Investigation of thin-walled seamless steel tubing round and streamline (Material Section report no. 133)

              AIR SERVICE INFORMATION CIRCULAR
Vol. III
<AVIATION)
PUBLISHED BY THE CHIEF OF AIR SERVICE, WASHINGTON, D. C.
July 15, 1921 No. 247
INVESTIGATION OF
THIN-WALLED SEAMLESS STEEL TUBING
ROUND AND STREAMLINE
( MATERIAL SECTION REPORT No. 133)
Prepared by Engineering Division, Air Service
McCook Field, Dayton, Ohio
March 25, 1921
WASHINGTON
GOVERNMENT PRINTING OFFICE
1921
Ralph Brown Draughon
LfBRARY
MAR 2 8 2013
Non-Depoitory
Auburn University
. .
.
f
~
"
OCH
~ ,~A ... ..q, -~.. ..
-r. '- 'o -1
INVESTIGATION OF THIN-WALLED S ~tf!SS~S 'EEL
TUBING, ROUND AND STREA~NR!·~.
PURPOSE.
To determine the minimum wall thickness which could
be obtained in seamless steel tubing; the feasibility of
manufacturing seamless streamline tubing from a circular
section; and the effect of wall thickness on local deforma­tion
or crinkling under load. ·
To check the use of Johnson's parabolic and Euler's
formulas in the design of struts made of thin-walled steel
tubing.
CONCLUSIONS.
The manufacturers of the tubing stated that after
several trials they had found that a wall thickness of
0.031 inch was the thinnest that could be manufactured
economically, and that this could not be drawn in lengths
greater than 8 feet. They also developed a method of
forming the streamline tubing from circular tubing, which
gave a very accurate cross section.
The tests indicate that the thinner gages, Nos. 19 and 21,
show more inconsistent results than the heavier gages.
An examination of the thin-walled tubing and observa­tions
made during the tests indicate that it is undesirable
to use tubing under 0.045 inch wall thickness in aircraft
construction, unless it is well braced, either internally or
externally. Tubes with thin walls are very easily dented
by careless handling, which decreases the resistance of
the tubing to column loads an indeterminate amount.
For the same slenderness ratio a round tube gives a
higher column strength than streamline tubing.
The streamline tubes are uniform in strength and for
values of the slenderness ratio above 140 the column load
follows closely the load as calculated from Euler's formula,
but is about 30 per cent lower.
Johnson's parabolic formula may be used for the design
of short columns or struts, but the yield point which is
used in this formula should be determined from the cross
section of the tubing, as the yield point in compression is
a function of the shape of the compression member. It
is found that in round tubes the yield in compression is
48,000 j:>ounds and in the streamline form is 30,000 pounds.
MATERIAL.
The material was cold-drawn, low-carbon steel tubing,
obtained from the Ohio Seamless Tube Co. and of the
analysis given below:
Carbon ... . ........... .. ... .. ........... 0.14
Manganese. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Phosphorus. .......................... . .. . 016
Sulfur.......... .. .. .. .. .................. . 049
Nickel. . ...... .. .. . ..... .. ..... .. .. .. ... Nil
Chromium ............................ . . Nil
53372-21
The thin-wall tubes were very difficult to draw and it is
practically impossible without prohibitive scrap losses
to draw a steel tube of a lighter gage than the lightest
which was made up for these tests.
The streamline tubes were made from the round tubes
of corresponding wall thickness by a simple forming opera­tion.
This was done by filling the inside of the tube
with a mobile mixture and forming in a die.
The streamline section was designed by the research
branch.
The dimensions and weights of the tubes are given in
Table I.
The dimensions for the streamline cross section are
given in figure 1.
FIG. 1.-STREAMLINE STEEL TUBE SECTION.
METHOD OF PROCEDURE.
'l'he investigation was carried out in two parts. The
first part was preliminary and consisted of tests on one
specimen of each gage thickness and cross section, making
10 specimens in all. The second part, which consisted of
tests on the remaining tubes, was carried on in practically
the same manner as the first part with few changes which
were suggested by the first group of tests.
In the first part tubes numbered 4R, 5R, 7R, lOR, 13R,
1S, 4S, · 8S, H S, and l 4S were tested.
The column tests were made on an Olsen universal
testing machine of 100,000 pounds capacity. In order to
accommodate the longer columns it was necessary to- fit
(3)
extensions to the movable head. Knife edges, fitted with
jigs for centering the tubes, were used for end bearings
for the columns. The end conditions are clearly shown
in figure 2.
