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ASTM A325

The ASTM A325 specification covers high strength heavy hex structural bolts from 1/2" diameter through 1 1/2" diameter. Larger bolts for structural applications are covered under ASTM A449. These bolts are intended for use in structural connections and therefore have shorter thread lengths than standard hex bolts.

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 - 1 120 92
1 1/8 - 1 1/2 105 81

Types/Recommended Hardware

Type Material Matching Nut Matching Washer
Type 1 Medium Carbon 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.