ss being a c h e a p e r allo y th an a lu m in iu m b ro n z e. In c e rta in re sp ec ts, sim ilar p ro b ­ lem s are en co u n tere d . P h o s p h o r-b ro n z e die-casting is largely confined to th e p ro d u c tio n of b a rs a n d bushes in very sim ple dies, b e tte r d escrib ed as chill m oulds th a n as dies. R ecen tly , a m a te ria l of sp ecial im p o rt­

an ce in c e rta in sp h e res h a s co m e to the fo re in the fo rm of silico n b ro n z e, in w hich so m e very fine grav ity die-castings a re being m ad e. B esides the above classes o f alloys, g rav ity die-castin g s a re n o w being

Fi g. 7 .— Pr i n c i p l e o f Po u r in g Pl a t e-l i k e Ca s t i n g s ( Di a g r a m m a t i c).

k successfully made in cast iron using specialised methods.

T h e scope o f g rav ity die-casting is lim ited to the in tricacy o f castin g fro m w h ich it w o u ld be im p o s­

sible to w ith d raw the c o res a n d die b locks. F a irly in tric a te castings can be m ad e by using c o lla p sib le c o res a n d loose pieces, i.e., p a rts o f a m a in die block o r c o re w hich re m a in on the casting w hen th e die is op en ed a n d a re a fte rw a rd s picked off by h a n d . T he scope o f g ravity die-casting, h o w ev er, i,s e x p a n d e d to a lm o st u n lim ite d p ro p o rtio n s by the use o f sa n d co res w here the design o f th e castin g p ro h ib its th e use o f steel or iro n cores. T h e sa n d c o re s are, o f c o u rse only used once an d a re a fte rw a rd s re m o v e d fro m th e casting by k n o ck in g out. W h en this m eth o d is em ­ ployed, the pro cess is m o re a p tly term ed sem i-die-