4
Seven column tests were made on each tube, one at
each of the following lengths: 96, 84, 72, 60, 48, 36, and 24
inches. The load in each test was applied in each case
until the maximum was reached and then immediately
released. A check run was then made to determine
whether or not the maximum load had been reached and
also to determine to what extent, if any, the tube had
been injured.
FIG. 2.-END FITTINGS.
From each of the streamline tubes five flat tension
specimens were prepared. These were tested on an Olsen
machine. The yield point in these tests was obtained by
the drop-of-beam method.
Compression specimens, about 3 inches in length , were
cut from each tube, both round and streamline. An Ames
dial was used in these tests as a compressometer to obtain
the elastic curve.
Second part. - In this group the remaining tubes were
subjected to tests similar to those given the first group, but
in a slightly different manner. A dial was attached at the
center of each column to indicate the lateral deflection at
that point. The load-deflection data were not recorded,
the dial being used only to indicate the point at which
rapid lateral deflection began. The load at this point was
taken as the maximum column load. A check run was
made for each column in tb'.is group also.
One compression specimen was prepared from each tube.
These specimens were 7 inches in length. As in the first
group, an Ames dial was used to obtain the elastic curve.
The elastic curve was taken for the compression specimens
in order to accurately locate the elastic limit.
Tension tests were made on 10 flat specimens-two cut
from each gage thickness of the streamline tubes. A
Berry strain gage was attached to these to obtain the elas­tic
curve. On one specimen of each gage thickness the
gage was attached to the sides of the specimen and on the
other to the edge of the specimen. The results obtained
were very inconsistent, so another similar set of specimens
was prepared and an Ewing extensometer was used instead
of the Berry strain gage. This extensometer was attached
to the broad sides of the specimens in each case. This
method proved more satisfactory . The purpose of the
tension tests was to obtain, as accurately as possible, the
modulus of elasticity for use in the column formulas.
Before any tests were made on the tubes of the second
group , each tube 'was weighed and measured in order to
determine the weight per foot of each section and gage
thickness.
Several methods for computing the properties of the
cross-sections of the streamline tubes were tried, but the
one used in this report is that given in the Air Service
drafting room manual, which is as follows:
The section is carefully drawn on finely ruled cross­section
paper, the main dimension being 10 inches. It is
then divided into a number of small -trapezoidal parts and
the required properties for each of \hese calculated. By
summation, the corresponding properties of the entire
section are obtained. For any geometrically similar
figures, any one property of a section is proportional to a
certain power of one of the dimensions of the section.
RESULTS.
The results of the various tests are best shown in the
tables.
Table I gives the proper ties of the cross section and
weight per linear foot of each tube.
Table II gives the results of the tension tests on the flat
specimens cut from the streamline tubes.
Table III gives the results of the compression tests.
Table IV gives the results of the column tests. In this
table the results for both groups are given .
Figure 3 shows the results for the column tests on the
streamline tubes, along with an average curve and two
theoretical curves. One of the theoretical curves uses the
yield point obtained in the compression tests oi,.the 7-inch
specimen and the other the maximum obtained in the same
test. The section of the cuTVe to the right of the point of
tangency- that is, for values less than one-half the com­pressive
yield stress- is calculated from Euler 's formula
with round-end conditions.
Figure 4 shows the results of the column tests on the
round tubes along with an average and a theoretical curve.
The yield point in this theoretical curve is the yield point
obtained in the compression test of the 7-inch round tubes.
Figure 5 gives the average curves for both the round and
streamline tubes and the three theoretical curves which
appear in figures 3 and 4.
DISCUSSION OF RESULTS.
The column tests show that the round tubes give higher
strength values than the streamline tubes. The differ­ence
in the two strengths increases with a decrease in the
) ) )
7S
.,_ l I . r , I -~-,--------- ---------------
f-tti+t-+tt-H...J.H++-il+.f-l+fl-t14>.,-l_:~ + 1_- ~I "" I . - 1-++1:+ -+-+-.+IJ-H-+-+-+-1-+-++-+-1-.1..-1 -- - ..J:: -L :- -iJ.-:1l I I ....J I ·-H-- -H-!1'·- _·+--, _+-+-,;:_;_;_-:;.-::;_~~,;r·· ,'.= .
