Fastener Identification Markings
A practical guide to common bolt, rod, stud, and fastener grade markings used to identify material specifications and mechanical strength requirements.
Identification Table
Showing 24 of 24 fastener marking records.
| Marking | Specification | Material / Treatment | Nominal Size | Proof Load Min ksi | Yield Min ksi | Tensile Min ksi | Notes |
|---|---|---|---|---|---|---|---|
SAE J429 Grade 1
|
SAE J429 Grade 1 | Low or medium carbon steel | 1/4" - 1-1/2" | 33 | 36 | 60 | No grade mark. General low-strength carbon steel fastener grade. |
ASTM A307 Grade A
|
ASTM A307 Grade A | Low or medium carbon steel | 1/4" - 4" | - | - | 60 | Common low carbon steel bolt specification. |
ASTM A307 Grade B
|
ASTM A307 Grade B | Low or medium carbon steel | 1/4" - 4" | - | - | 60 min / 100 max | Used where A307 Grade B is specifically required. |
ASTM A307 Grade C
|
ASTM A307 Grade C | Low or medium carbon steel | 1/4" - 4" | - | 36 | 58 min / 80 max | One end green. Replaced by ASTM F1554 Grade 36. |
ASTM F1554 Grade 36
|
ASTM F1554 Grade 36 | Low or medium carbon steel | 1/2" - 4" | - | 36 | 58 min / 80 max | One end blue. Anchor bolts / anchor rods. |
ASTM F1554 Grade 55
|
ASTM F1554 Grade 55 | Low or medium carbon steel | 1/2" - 4" | - | 55 | 75 min / 95 max | One end yellow. Anchor bolts / anchor rods. |
ASTM F1554 Grade 105
|
ASTM F1554 Grade 105 | Medium carbon alloy steel, quenched and tempered | 1/2" - 3" | - | 105 | 125 min / 150 max | One end red. High-strength anchor bolts / anchor rods. |
ASTM A193 / A320 Grade B8 Class 1
|
ASTM A193 / A320 Grade B8 Class 1 | AISI 304 stainless steel | No restriction | - | 30 | 75 | Stainless steel bolting. |
ASTM A193 / A320 Grade B8 Class 2
|
ASTM A193 / A320 Grade B8 Class 2 | AISI 304 stainless steel, strain hardened | Up to 1-1/2" | - | Varies by size | 100 - 125 | Higher strength stainless bolting. |
ASTM A193 / A320 Grade B8M Class 1
|
ASTM A193 / A320 Grade B8M Class 1 | AISI 316 stainless steel | No restriction | - | 30 | 75 | 316 stainless steel bolting. |
ASTM A193 / A320 Grade B8M Class 2
|
ASTM A193 / A320 Grade B8M Class 2 | AISI 316 stainless steel, strain hardened | Up to 1-1/2" | - | Varies by size | 90 - 110 | Higher strength 316 stainless bolting. |
ASTM F3125 Grade A325 Type 1
|
ASTM F3125 Grade A325 Type 1 | Medium carbon steel, quenched and tempered | 1/2" - 1-1/2" | 85 | 92 | 120 | Structural bolt assembly. A325 is now under ASTM F3125. |
ASTM F3125 Grade A325 Type 3
|
ASTM F3125 Grade A325 Type 3 | Atmospheric corrosion resistant steel, quenched and tempered | 1/2" - 1-1/2" | 85 | 92 | 120 | Weathering steel structural bolt assembly. |
SAE J429 Grade 5
|
SAE J429 Grade 5 | Medium carbon steel, quenched and tempered | 1/4" - 1-1/2" | 85 / 74 | 92 / 81 | 120 / 105 | Three radial lines. Common Grade 5 cap screw / bolt marking. |
ASTM A449 Type 1
|
ASTM A449 Type 1 | Medium carbon steel, quenched and tempered | 1/4" - 3" | 85 / 74 / 55 | 92 / 81 / 58 | 120 / 105 / 90 | Often used for larger diameter headed bolts and rods. |
ASTM A449 Type 3
|
ASTM A449 Type 3 | Weathering steel, quenched and tempered | 1/4" - 3" | 85 / 74 / 55 | 92 / 81 / 58 | 120 / 105 / 90 | Weathering steel version of A449. |
ASTM A193 Grade B7
|
ASTM A193 Grade B7 | Medium carbon alloy steel, quenched and tempered | 1/4" - 7" | - | 75 - 105 | 100 - 125 | Common high-temperature/high-pressure bolting grade. |
ASTM A354 Grade BC
|
ASTM A354 Grade BC | Medium carbon alloy steel, quenched and tempered | 1/4" and larger | 105 / 95 | 109 / 99 | 125 / 115 | Alloy steel bolt, stud, and threaded fastener grade. |
ASTM A320 Grade L7
|
ASTM A320 Grade L7 | AISI 4140, 4142, or 4145 | 1/4" - 2-1/2" | - | 105 | 125 | Low-temperature bolting grade. |
ASTM A320 Grade L43
|
ASTM A320 Grade L43 | AISI 4340 | 1/4" - 4" | - | 105 | 125 | Low-temperature alloy bolting grade. |
ASTM F3125 Grade A490 Type 1
|
ASTM F3125 Grade A490 Type 1 | Medium carbon alloy steel, quenched and tempered | 1/2" - 1-1/2" | 120 | 130 | 150 min / 173 max | High-strength structural bolt assembly. A490 is now under ASTM F3125. |
ASTM F3125 Grade A490 Type 3
|
ASTM F3125 Grade A490 Type 3 | Atmospheric corrosion resistant steel, quenched and tempered | 1/2" - 1-1/2" | 120 | 130 | 150 min / 173 max | Weathering steel high-strength structural bolt assembly. |
SAE J429 Grade 8
|
SAE J429 Grade 8 | Medium carbon alloy steel, quenched and tempered | 1/4" - 1-1/2" | 120 | 130 | 150 | Six radial lines. Common Grade 8 cap screw / bolt marking. |
ASTM A354 Grade BD
|
ASTM A354 Grade BD | Medium carbon alloy steel, quenched and tempered | 1/4" - 4" | - | 130 | 150 min / 173 max | Grade BD products must be marked BD; radial lines may also appear. |
Need Help Identifying a Fastener?
Send the marking, diameter, length, finish, and project specification to Lord & Sons and we can help identify the correct requirement.