Hex Bolt Identification, Markings and Strength Chart Table Guide

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Hex Bolt Identification, Markings and Strength Chart Table Guide

Hex Bolt Identification, Markings and Strength Chart. Additonal information on bolts is located at the bottom of the webpage.

Note: Some bolts share identical head identification and have significantly different strengths.

Identification
Grade Mark
Specification Description Material Proof Load Yield Strength
Min (psi)
Tensile Strength
Min (psi)
astma449.gif (1118 bytes) SAE J429
Grade 5

ASTM A449
Bolts, Screws,
Studs
Medium Carbon Steel 85,000
74,000
92,000
thru 81,000
120,000
thru 105,000
saej429.gif (1143 bytes) SAE J429
Grade 5.1
Sems Low or Medium Carbon Steel 85,000 - 120,000
saej42~1.gif (1162 bytes) SAE J429
Grade 5.2
Bolts,
Screws,
Studs
Low Carbon 85,000 92,000 120,000
astma3~1.gif (983 bytes) ASTM A325
Type 1
High Strength
Structural Bolts
Medium Carbon 85,000
74,000
92,000
thru 81,000
120,000
thru 105,000
astma325.gif (1251 bytes) ASTM A325
Type 2
High Strength
Structural Bolts
Low Carbon 85,000 92,000 120,000
astma3~2.gif (1086 bytes) ASTM A325
Type 3
High Strength
Structural Bolts
Corrion Resistant
Steel
85,000
74,000
92,000
81,000
120,000
105,000
astma3~4.gif (1038 bytes) ASTM A354
Grade BB
Bolts, Studs Alloy Steel 80,000
75,000
83,000
78,000
105,000
100,000
astma33.gif (1042 bytes) ASTM A354
Grade BC
Bolts, Studs Alloy Steel 105,000
95,000
109,000
99,000
125,000
115,000
saej42~2.gif (1298 bytes) SAE J429
Grade 7
Bolts, Screws Medium Carbon Alloy Steel 105,000 115,000 133,000
saej42~3.gif (1346 bytes) SAE J429
Grade 8
Bolts, Screws,
Studs
Medium Carbon Alloy Steel 120,000 130,000 150,000
saej42~3.gif (1346 bytes) ASTM A354
Grade BD
Bolts, Screws,
Studs
Alloy Steel 120,000 130,000 150,000
saej42~4.gif (2382 bytes) SAE J429
Grade 8.1
Studs Medium Carbon Steel 120,000 130,000 150,000
astma490.gif (1161 bytes) ASTM A490 Structural Bolts Alloy Steel 120,000 130,000 150,000
thru 170,000
saej42~4.gif (2382 bytes) ISO R898
Class 4.6
Bolts, Screws, Studs Low or Median Steel 33,000 36,000 60,000
saej42~4.gif (2382 bytes) ISO R898
Class 5.8
Bolts, Screws, Studs Low or Median Steel 55,000 57,000 74,000
isor89~1.gif (1050 bytes) ISO R898
Class 8.8
Bolts, Screws, Studs  Median Steel 85,000 92,000 120,000
isor89~2.gif (1042 bytes) ISO R898
Class 8.8
Bolts, Screws, Studs  Median Steel 85,000 92,000 120,000
isor89~3.gif (1072 bytes) ISO R898
Class 10.9
Bolts, Screws, Studs Alloy Steel 120,000 130,000 150,000
isor89~4.gif (1073 bytes) ISO R898
Class 10.9
Bolts, Screws, Studs Alloy Steel 120,000 130,000 150,000
astma~20.gif (1186 bytes) ASTM A320
Grade B8
Bolts, Screws, Studs AISI 304 - 30,000 75,000
astma~21.gif (1321 bytes) ASTM A320
Grade B8C
Bolts, Screws, Studs AISI 347 - 30,000 75,000
astma~11.gif (1102 bytes) ASTM A320
Grade B8T
Bolts, Screws, Studs AISI 321 - 30,000 75,000
astma3~8.gif (1096 bytes) ASTM A320
Grade B8F
Bolts, Screws, Studs AISI 303
or 303Se
- 30,000 75,000
astma~22.gif (1094 bytes) ASTM A320
Grade B8F
Bolts, Screws, Studs AISI 316 - 30,000 75,000
astma~10.gif (958 bytes) ASTM A320
Grade B8
Bolts, Screws, Studs AISI 304 - 50,000
Thru 100,000
105,000
Thru 125,000
astma~13.gif (1173 bytes) ASTM A320
Grade B8C
Bolts, Screws, Studs AISI 347 - 50,000
Thru 100,000
105,000
Thru 125,000
astma~12.gif (1109 bytes) ASTM A320
Grade B8F
Bolts, Screws, Studs AISI 303
or 303Se
- 50,000
Thru 100,000
105,000
Thru 125,000
astma1~4.gif (1074 bytes) ASTM A320
Grade B8M
Bolts, Screws, Studs AISI 316 - 50,000
Thru 100,000
105,000
Thru 125,000
astma~14.gif (1124 bytes) ASTM A320
Grade B8T
Bolts, Screws, Studs AISI 321 - 50,000
Thru 100,000
105,000
Thru 125,000
astma1~1.gif (1047 bytes) ASTM A193
Grade B8T
Bolts, Screws, Studs AISI 321 30,000 75,000
astma~10.gif (958 bytes) ASTM A193
Grade B8
Bolts, Screws, Studs AISI 304 - 50,000
thru 100,000
100,000
thru 125,000
astma~13.gif (1173 bytes) ASTM A193
Grade B8C
Bolts, Screws, Studs AISI 347 - 50,000
thru 100,000
100,000
thru 125,000
astma1~4.gif (1074 bytes) ASTM A193
Grade B8M
Bolts, Screws, Studs AISI 316 - 50,000
thru 95,000
90,000
thru 125,000
astma~14.gif (1124 bytes) ASTM A193
Grade B8T
Bolts, Screws, Studs AISI - 50,000
thru 95,000
100,000
thru 120,000
saej42~4.gif (2382 bytes) SAE J429
Grade 1
Bolts, Screws, Studs Low or Median Carbon Steel 33,000 36,000 60,000
astma~17.gif (1144 bytes) ASTM A320
Grade L7B
Bolts, Screws, Studs,
Low temp Appl.
AISI 4137 - 105,000 125,000
astma~18.gif (1202 bytes) ASTM A320
Grade L7C
Bolts, Screws, Studs,
Low temp Appl.
AISI 8740 - 105,000 125,000
  • Tensile Strength: The maximum load in tension (pulling apart) which a material can withstand before breaking or fracturing.
  • Yield Strength: The maximum load at which a material exhibits a specific permanent deformation
  • Proof Load: An axial tensile load which the product must withstand without evidence of any permanent set.
  • 1MPa = 1N/mm2 = 145 pounds/inch2