t-t-+++-1-+-ILl-.!-I- --r- -1 -1"'~ . 1-' , ~ .. . -f- - - . L- _LL_ ++ J_ I - I - , - ..._jl-4--JC-l-.l-.1..-f-l
t-++t-l-H--l-++-J-t-+--l-+-1-- _ _J:::,,. " I , .,_IL!-,l-+-...;.l-1-1μ_+.-++ -I
I
I
-+,.::Lr-~ I m. ~~~t ~~ ~? \~_, - -=d~+ --- -r- -- ,- -± j-
-- -~ --1 IIS- • ~ ~ ~ · - i,.; ·t · J _ _ J ,_......,._._,_......,__,-lL-.1.....:.--1-,_,
l::i-- ·j· ;·- _,, ,;;:, \ ~ .b,~ ' I' l:-+-++-+-1-+-+-++-+-+-H-l++ -1-+..+-.;.-i
I
:
I ! I
I I I
I I i
I I I : !
! : +I I I I
I ' I I
I I
""
·!-1-t--•
'
I
,,
·-+-+.++-+-1-+--+!- +4- ;.....1-
... ~ - ,_
"
I' ...
I' - -"'
"
~
....
"
"' Is.
~
'
1'
"'
COLUMN CURVES
.FDR
STn'EAMLINE TusE.s
Brolren /;~s /ndindwl Tull.rs
011/led /;ile /lrer09e Cl/rre
/ - Jt:111/l.JtJns ?ortt?bol!c r orm//kl
£ = cd, 0~ OtJtJ s y = ..]4,4()() .
..lZ-'- Jc,/;nJIJ/IS rbro/J()//c Formv/Q
£ = Z o,' 000, a:;t;7
,Sy = ..J0,000
.,. ..... I -- I ~-
........ ---IH-+-l-+++-1--1
. ""-- _. :~
.+-J-++-t+H-+++-l++-l--l--l--1-H-+-i-~--l-l-+-J--l--l-- - ·I-+-+
1
- f-aLl-·+-++-+-+-H-++-+-1-1- ·- 1- 1-;--~ -1-1-- - -· - . 1--. i- • - -'- _L.._ J....._ - ·- •• !-+-1-1·-+-l-+-++-l-t-~
.,+ l-t-+-f-+-H-+-+-+-lf-+-H-+-+-+-1-1 -f·+-+-1-+-l-a-1-1-1·-i-l-+++-+-+-H-++-1-1-1-+-++-+-+-li-+-++-+-l-+-t-+-++-+-li-+-++-+-1-+-t-+-+-l-+-l-1-+-+-l-l-+-H
I I
FIG. 3.
6
COLUMN CURVE:.:5
fOR
RouNo Tusr.s
b'ro/re/1 )')?es - .//1dY/b'ui7/ TuJe-s
Oo//ed //he -AYerc:1:7e CPrre
.zlZ - Jo,70SOl?S ,Far4bo/;C rormt/.il
f = c cJ, OOt? Oa:7.
SY= 4~000.
Jt?l?/JSO/?S ~~~#C rbrmu/n­~
,..Sy-/(/f)it
w,.,,:.,; ~re:- /r ~~ <::~
4n,E
,P: ma,,r colvm/7 $a{ I/J.
~ = c,re>a o/ cmss S~.?,?, Jf.i
l : /t'llj'l.17, h.
r • rt:1clhs p/ g-ynT//i?~ ;it
SY~CP/?l,Py~ld,IX)li;/, IPP/".Jf, ..
;~ ~ - -+-+ 1'tt-+-Ht-+--t-- Ill ,:. CO/lS/Q/1/ dep~/,¥1,.11/ . l r 0/? el?d //////7.f'.,, i/7
-+-__ t-H..,_.- · 1 1 :-~~ /l;;s cPse = 7T2
-'i---'IM-~--N-1-l I I l I ' ,;:;- . ..../. ·:\--n~~N--t-}1--' - _ +1 L. .. m~vv/u.J' ~/ e/pJ-Lf\
JUILhli_J_rF.,._?'..::l"L_~t- _1~f -:-1-!: ±JI /ICI/Y., IJ. p,r S'f', 1/1.
-•-+-,.,.,,- --- _L
j I I ' I Y\---l-+-1.-\\<cl-+_j-,."1-+- 1:· I _
,- - - , j' I
X-lf-J/-Lf-+t- -\-H''l-\'-\-i"--1: .~--""-~' ~~
F IG. 4.
