Fastener Identification Markings
Fastener Identification Markings

Fastener Identification Markings


No Markings Bolt Head
NO MARKINGS
No Markings Bolt Head
NO MARKINGS
SpecificationSAE J429
Grade 1
SAE J429
Grade 2
MaterialLow or Medium Carbon SteelLow or Medium Carbon Steel
Nominal Sizes1/4” through 1-1/2”1/4” through 3/4”over 3/4” through 1-1/2”
Proof Load Stress33 ksi55 ksi33 ksi
Min. Tensile Strength60 ksi74 ksi60 ksi
Min. Hardness RockwellB70B80B70
Max. Hardness RockwellB100B100B100


No Markings Bolt Head
307A
No Markings Bolt Head
307B
SpecificationASTM A307
Grade A
ASTM A307
Grade B
MaterialLow or Medium Carbon SteelLow or Medium Carbon Steel
Nominal Sizes1/4” through 4”1/4” through 4”
Proof Load Stress--
Min. Tensile Strength60 ksi60 ksi min.
100 ksi max.
Min. Hardness RockwellB69B69
Max. Hardness RockwellB100B95


3 Line Bolt Head
THREE LINES
3 Line Bolt Head
THREE LINES
SpecificationSAE J429
Grade 5
ASTM A449
Type 1
MaterialMedium Carbon Steel Quenched and TemperedMedium Carbon Steel Quenched and Tempered
Nominal Sizes1/4” through 1”over 1 through 1-1/2”1/4” through 1”over 1 through 1-1/2”
Proof Load Stress85 ksi74 ksi85 ksi74 ksi
Min. Tensile Strength120 ksi105 ksi120 ksi105 ksi
Min. Hardness RockwellC25C19C25C19
Max. Hardness RockwellC34C30C34C30


6 Line Bolt Head
SIX LINES
6 Line Bolt Head
SIX LINES
SpecificationSAE J429
Grade 8
ASTM A354
Grade BD
MaterialMedium Carbon Alloy Steel Quenched and TemperedMedium Carbon Alloy Steel Quenched and Tempered
Nominal Sizes1/4” through 1-1/2”1/4” through 1-1/2”over 2-1/2” through 4”
Proof Load Stress120 ksi120 ksi105 ksi
Min. Tensile Strength150 ksi150 ksi140 ksi
Min. Hardness RockwellC33C33C33
Max. Hardness RockwellC39C39C39


A325 Bolt Head
A325
3 Lines - A325 Bolt Head
THREE LINES & A325
SpecificationASTM A325
Type 1
ASTM A325
Type 2
MaterialMedium Carbon Steel, Quenched and TemperedLow Carbon Martensite Steel, Quenched and Tempered
Nominal Sizes1/2” through 1”over 1 through 1-1/2”1/2” through 1”over 1 through 1-1/2”
Proof Load Stress85 ksi74 ksi85 ksi74 ksi
Min. Tensile Strength120 ksi105 ksi120 ksi105 ksi
Min. Hardness RockwellC24C19C24C19
Max. Hardness RockwellC35C31C35C31


A490 Bolt Head
A490
A490 Underlined Bolt Head
A490 UNDERLINED
6 Lines - A490 Bolt Head
SIX LINES & A490
SpecificationASTM A490
Type 1
ASTM A490
Type 2
ASTM A490
Type 3
MaterialMedium Carbon Alloy Steel, Quenched and TemperedLow Carbon Martensite Steel, Quenched and TemperedAtmospheric Corrosion Resistant Steel, Quenched and Tempered
Nominal Sizes1/2” through 1-1/2”1/2” through 1”1/2” through 1-1/2”
Proof Load Stress120 ksi120 ksi120 ksi
Tensile Strength150 ksi Min.
170 ksi Max.
150 ksi Min.
170 ksi Max.
150 ksi Min.
170 ksi Max.
Min. Hardness RockwellC33C33C33
Max. Hardness RockwellC38C38C38


Please Note:
The above specifications are offered as a guide ONLY. Specifications should be determined with assembly conditions taken into account.



Last Updated: Sep 17, 2019
Update History:
Sep 17, 2019 by bbasile from Calgary Fasteners
Jun 18, 2019 by jsjohnson from Calgary Fasteners
Jun 18, 2019 by jsjohnson from Calgary Fasteners
Dec 12, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners