| Grade Marking |
Spec. | Material | Bolt & Screw Size |
Proof Load PSI |
Tensile Strength Min PSI |
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SAE-Grade 1 | Low Carbon Steel | 1/4" - 1-1/2" | 33,000 | 60,000 |
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ASTM-A307 | Low Carbon Steel | 1/4" - 1/2" 1-1/2" - 4" |
33,000 | 60,000 55,000 |
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SAE-Grade 2 | Low Carbon Steel | 1/4" - 3/4" 3/4" - 1-1/2" |
55,000 33,000 |
74,000 60,000 |
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SAE-Grade 3 | Medium Carbon Steel, Cold Worked |
1/4" - 1-1/2" 1/2" - 5/8" |
85,000 80,000 |
110,000 100,000 |
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SAE-Grade 5 ASTM-A 449 |
Medium Carbon Steel, Quenched & Tempered |
1/4" - 1" Over 1" - 1-1/2" Over 1-1/2" - 3" |
85,000 74,000 55,000 |
120,000 105,000 090,000 |
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ASTM-A 325 | Medium Carbon Steel, Quenched & Tempered |
1/2", 5/8", 3/4" 7/8", 1" 1-1/8" - 1-1/2" |
85,000 78,000 74,000 |
120,000 115,000 105,000 |
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ASTM-A 354 Grade BB |
Low
Alloy Steel, Quenched & Tempered |
1/4" - 2-1/2" Over 2-1/2" - 4" |
80,000 75,000 |
105,000 100,000 |
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ASTM-A 354 Grade BC |
Low
Alloy Steel, Quenched & Tempered |
1/4" - 2-1/2" Over 2-1/2" -4" |
105,000 095,000 |
125,000 115,000 |
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SAE-Grade 5.1 | Low
or Medium Carbon Steel, Quenched & Tempered, with Assembled Lock Washer |
Up to 3/8" incl. | 85,000 | 120,000 |
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SAE-Grade 7 |
Quenched & Tempered, Roll Threaded after Heat Treatment |
1/4" - 1-1/2" | 105,000 | 133,000 |
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SAE-Grade 8 | Medium Carbon Alloy Steel, Quenched & Tempered |
1/4" - 1-1/2" | 120,000 | 150,000 |
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ASTM-A 354 Grade BD |
Alloy Steel, Quenched & Tempered |
1/4" - 1-1/2" | 120,000 | 150,000 |
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ASTM-A 490 | Alloy Steel, Quenched & Tempered |
1/2" - 2-1/2" Over 2-1/2" - 4" |
120,000 105,000 |
150,000 140,000 |