)
, ,£ - .. tl
) )
t-t--+-+-+-1-+- 1-+-1---+++-+-1-11---+l+-+t l-1---+-++-t-+-l---+++--l
,-+ I ~·--t'-+-t1-t-+-t-t-t-++- t-l--1H . -+ i~l+-+~-- --<--1-+-+-+-+--1
AVERAGE AND THEORETICAL COLUMN CURVES
FOR
--"-+-H-+--t-+-+-t--t-t-+++-t--·1--t-+-+-i
+-+ -+-t-+-t-+-++-+-t-+-+-+-+-t-- +
ROUND AND 5 TREAMLINE T UBE.S
j i I f I i I . ,. ' TT·t-t--,...+-+- -t--t-+-+-+-i---i
,-,....,1.........,-+--+--+-+_-_+ -+-+--+-+·+l~ T ~ -+--1-+++-+-+ e-f+ _JI' I< ,. . , !- - - t-- - ++--j-+-+!· +-+-t-HH--t ; '
""' "" ,
....
"i1
//Yt'/'i:79'e Curn• /t?r flOt//lt:7 TvJes
1Jwr~e1 C!./ri"~ /~r S.rre'.?/77///;le 72//Jes
Jt?n/,1v01,7J PardPt?kc /ormvla, SY=- 34400
Jt:1,-1m cVi1s ? d/27.bt7.1'c rbrmvlt:I, S Y = <30000
Job !JSO/l :S PPri:?/liJ//c rb/'".mtt/d, S Y = 4<5 000
.£ 1/J I, ff c;. lff = c8oooo(}o ,
....
....
.... .... ....
....
....
'
.... ,.. ..
. ·-w--t-i- ....;'- 'e-1-+-+-++
I
' '
I
I
I
I
"" .... - 1' , ....
... f' ....
L_ " _: - - : I t -r-+-- +-_+,_-+-+ _,: :::::+-t--;·-+-<-+-+1
-+-•-+--_+-+-_+,f-_J:_-t _-_J --t-::PH--....!:_: ::Ncl-t_-++-t--f"~t-t~.._+ -f-+'kt-+--H--H-HH-+-t-t--+-+--H-++-HH-t-t+l,1 --+--
1
t-t-H+H-+++__ f -+-+-t+f1+ +-t-_+_·+.;.-_-;i.-.-.I
.-. - ., - ....
' - .... - - ~ ...
~
~ __,
1
.-.....· _ +--_r,_ ...-. _·__-,- ,-_-..,."-·+-~_-_,-++---1:_-l-f+- -...~..+ -j-+1--1'-:+ ::+'f~~+-t-1:::-+t-+t---1·~:: :--+f-+',t.:,.. :::;~-:~-:::::::::::::::::+~-:::_+::++--t--t---.i,'-+-+ -__+_+ -+,-_+-t-+- _+_+,__-++.'-.T..Jl'--H-~~lJ.~-- --~ ~=-- -,-
; ! [ I - !----j-· ~ J i f.. ! f- -
; \....." L ) i
~ - T ·-l---H-+-t-+-1t-t-++-"-'-1H-++--H-+-t-++-+1 -+-H-+-t--HH--+++;-+-t-++t-+-H--+-t--H'--i--f"t,,d-+;-J-f-'l",-._d-l-+-t-++-+-+-H-+-t--H-+-t-++-+-+-H-+-t·-+·'::1':°_-;.:+-++4'::,:_-;+-· 1 ++4
~'H' --,-+-,-t-H-+-+-+-1---++++-1-+-+-+--H~-H-++-+-1---+++--H-+-t-+-++-+-t-+-++--H-+-+-++-+-+-H-++4~-.-.~~,+. -++--Hl"ol.,t-+-H-+-t-+-+-+-+-IH- +-+-+-1----+-+-+-·t--t-+-r-+-<-+--+--+-~~
i I
I I I -
· 1+ ~ I
I + I .
