SAE J429 Grade 8 Steel CTE Value(s)

[jlwhite]

Does anyone know the coefficient of thermal expansion (CTE) for SAE J429
Grade 8 Steel (with or without temperature dependency). I've exhausted my
resources and can't find much more than strength data.

Thanks,
Jeff

[Richard Garber]

"jlwhite" <jlw...@hiwaay.net-removethis> wrote in message
news:tgtp8rg...@corp.supernews.com...

Jeff:
The answer is roughly 12 micrometers per meter per degree Centigrade (over
20 to 100 C).
For temperature dependence over larger ranges (starting from 20 C), my
Metals Handbook gives the following values for a AISI 4140 steel:

Upper Temp, C CTE

100 12.3
200 12.7
400 13.7
600 14.5

Richard Garber

"Material furnished to you is for external use only, and may not be worth
any more than you paid for it (nothing)."

[brian whatcott]

SAE J429 is a spec for steel fasteners.
They may be made of a variety of medium carbon steel alloys.
For grade 8, the spec is for 0.28 to 0.55% carbon, quenched and
tempered to rc47 in the center of the section near the thread.
I give as an example of a permissible material, AISI 1040
details courtesy of MatWeb. I didn't take great pains to format
it beautifully, leaving it as 'an exerciuse for the interested
reader.'
Take its CTE as around 11 to 14 um per m. degC depending on the temp
range.

Brian Whatcott

THERMAL
PROPERTIES
VALUES
COMMENTS
US /
Other Units
CTE, linear 20慢,
痠/m-蚓
11.3
at 20-100蚓 (68-212蚌), 12.1
痠/m蚓 at 20-200蚓
(68-390蚌). Composition of
0.40% C, 0.11% Mn, 0.01% P,
0.03% S, 0.03% Si, 0.03% Cu.
6.3
痣n/in-蚌
CTE, linear 250慢,
痠/m-蚓
12.2
at 20-300蚓 (68-570蚌), 13.3
痠/m蚓 at 20-400蚓
(68-750蚌); Composition of
0.40% C, 0.11% Mn, 0.01% P,
0.03% S, 0.03% Si, 0.03% Cu
6.8
痣n/in-蚌
CTE, linear 500慢,
痠/m-蚓
13.9
at 20-500蚓 (68-930蚌). 14.2
痠/m蚓 at 20-600蚓
(68-1110蚌), 14.8 at
20-700蚓
(68-1290蚌); Composition of
0.40% C, 0.11% Mn, 0.01% P,
0.03% S, 0.03% Si, 0.03% Cu
7.7
痣n/in-蚌
CTE, linear 1000慢,
痠/m-蚓
14.7
Typical for steels
8.2
痣n/in-蚌
Heat Capacity,
J/g-蚓
0.486
at 50-100蚓 (122-212蚌),
0.515
J/g蚓 at 150-200蚓
(300-390蚌), 0.528 J/g蚓 at
200-250蚓 (390-480蚌), 0.548
J/g蚓 at 250-300蚓
(480-570蚌), 0.569 J/g蚓 at
300-350蚓 (570-660蚌), 0.586
J/g蚓 at 350-400蚓
(660-750蚌), 0.649 J/g蚓 at
450-500蚓 (750-930蚌), 0.708
J/g蚓 at 550-600蚓
(1020-1110蚌), 0.770 J/g蚓
at
650-700蚓 (1200-1290蚌),
1.583 J/g蚓 at 700-750蚓
(1290-1380蚌), 0.624 J/g蚓
at
750-800蚓 (1380-1470蚌).
0.12
BTU/lb-蚌
Thermal
Conductivity,
W/m-K
51.9
at 0蚓, 50.7 W/m蚓 at 100蚓
(212蚌), 48.1 W/m蚓 at 200蚓
(390蚌), 45.7 W/m蚓 at 300蚓
(570蚌), 41.7 W/m蚓 at 400蚓
(750蚌), 38.2 W/m蚓 at 500蚓
(930蚌), 33.9 W/m蚓 at 600蚓
(1110蚌), 30.1 W/m蚓 at
700蚓 (1290蚌), 24.7 W/m蚓
at 800蚓 (1470蚌), 32.9
W/m蚓 at 1000蚓 (1830蚌),
29.8 W/m蚓 at 1200蚓
(390蚌).
Brian Whatcott Altus OK
<in...@intellisys.net>
Eureka!