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ASTM A490
The ASTM A490 specification covers alloy steel heavy hex structural bolts from 1/2" to 1-1/2" diameter. Because they are made from alloy steel, they are stronger than ASTM A325 bolts. This specification does not allow bolts to be coated by hot-dip galvanizing, or zinc plating due to the risk of hydrogen embrittlement. A type of coating called dacromet has been approved if corrosion resistance is needed.
Dimensions
| Thread Dia. |
Hex - Across Flats |
Head Height |
Thread Length |
| 1/2 | 7/8 | 5/16 | 1 |
| 5/8 | 1 1/16 | 25/64 | 1 1/4 |
| 3/4 | 1 1/4 | 15/32 | 1 3/8 |
| 7/8 | 1 7/16 | 35/64 | 1 1/2 |
| 1 | 1 5/8 | 39/64 | 1 3/4 |
| 1 1/8 | 1 13/16 | 11/16 | 2 |
| 1 1/4 | 2 | 25/32 | 2 |
| 1 3/8 | 2 3/16 | 27/32 | 2 1/4 |
| 1 1/2 | 2 3/8 | 15/16 | 2 1/4 |
Strengths
| Size | Tensile (ksi) | Yield (ksi) |
|---|
| 1/2 - 1 1/2 | 150 - 173 | 130 |
Types/Recommended Hardware
Strengths
| Type |
Material |
Matching Nut |
Matching Washer |
| Type 1 |
Alloy Steel |
A563 DH or A194 2H |
F436 |
| Type 3 |
Weathering Steel |
A563 DH3 |
F436-3 |
Connection Types
| Type |
Description |
SC |
Slip critical connection. |
| N |
Bearing type connection with threads included in the shear plane. |
| X |
Bearing-type connection with threads excluded from the shear plane. |