- - I ..... ~ .. I .._ 1 I , f
{ l-t--+-t--+-+-+-+--t-+-+-i-+-·l-+-+--t-
++-+-1-+-+++-t-+t-t-+-t-H--+-+++-+-+-++++-H--+-+++--1-+-++++-+-t-t-+-t+--i-+-++++-+-l-++-t--H-+:'""1:-++-+-H--- . I : I , - +-i--!- I ,.... -- I + + -- -~-- --f··t'. t-1 .... -+-+--<-+--+--+-+-+-+-+-++-+-+-t-+-t--1-+-+--t-+-+-+-+-+--i--t--i--it--+--+--t-+-++-++-+-i·-+-i-+--1-+-+--t-+-+-++++-+-+- +--r+-1--H-H ....r-= - =~·;_rn'=i-l ·=+r· ~,~~ -- ~;;;:i;-,.,-~
----: :-·· ,...... - -r--~-- - -l.. .:.. 1- - -+-l-+-+-+-+--,-+-+-++-+-+-t--+-+-+-t--11---++-+-+--l-+-t-+--+-t-+-1---+++·+-,--,- +--t- - ~ - ~ - -++-+-t-t-H-~ ---~ - .. - - I- - -I- - .. - - ! I - - ~l__L ~-- - - ~-
: ; ! j ! --rr
-i---.-· ---f-1--'~ "" ..i - ..1 1=-t:!=t~i-Z,, !=l=tt:tt:t::ti~ t·t :t=tnn~-$'·.~1t:t:+::t=1r.tt:?~~""-=r.!t=-+}:::..+;1--+J-1,_=. ~.... _t,i"~": 1-+- 3i:_. ~...r.. =+--+!·1·-_:t+~_{~- ~·r,i. T--T- n =-rr_r--:1r,i-c.;.~ ·G tr.... r --.IT-T.-:.T.,l1. 1~-l~)/C:~ -v~. 1J:-:t.:. t_r..T --+-=r-::T:=.-1
:=;:;.-:;:-:::.+ ~~~:.-;_-;-.1.+t--t-+-+-+-+_... .....1..1 · -+--+-+-<-+-t--t-+-+-+-i-+-+-+-+-+_- -t--t_-+_-.+_-+--<t--+--+-1+-+-t--ir-+-·+-+-+-+-+ t-t- , . I +r.: =• -~n=- :
1-++
1
-t-t1-+-+-+++--t - •-+1-++-+-+-t-+-l++-+-1---+++-+-t-+-+-+--t--t-+--1-+-++ .s-J F/lm -- - -.~--,~ RATI /J ijr -: : I I I I
FIG. 5.
8
column lengths. No comparison can be made for the
1onger columns (slenderness ratio greater than 100), because
the round tubes were too short.
cult to get the maximum strut load of these steel tubes
without causing a slight permanent set in them. This
was somewhat eliminated in the tests of the round tubes
by placing the plane of the bend in the plane of the knife
edge, or, in other words, the longitudinal projection of the
bend would fall along the knife edges. This means that
even though the tube is bent the amount of material on
ea<;h side of the knife edges is equal. It was impossible
to do this with the streamline tubes.
The average curves for the tests check fairly well with
the theoretical formulas-Johnson's parabolic used with
Euler's formula. The discrepancies which occur between
them are probably due to errors in the test and nonuni-formity
of material. ·
The difference between the average results for the round
tubes and streamline tubes is due to the difference in the
yield point of the two when subjected to the simple com­pression
tests. As was mentioned above, in both cases
the streamline sections gave lower values than the round
sections.
In figure 5, where the two average curves are plotted along
with three theoretical curves, it is plainly seen that there
must be some difference between the yield points of the
two sections. Curve No. 1 is plotted using the maximum
load obtained in the compression tests as the compressive
yield point. This is put in for compression only, because
the curve which uses the yield point as obtained in the
compression test (No. 11) checks more closely with the
average.
The thinner gages, 0.082 and 0.042 inch, show less con­sistent
results than the thicker gages. As this is evident
for the tubes of both cross sections, it is probably due to
injury to the tube in -handling. Another reason which
may be given is the pitting of the outside surface, due to
failure to remove the scale left from the annealing process
before the final cold working. This pitting would cause a
greater percentage error on the thinner gages than it would
on the thicker gages.
In using the parabolic formula for design work, it is
suggested that the value of the yield point in compre,sion
be accmately determined by actual test of a section similar
to that which is to be used and made of the same material.
For the most part the average curves fall below the
theoretical. This is prohably due to inaccmate loading
and also may be due to the specimens being bent before
est. In regard to the latter, it was found to be very diffi-
It is also suggested that in carrying on another investi­gation
similar to this, that each tube be used for one test
only. It is thought that by the repeated use of the same
tubes the tubes \vere injured enough to affect the later
tests.
TABLE I.
PROPERTIES OF CROSS SECTION OF SEAMLESS STEEL TUBING.
Speci- Gage I Major Minor Area I Moment of Radiu~ ofl Fineness Weight
men thickness axis axis (square inertia
rrnc~!~). ratio.
per foot
No. (inches). (inches). (inches). inches). in.• (pounds).
