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Fastener Identification Markings and Bolt Strength Requirements
Download a print version| Grade Marking | Specification | Material and Treatment | Nominal Size (In.) | Mechanical Properties | Hardness Rockwell | |||
|---|---|---|---|---|---|---|---|---|
| Proof Load Min (ksi) |
Yield Strength Min (ksi) |
Tensile Strength Min (ksi) |
Min | Max | ||||
 |
SAE J429 Grade 1 |
Low or Medium Carbon Steel | ¼" - 1½" | 33 | 36 | 60 | B70 | B100 |
 |
A307 Grade A |
¼" - 4" | - | - | 60 | B69 | B100 | |
 |
A307 Grade B |
- | - | 60 min 100 max |
B69 | B95 | ||
 One End Green |
A307 Grade C *Replaced see note 8. |
- | 36 | 58 min 80 max |
- | - | ||
 One End Blue |
F1554 Grade 36 |
- | 36 | 58 min 80 max |
- | - | ||
 One End Yellow |
F1554 Grade 55 |
- | 55 | 75 min 95 max |
- | - | ||
|
|
SAE J429 Grade 2 |
¼" - ¾" ⅞" - 1½" |
55 33 |
57 36 |
74 60 |
B80 B70 |
B100 B100 |
|
 |
A193/A320 Grade B8 |
AISI SS304 Stainless | No Restrictions | - | 30 | 75 | - | B96 |
 |
A193/A320 Grade B8M |
AISI SS316 Stainless Steel | ||||||
 |
A325 Type 1 |
Medium Carbon Steel, Q & T | ½" - 1" 1⅛" - 1½" |
85 74 |
92 81 |
120 105 |
C24 C19 |
C35 C31 |
 |
A325 Type 3 |
Atmospheric Corrosion Resistant Steel, Q & T |
||||||
 |
SAE J429 Grade 5 |
Medium Carbon Steel, Q & T | ¼" - 1" 1⅛" - 1½" |
85 74 |
92 81 |
120 105 |
C25 C19 |
C34 C30 |
 |
A449 Type 1 |
¼" - 1" 1⅛" - 1½" 1⅝" - 3" |
85 74 55 |
92 81 58 |
120 105 90 |
C25 C19 B91 |
C34 C30 B100 |
|
 |
A193 Grade B7 |
Medium Carbon Alloy Steel, Q & T |
¼" - 2½" 2⅝" - 4" 4⅛" - 7" |
- | 105 95 75 |
125 115 100 |
- | C35 C35 C35 |
 |
A354 Grade BC |
¼" - 2½" 2⅝" - 4" |
105 95 |
109 94 |
125 115 |
C26 C22 |
C36 C33 |
|
 One End Red |
F1554 Grade 105 |
¼" - 3" | - | 105 | 125 min 150 max |
- | - | |
 |
A320 Grade L7 |
AISI 4140, 4142, or 4145 | ¼" - 2½" | - | 105 | 125 | - | - |
 |
A320 Grade L43 |
AISI 4340 | ¼" - 4" | - | 105 | 125 | - | - |
 |
A490 Type 1 |
Medium Carbon Alloy Steel, Q & T | ½" - 1½" | 120 | 130 | 150 min 173 max |
C33 | C38 |
 |
A490 Type 3 |
Atmospheric Corrosion Resistant Steel, Q & T |
||||||
 |
SAE J429 Grade 8 |
Medium Carbon Alloy Steel, Q & T | ¼" - 1½" | 120 | 130 | 150 | C33 | C39 |
 |
A354 Grade BD |
¼" - 2½" 2⅝" - 4" |
120 105 |
130 115 |
150 140 |
C33 C31 |
C39 C39 |
|
- All specifications are ASTM unless otherwise noted.
- All specifications shall be marked by the manufacturer with a unique identifier to identify the manufacturer or private label distributor, as appropriate.
- Q & T - Quenched and Tempered.
- Stamping of F1554 and A307 grade C bolts is a supplemental requirement while color coding is required.
- Although markings are shown on hex heads, grade markings apply equally to products with other head configurations.
- All Grade BD products shall be marked "BD". In addition to the "BD" marking, the product may be marked with 6 radial lines 60° apart.
- Hex cap screws and bolts and one end of studs shall be marked "A449". In addition, fasteners shall be permitted to be marked with three radial lines 120° apart.
- ASTM A307 grade C has been replaced by ASTM F1554 grade 36.