United A irlin e s
C urtis A ir P ow ered H oists pro v id e faster, m ore a c c u ra te lift
ing, a n d ca n be o p e ra te d by m en o r w om en, skilled o r unskilled.
T h e y are im m u n e to d a m a g e from overloads a n d a re av ailab le in capacities u p to 10 tons — p e n d a n t o r b rack eted types.
F o r in fo rm atio n as to how C u rtis air-o p e ra te d e q u ip m e n t can speed p ro d u ctio n , low er costs in y o u r p la n t, w rite for B ulletin A-4-B.
U n ite d A irlines rem oves d ir t a n d grease from e n gine p a rts by d ip p in g in to a v at of clean in g fluid on a g ra te d floor tra y . T h e raisin g a n d low ering o p era tio n is co n tro lled by a C U R T I S A ir H o is t, as i l l u s t r a t e d . T h e u se o f s u c h c le a n in g tra y s has resulted in m a n -h o u r sav
ings of as m u ch as 30% . H ere is a n o th e r e x am p le of the savings in tim e a n d la b o r th a t you, too, ca n achieve th ro u g h using C u rtis A ir H oists o r C ylinders for p rac tic ally any push, pull, or lifting problem.
168 / T E E L
B
e h i n d t h e g r o w i n g p r e f e r e n c e fo r A M P tu b e s is tw e n ty -e ig h t y ears’ e x p e rie n ce in m a k in g electric- resistan ce w e ld e d steel tu b in g , tu b u la r p a rts a n d assem blies.W e m a n u f a c t u r e s te e l tu b es u p to o u tsid e d im en sio n s o f 5 Vi inches a n d w ith w a ll th ic k n e ss u p to 5 /l6 - in c h . T h e y can b e fo rg ed , u p se t, sw aged,
e x p a n d e d , f o r m e d , h e a t - t r e a t e d , m a c h in e d o r w e ld e d in a n y d esired m a n n e r. W e h av e th e m o st m o d e rn fa c ilitie s to d o a ll these th in g s in p r o d u c tio n q u a n titie s.
Let u s c o n su lt w ith y o u a b o u t y o u r tu b in g p ro b lem s. P o ssib ly w e can save y o u tim e an d m o n ey —a n d im p ro v e th e p e rfo rm a n c e o f y o u r p ro d u c t!
A M E R I C A N M E T A L P R O D U C T S C O M P A N Y
5 9 5 9 Linsdale Avenue, Detroit 4 , Michigan
May 7. 1945
M X BRONZES • MONEE METAE
* AEEOY IRONS
total power going into the chips re
mained constant for all the diiferent cutter angles which were investigated.
This type of test excludes errors due to motor and gear variations. T he most valuable characteristic of this method, is the consistency with which test re
sults can be duplicated within close limits at any time. It is possible to- study the effects of workpiece m ater
ials, feeds, speeds, and tool angles, on the power requirem ents of the tool and the tem perature of the chips by noting the tem perature change of the w ater into which th e chips fall.
N et horsepower expended on th e chips is the mechanical equivalent of the heat increase in tire calorimeter per unit time.
Therefore N et lip =
( A T ) (W ater equivalent)
T
O D A Y you can n am e any' n u m b e r o f in sta n c e s w h e re life its e lf d e p e n d s u p o n th e re lia b ility o f in d iv id u a l e n g in e o r m a c h in e ry p a rts. In a irc ra ft fo r in sta n c e . A nd th a t’s o n e re a s o n w hy so m any le a d in g e n g in e an d m a c h in e ry b u ild e rs a re sp e cify in g S h e n a n g o -P e n n c e n trifu g a l c a stin g s . . . b ecau se th e se c a stin g s d efinitely offer s u p e rio r s tre n g th a n d d u ra b ility .T h e re a so n is sim p le. T u b u la r p a rts c a st by S h e n a n g o - P e n n ’s c e n trifu g a l p ro c e ss h av e g re a te r d en sity , -m ore u n ifo rm g r a in stru c tu re , h ig h e r te n sile s tre n g th , b e tte r e lo n g a tio n , n o b lo w h o le s , less p o ro sity . T h u s they a re b e tte r a b le to w ith sta n d sh o c k a n d a ll k in d s o f p u n ish m e n t, an d they w e a r lo n g e r.
So if you re q u ire tu b u la r o r r in g p a rts th a t m ust not p a rt, S h e n a n g o -P e n n ca stin g s a re th e best k in d o f in su ra n c e . B u lletin 143 g iv es c o m p le te d ata in c lu d in g co st-sa v in g p r o d u c tio n a d v a n ta g es, allo y sp e cific atio n s, p h y sic al an d c h e m ic a l p ro p e rtie s , etc.
W rite to S h e n a n g o - P e n n M o ld C om pany, 457 W . T h ird Street, D over, O h io .
f T E E L
The circu la r p a r ts shown above w ere cast cen trifu gally by Shenango-Penn in tu bu lar shapes a n d then cut off to precise thickness. AH m achining a n d fin ish in g operations in clu d in g d r illin g w e re also p e rfo rm e d in the Shenango-Penn shops where the m ost m odern m achine tools a r e a va ila b le to tu rn out com pletely fin ished p a rts if d esired .
D ata Bu lletin 143 is yours free for the a sk in g .
(C utting time, m in.) (42.44 B tu/m in) where
A T = Calorimeter tem perature rise °F.
1 lip = 42.44 B tu/m in
In these particular tests the cut was 1 inch long, the cutting time, therefore, could be expressed as the reciprocal of the feed rate F in inches per m inute or 1/F . The w ater equivalent for the calorimeter, steel chips, and w ater was 0.2452 pound. Then
N et hp = ( A T ) (0.2452) ( 1 /F ) . (42.44)
From the product of the temperature rise of the calorimeter and the w eight of w ater plus the w ater equivalent of the calorimeter, the quantity of heat given off by the chips was determined.
Before the chips fell into the water this quantity of heat existed in these chips alone. It was therefore possible to compute the maximum average chip tem perature by the process of therm al balance commonly used in calorimet- ric tests.
( A T c ) (chip w t) (sp h t) — ( A T ) (W ater equivalent of cal
orimeter, chips and w ater) where A T c = average tem perature
rise of chips, °F A T = tem perature rise in
calorimeter, °F The change of specific heat of the steel with increasing -tem peratures was not taken into account in the above for
mula. W ith the specific heat values of gamma iron, a corrected average chip tem perature value was com puted for cutting tests in which the testbar ma
terial was SAE-1055.
W ith this equipm ent several thou
sand tests were run and the resulting information perm itted a mathematical analysis of th e face milling process at both low and high cutting speeds.
Since it was recognized th at the horsepower consumption was affected chiefly by th e radial rake angle, the test cutters were m ade identical ex
cept for this angle which was varied from 30 degrees negative to 30 degrees positive™. It was found th at the power required at the cutting edge is higher