In 2016 ASTM international replaced the standards A325, A325M,

A490, A490M, F1852 and F2280 with the new standard F3125.

A325 and A490 heavy hex structural bolts are now grades

under the new F3125 specification.

ASTM F3125 Unified Structural Bolt Specifications

This harmonised standard is to ensure alignment between standards with the same intended end use and to simplify the use and maintenance of structural bolt specifications for all users.


The 6 ASTM Standards include:

ASTM A325 Structural Bolt Imperial

ASTM A325M Structural Bolt Metric

ASTM A490 Structural Bolt Imperial

ASTM A490M Structural Bolt Metric

ASTM F1852 Tension Control Assembly

ASTM F2280 Tension Control Assembly

Bolts are designated by grade or property class which indicates inch or metric respectively, type symbolising raw material chemical composition and by style symbolising Heavy Hex bolts or Twist Off style.

ASTM Nut & Washer Specifications

ASTM A563 Heavy Hex
Nut Imperial or Metric

ASTM F436 Hardened Washer Imperial or Metric

ASTM F959 DTI Washer Imperial or Metric

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