- - - --------- ,---
1S 0. 031 3.65 l. 44 o. 2499 o. 007943 o. 5635 2.53 ··········
4S . 042 3. 64 1. 47 .3329 .009602 . 5350 2.48
8S .060 3.64 1. 45 .4695 . 013197 .5282 us 2.51 1· .... ····· .084 3. 61 1. 46 .6415 . 017683 .5229 2.47 ........ ..
14S .110 3.60 1.43 .8257 .020887 .5012 2. 52 .. · ··· ·· ··
4R .030 2.65 ---------- .2388 . 20507 .9267 5R .041 2. 65 ------·--- .3354 .28436 .9208 l 1:::::: ::::
7R . 063 2.65 ·-- ----- -- .5079 . 42392 .9132 1 . .........
lOR . 083 2.64 -- -------- .6702 . 54988 .9058 .1 ......... .
13R I .111 2.64 --- ---- -· - .8815 . 70726 .8958 1 . .... .. ...
2S .035 3. 64 1. 44 . 2762 . 00796 .5340 2. 53 0. 81
3S .032 3.65 l. 42 .2558 . 00709 .5228 2.58 . 78
58 .039 3.63 1.48 .3135 .00948 .5502 2.45 1.11
6S . 040 3.64 1. 47 .3193 .00946 .5437 2. 48 l. 08
7S .042 3.65 l. 42 .3297 .00903 . 5230 2. 58 1. 08
9S .059 3.63 1. 45 .4636 . 01310 .5262 2. 51 1. 61
10S .062 3.63 1. 45 .4852 . 01356 .5290 2.50 1. 56
12S . 083 3.61 1. 46 .6380 . 01741 .5228 2.48 2.20
13S .082 3.59 l. 48 . 6285 . 01787 . 5335 2. 43 2. 23
15S .109 3.58 l. 47 . 8165 .02193 . 5190 2.44 2. 89
16S .111 3. 61 1. 43 .824 . 02091 . 5032 2. 52 2.i,i
JR .028 2.62 · ··· ····· · .2209 .1860 .9175 1 • 71
3R .028 2. 64 --- --····· .2267 .1927 .9229 1 .93
2R .040 2. 64 ·········- .3373 . 2850 . 9192 1 1.13
6R .041 2.65 ----- ----- .3355 .2847 .9211 1 1.15 g~ I .060 2.6-1 ··· ·· ··· · · .4863 .4049 .9124 1 l.63
.064 2.63 ···· · ··- ·- .5191 . 4383 .9057 1 1. 72
llR .081 2.64 ·· ·· ···· -· .6545 .5370 .9058 1 2.24
12R .082 2.64 -----·---- .6565 .5381 . 9053 l 2. 27
14R .111 2.64 -···· · ···· .8791 . 7061 .8962 1 3.03
15R .113 2.65 ----·-- --- .9330 . 7466 .8946 1 3. 04
R-llound. S=St~eamline.
9
TABLE II.
TENSION TESTS ON FLAT SPECIMENS CUT FROM STREAMLINE STEEL TUBING.
I Stress at Ultimate
Per cent elongation in- Modulus
Spcci- \ Gage elastic stiength or elastic-men
thickness limit ity (1,000 (pounds (pounds pounds
No. I( inches). persquare per square 2 inches. 4 inches. 8 inches. pe{;~te inch). inch).
---- ---------- ---
2-1 I 0. 024 20, 730 53, 760 16. 0 13. 8 13. 0 25, 710
2-2 .027 18,560 54,260 15.5 13. 5 12.5 29,690
5-1 . 041 22.000 58, 750 19. 0 15. 3 no 27, 040
5-2 . 044 22; 770 57, 800 21. 0 16. 5 12. 4 25, 190
1()-1 .0615 29, 330 61 ,260 27.0 22. 0 16. 0 26,640
10-2 .055 32,730 62, 730 22. 5 15. 5 8.9 27,510
12-1 . 081 22,180 52, 730 29. 5 24.5 19. 4 31,130
12-2 . OR2 19,510 51. 220 34.0 27. 0 20.9 28,100
16-1 .104 21, 150 53,270 ..... i!i."ii" 31,080
16-2 .110 29, 090 50,910 24. 5 H.S 29,380
Average . ..... 23,800
55,670 \··········
28,150
Value used ... 24,000 56,000 .. . ....... 28,000
I I
N OTE.-All specimens t inch wide through gage length.
