Identification Markings on Bolt Heads
ASTM and SAE Standards
| GRADE MARKING |
SPEC. | MATERIAL | BOLT & SCREW SIZE |
PROOF LOAD PSI |
TENSILE STRENGTH MIN. PSI |
 |
SAE-Grade 1 | Low Carbon Steel | 1/4" thru 1-1/2" | 33,000 | 60,000 |
|
|
ASTM-A307 | Low Carbon Steel | 1/4" thru 1-1/2" Over 1-1/2"-4" |
33,000 | 60,000 55,000 |
|
|
SAE-Grade 2 | Low Carbon Steel | 1/4"thru 3/4" Over 3/4" - 1-1/2" |
55,000 33,000 |
74,000 60,000 |
 |
SAE-Grade 3 | Medium Carbon Steel, Cold Worked |
1/4"thru 1-1/2" Over 1/2" - 5/8" |
85,000 80,000 |
110,000 100,000 |
 |
SAE-Grade 5 ASTM-A 449 |
Medium Carbon Steel, Quenched and Tempered |
1/4"thru 1" Over 1" - 1-1/2" 1/4" thru 1" Over 1" - 1-1/2" Over 1-1/2" - 3" |
85,000 74,000 85,000 74,000 55,000 |
120,000 105,000 120,000 105,000 90,000 |
 |
ASTM-A 325 | Medium
Carbon Steel, Quenched and Tempered |
1/2",
5/8", 3/4" 7/8", 1" 1-1/8" thru 1-1/2" |
85,000 78,000 74,000 |
120,000 115,000 105,000 |
 |
ASTM-A
354 Grade BB |
Low
Alloy Steel, Quenched and Tempered |
1/4"
thru 2-1/2" Over 2-1/2" - 4" |
80,000 75,000 |
105,000 100,000 |
 |
ASTM-A
354 Grade BC |
Low
Alloy Steel, Quenched & Tempered |
1/4"
thru 2-1/2" Over 2-1/2" - 4" |
105,000 95,000 |
125,000 115,000 |
 |
SAE-Grade 5.1 | Low
or Medium Carbon Steel, Quenched & Tempered, with Assembled Lock Washer |
Up to 3/8" incl. | 85,000 | 120,000 |
 |
SAE-Grade 7 | Medium
Carbon Alloy Steel, Quenched and Tempered, Roll Threaded after Heat Treatment |
1/4" thru 1-1/2" | 105,000 | 133,000 |
 |
SAE-Grade 8 | Medium
Carbon Alloy Steel, Quenched & Tempered |
1/4" thru 1-1/2" | 120,000 | 150,000 |
|
|
ASTM-A
354 Grade BD |
Alloy
Steel, Quenched & Tempered |
1/4" thru 1-1/2" | 120,000 | 150,000 |
 |
ASTM-A 490 | Alloy
Steel, Quenched & Tempered |
1/2"
thru 2-1/2" Over 2-1/2" - 4" |
120,000 105,000 |
150,000 140,000 |