ENQUIRY

aSTM A 193

Chemical Composition for Stainless steel bolts & nuts

Grade of alloy steel for Stud-Bolts to BS 1750 , ASTM A 193 and A 320
1 SYMBOL                               B7                   B7M                  B16 B8 B8M B8T L7 / L7M L43
2 Type Ferritic Ferritic Austenitic Austenitic
Unstabilized
Asutenitic Austenitic
Stabilized
Ferritic Ferritic
3 Service conditions High Temp. High Temp. High Temp. High Low.
Temp.
High Low.
Temp.
High Low.
Temp.
Low Temp. Low Temp.
4 Material specification
5 ASTM A193
Grade B7
A193
Grade B7M
A193
Gr. B16
A193
Grade B8
A193
Grade B8M
A193
Grade B8T
A320
Grade L7
A320
GradeL43
Chemical composition % % % % % % % %
6 C. 0.37---0.49 0.37---0.49 0.36---0.47 0.08 max. 0.08 max. 0.08 max. 0.38---0.48 0.38---0.43
Mn. 0.65---1.10 0.65---1.10 0.45---0.70 2.00 max. 2.00 max. 2.00 max. 0.75---1.00 0.60---0.85
Si. 0.15---0.35 0.15---0.35 0.15---0.35 1.00 max. 1.00 max. 1.00 max. 0.15---0.35 0.15---0.35
P. 0.035 max. 0.035 max. 0.035 max. 0.045 max. 0.045 max. 0.045 max. 0.035 max. 0.040 max.
S. 0.04 max. 0.04 max. 0.04 max. 0.030 max. 0.030 max. 0.030 max. 0.040 max. 0.040 max.
Cr. 0.75---1.20 0.75---120 0.80---1.15 18.00---20.00 16.00---18.00 17.00---9.00 0.80---1.10 0.70---0.90
Ni. ---     --- ---     --- ---    --- 8.00---10.50 10.00---14.00 9.00---12.00 ---    --- 1.65---2.00
Mo. 0.15---0.25 0.15---0.25 0.50---0.65 ---    --- 2.00---3.00 ---     --- 0.15-0.25 0.20---0.30
V. ---     --- ---    --- 0.25---0.35 ---    --- ---    --- ---     --- ---    --- ---     ---
Ti. ---     --- ---    --- ---     --- ---    --- ---    --- 5xCMIN ---    --- ---     ---
Brinell Hardness Not
applicable
max. 20 RC Not
applicable
223 B.H.N.
max.
223 B.H.N.
max.
223 B.H.N.
max.
Not
applicable
Not
applicable
7 Impact Value Not
applicable
Not
applicable
Not
applicable
Not
applicable
Not
applicable
Not
applicable
20 ft. lbf.
at 1500 F
20 ft. lbf.
1500F min
8 Physicalas per ASTM A 193 & B.S. 1506-621 & B.S. 4882.
9 U.T.S. 88kg/MM2min 70.3 min. 88kg/MM2min 52.75/MM2min 52.75kg/MM2 52.75kg/MM2 88kg/MM2 88kg/MM2
Elongation 16% min 18% min 18% min 30% min 30% min 30% min 16% min 16% min
Yield 70.39kg/MM2 56.26 min. 73.8kg/MM2 21.1kg/MM2min 21.1kg/MM2 21.1kg/MM2 73.8kg/MM2 73.8kg/MM2
Reduction area 50% min 50% min 50% min 50% min 50% min 50% min 50% min 50% min
Heat treatment Oil quenched
& tempered
Oil quenched
& tempered
Oil quenched
& tempered
Carbide solution
treated
Carbide solution
treated
Carbide solution
treated
Oil quenched
& tempered
Oil quenched
& tempered
10 Tempering temperature 11000F min 5930C 11500F min 6200C 12000F min 6500C ---      --- ---     --- ---    --- 11000F min 5930C min 11000F min 5930C min