Standar for Bolt

Grade

Bolt Size

Tension Stength

Yield Strength

Enlogation

Reduction of Area

Hardness

Head Marking

in.

ksi

ksi

min%

min%

Brinell

Rockwell

A193/A193M

B5

to 4

100min

80min

16

50

/

/

B6

to 4

110min

85min

15

50

/

/

B6X

to 4

90min

70min

16

50

/

C26

B7

to 2-1/2

125min

105min

16

50

/

C35

over 2-1/2 to 4

115min

95min

16

50

over 4 to 7

100min

75min

18

50

B7M

to 4

100min

80min

18

50

235

B99

over 4 to 7

100min

75min

18

50

235

B99

Class 1:
B8,B8M,B8P,

all

75min

30min

30

50

223

B96

B16

to 2-1/2

125min

105min

18

50

321

C35

over 2-1/2 to 4

110min

95min

17

45

321

C35

over 4 to 7

100min

85min

16

45

321

C35

Class 2:B8M

to 3/4

110min

96min

15

45

321

C35

over 3/4 to 1

120min

80min

20

45

321

C35

over 1 to 1-1/4

110min

95min

25

45

321

C35

over 1-1/4 to 1-1/2

100min

85min

30

45

321

C35

Grade and Class

Diameter in.

Tensile Strength ksi

Yield Strength 0.2% Offset ksl

Elongation in 4D min, %

Reduction of Area min, %

Hardness Max

Min

Min

Min

Min

Brinell

Rockwell

B7

TO 2-1/2

125

105

16

50

C35

over 2-1/2 to 4

115

95

16

50

C35

over 4 to 7

100

75

18

50

C35

B7M

to 4 incl.

100

80

18

50

235

B99

over 4 to 7

100

75

18

50

235

B99

B16

TO 2-1/2

125

105

18

50

321

C35

over 2-1/2 to 4

110

95

17

45

321

C35

over 4 to 7

100

85

16

45

321

C35

Class 2:B8M, B8MN

to 3/4

110

96

15

45

321

C35

over 3/4 to 1 incl.

100

80

20

45

321

C35

over 1 to 1-1/4 incl.

95

65

25

45

321

C35

over 1-1/4 to 1-1/2 incl.

90

50

30

45

321

C35

ldentification
Symbol. . .

B7, B7M

B16

Grade . . .

Chromium-Molybdenum (C 4140, 4142, 4145, 4140 H, 4142 H, and 4145 H)

Chromium.Molybdenum-Vanadium

Range

Product Variation, Over or Under

Range

Product Variation, Over or Under

Carbon

0.37 - 0.49

0.02

0.36 - 0.44

0.02

Manganese

0.65- 1.10

0.04

0.45 - 0.70

0.03

Phosphorus, max

0.035

0.005 over

0.035

0.005 over

Sulfur, max

0.04

0.005 over

0.040

0.005 over

Silicon

0.15- 0.35

0.02

0.15 - 0.35

0.02

Chromium

0.75- 1.20

0.05

0.80- 1.15

0.05

Molybdenum

0.15 - 0.25

0.02

0.50 - 0.65

0.03

Vanadium

0.25 - 0.35

0.03

Aluminum, max%

0.015