TM 1-1500-204-23-6
Table 2-1. Bolt and Screw Markings - CONT
Classification or
Marking
Material
Physical characteristics
specification
Steel, chromium
TS: 125,000 psi man up to 2-1/2
AISI 4140, 4142, and
molybdenum
inch dia inclusive
4145, grade B7
ASTM A193
TS: 115,000 psi min over 2-1/2
inch and up to 4-inch dia
inclusive
TS: 100,000 psi min over 4-inch
and up to 7-inch dia
inclusive
Steel, chromium
TS: 100,000 psi min up to 2-1/2
Grade B7M
high-molybdenum
inch dia and under
ASTM A193
TS: 115, 000 psi min over 2-1/2
inch and up to 4-inch dia
inclusive
Steel, chromium
TS: 125,000 psi min up to 2-1/2
Grade B16
molybdenum
inch dia inclusive
ASTM A193
vanadium
TS. 110,000 psi min over 2-1/2
inch and up to 4-inch dia
inclusive
TS: 100,000 psi min over 4-inch
and up to 7-inch dia
inclusive
Steel, corrosion
TS: 75,000 psi min 1/4 inch
MIL-S-1222
resistant
in dia and over
RH: B95 max
Steel, corrosion-
TS 125,000 psi min
MIL-B-6812
resistant (16Cr, 2NI)
RH C26-32
Don't temper MIL-S-18732
MIL-S-18732 (431)
(431) in the range of
NAS 380
700°F to 1000°F because
NAS 1347
of poor impact resistance
2-7