TABLE III.
COMPRESSION TESTS ON SEAMLESS STEEL TUBING.
Yield . ffitimat e l Av~rage I Average
Gage Length point yield ultunate
Speci- strength point strength
men thick- of speci- (pounds (pounds (pounds (pounds
No. ness men per per per per
(inches). (inches). square ~quare square square
inch). mch). inch). inch).
--- ------------ --- - ---- - - --
I 1S 0.031 1.9 20, 000
I
22,810 · --------- ------- ---
4S . 042 2.1 27,000 35, 740 --------- - ----------
8S . 060 2.2 21,300 40,470 --------- - -·--······
11S .084 2. 1 24,200 38,190 -·-·-···-· ··---·-·--
14S .110 2.2 25, 450 42,390 23,590 35, 920
4R .030 3.95 44,350 55,850 -·-·-···-· -- -·-·-·--
5R . 041 3. 75 43,520 56,570 -·-·-···-· ---·······
7R .063 . 3. 75 46,290 54,780 -·-·····-· ------··· ·
JOR .083 3. 75 68,020 78,070 ---------· -·-·······
13R .111 3. 93 64,430 76,390 53,320 64,330
2S . 035 7 18, 100 21, 720 -········· -·· · ·· · · ··
3S .032 7 19,940 21,500 -------- -- ---------·
5S .039 7 34,770 38,280 -····· ···· ..........
6S .040 7 32,570 36,000 ---·-·-· -· - · - ··· · ···
7S .042 7 33, 670 36,400 --······· · --- ····· ·· 9S . 059 7 33,870 35, 160 ······· ··· --··· ··· · ·
10S .062 7 31,530 36,690 ·· ·· -----· ····· ·····
12S . 083 7 29,470 34,480 · ······--· ··-···· ··-
13S .082 7 31,500 35,960 .......... -···-----· 15S .109 7 31,840 40,420 ······-··- -··------- '
16S .111 7 30, 100 41,260 29,760 34,350
lR .028 7 27,160 30, 780 -- ------- . ····-----· 3R . 028 7 44,110 58,400 - ·· -·· · ·· - ···--·-·-·
2R .040 7 53,360 52,930 ·· ··-···-- -------- --
6R .041 7 44,710 52, 160 ·········· ··········
8R .060 7 41,190 53,030 ---· -----· -· -···· ···
9R .064 7 43,150 59, 720 ----- -··· - -·····- ···
HR . 081 7 61, 120 77,160 -········ - - -·-· · · ·· ·
12R .082 7 54,840 69,310 ········· - ·········-
14R . 111 7 58,240 77,920 1-·:is;3iio· · ••.••••••• 1
15R .113 7 55, 730 70, 740 60,220 I
10
TABLE IV.
RESULTS OF COLUMN TESTS ON SEAMLESS STEEL TUBING, ROUND AND STREAMLINE.
Speci- Length, 96 Length, 84 Length, 72 Length, 60 Length, 48 men inches, inches, inches, inches, inches, Length, I inc3h6e s
No. 1/r. PIA. ljr. P/A. l/r. P/A. 1/r. P/A. 1/r. P/A. ljr. P/A.'
-------------- --- - - ----- - --- - --- - - - --- ---
1S 170. 4 7,620 149.1 11,520 127. 8 11,810 106. 5 ---- --- --- S.S. 2 17, 290 63.9 19,050
4S 179. 4 7,470 157. 0 9, 840 134. 6 12,880 112.1 19,170 89. 7 25,970 67. 3 -- ------ - 8S 181. 7 6, 560 159. 0 8, 470 136.3 9,980 113.6 16,090 90. 9 2-3,310 68. 2 -- ----- -- 118 183.6 6,920 160. 6 8, 690 137. 7 11,300 114. 7 16,890 91. 8 18, 950 68. 8 22, 410
14S 191. 5 6, 8.50 167. 6 8, 820 143. 7 9, 360 119. 7 15,130 95. 8 17, 640 71.8 22,580
4R 103.6 23,610 90.6 26, 330 77. 7 31, 570 64. 7 44, 460 51. 8 55,900 38. 8 ---- ----- 5R 104. 3 24,120 91.2 24,390 78. 2 31,390 65.2 43.560 52.1 47,280 39.1 48,060
7R i~:i I 23,090 92. 0 27,520 78. 8 34,760 65. 7 39, 020 52. 6 41,550 39. 4 48, 030
lOR 25, 220 92. 7 30,550 79. 5 33,360 66. 2 51,440 53.0 48, 220 39. 7 62,600
13R 107. 2 26,810 93.4 32, 310 80.4 39,480 67. 0 48, 530 53. 6 59, 460 40. 2 66,850
2S 179. 8 6, 390 157. 3 7,060 134. 8 10, 170 112. 4 14,480 89. 9 15, 790 67. 4 .. . ... . ..
