SAE & ASTM Bolt Grade Identification Marks
and Mechanical Properties 
Bolt Grade Identification Marking Specs Nominal Size
(inch)
Proof Load Stress
(ksi)
Tensile Strength
(min ksi)

Material
Notes

SAE J429 - Grade 5 SAE – Grade 5 1/4 thru 1 85 120 2, b
ASTM A449 – Type 1 1 1/8  thru 1-1/2 74 105
1 3/4 thru 3 55 90
ASTM A325 - Type 1 ASTM A325 – Type 1 1/2 thru 1 85 120 2, b
1 1/8 to 1-1/2 74 105
ASTM A325 - Type 3 ASTM A325 – Type 2 1/2 thru 1 85 120 4,b
1 1/8 to 1-1/2 74 105
ASTM A325 - Type 3 ASTM A325 – Type 3 1/2 thru 1 85 120 5,b
1 1/8 to 1-1/2 74 105
ASTM A354 - Grade BC ASTM A354 – Grade BC 1/4 thru 2-1/2 105 125 5,b
2-3/4 thru 4 95 115
SAE Grade 7 1/4 to 1 1/2 105 133 7,b
SAE J429 - Grade 8 SAE – Grade 8 1/4 thru 1-1/2 120 150 7,b
ASTM A354 – Grade BD 1/4 thru 1-1/2 120 150 6,b
SAE J429 - Grade 8.2 SAE – Grade 8.2 1/4 thru 1 120 150 4,b
ASTM A490 - Type 1 ASTM A490 – Type 1 1/2 thru 1-1/2 120 150 6,b
ASTM A490 - Type 3 ASTM A490 – Type 3 1/2 thru 1-1/2 120 150 5,b

Material Notes

  1. Low or Medium Carbon Steel
  2. Medium Carbon Steel
  3. Low Carbon
  4. Low Carbon Martensite
  5. Weathering Steel 
  6. Alloy Steel
  7. Medium Carbon Alloy 

Treatment – 

a – cold drawn
b – quenched and tempered

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