3S 183. 6 6, 330 160. 6 ---------- 137. 7 --------- - 114. 7 --··· · ··-· 91. 8 ----- --·-· 68. 8 ·· · ······ 5S 174. 5 8, 330 152. 7 9,090 130. 9 13, 400 109.1 19, 140 87. 2 23, 350 65.4 . ........
6S 176. 6 7,360 154. 5 ·· ·- · · -·· · 132. 4 . 6, 107 110. 4 10,300 88. 3 . . . . ...... 66.2 23,490
7S 183. 6 7,080 160. 6 7, 460 137. 7 12, 740 114. 7 19,110 91.8 ........ . . 68. 8 ·· · ····-- 9S 182. 4 7, 230 159. 6 8, 000 136. 8 13, 720 114. 0 20, 990 91.2 25,450 68. 4 28, 800
10S 181. 5 6,740 158. 8 6, 000 136.1 12, 780 113. 4 17, 520 90. 7 22, 820 68.1 25, 540
12S 183. 6
7,260 I I O 7
6.290 I Vl7. 7 12, 510 114.8 16,220 91. 8 19, 670 68.9 27,590
13S 179. 9 7,700 157. 5 6, 460 135. 0 11, 220 112. 5 18,930 90. 0 22,780 67. 5 34, 210
15S 185. 0 7,800 161. 8 8, 550 138. 7 10, 960 115. 6 13,990 92. 5 18, 270 69.4 24, 540
16S 190. 7 8,620 166. 9 4, 900 143. 1 8,800 119. 2 14,680 95.4 19, 440 71. 6 26, 080
IR 104. 6 19,690 91.6 ---------- 78. 5 ··· · ·----- 65. 4 ---------- 52. 3 -·-·-·---· 39. 3 27, 840
3R 104. 0 22, 940 91. 0 27,220 78. 0 33, 080 65. 0 37,410 52. 0 39,260 39.0 44, 110
2R 104. 4 24, 760 91. 4 28, 760 78. 3 29 350 65.3 34,890 52. 2 40,740 39. 2 46, 400
6R 104. 2 25,340 91. 2 27, 420 78. 2 33; 980 65.1 33,530 52. 1 36,360 39. 1 44,500
SR 105. 2 17,420 91. l 20 560 78. 9 22,000 65.8 28,400 52. 6 33, 8.50 39. 5 37, 570
9R 106.0 21,310 92. 7 22; 960 79. 5 32,440 66. 2 34, 710 53.0 42, 090 39. 7 34, 680
UR 106.0 25, 030 92. 7 31, 260 79. 5 37, 740 66.2 43, 8.50 53.0 48, 130 39. 8 53,710
12R 106. 0 23,400 92. 8 20,430 79. 5 34,990 66. 3 41,430 53.0 43,950 39. 8 52,640
14R 107. 1 25,230 93. 7 26, 470 80. 3 31, 230 66. 9 32,190 53.6 42,660 40.2 54,410
15R 107. 3 21,650 93. 9 24, 270 80. 5 28,560 67. 1 30,920 53. 7 37, 940 40. 3 45,100
I
0
L en gth,
ljr.
--- ·
42. 6
44. 9
45. 4
45. 9
47. 9
25. 9
26. 1
26. 3
26.5
26.8
44.9
45.9
43.6
44. 1
45. 9
45. 6
45. 4
45. 9
45.0
46. 3
47. 7
26. 2
26. 0
26. 1
26.1
26. 3
26. 5
26. 5
26. 5
26. 7
26.9
24
inches,
P/A.
- - -
23,910
35,990
37, 530
24,400
24,650
62,590
50,410
49,290
74,930
68,910
21, 540
21, 110
32,060
19, 100
35,030
33,050
33,940
31,660
··· ·· ·· · - 30, 800
29,130
30, 2
47,2
52,4
40
00
80
00
60
0
47,4
42,2
43, 77
62,34 0
0
0
80
53, 85
56,61
51, 5
V
-
~----