ASTM A490M BOLT

Description

ASTM A490M BOLT

ASTM A490M bolt specification covers two types of quenched and tempered. Alloy steel, heavy hex structural bolts having a tensile strength of 150 to 173 ksi.

A490M bolt are higher grade A325 bolt which are 120/105 minimum tensile strength steel. To minimize the risk of brittle fracture A490M bolt have both a minimum and a maximum tensile strength specified. FHWA recommends that ASTM F3125 A325M bolt be used wherever possible.

ASTM A490M and ASTM A490M are standards for heavy hex structural bolts made from alloy steel. The imperial standard for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength, while the standard (M) is titled Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for Structural Steel Joints.

ASTM A490M vs. ASTM A490

Both ASTM A490M and ASTM A490 are standards for structural bolts made from alloy steel, but they differ in specifications. The ASTM A490 standard (imperial) is titled the “Standard Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength”.

In contrast, the ASTM A490M standard (metric) is titled the “Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for Structural Steel Joints”. Both standards cover high-strength bolts, but A490M is typically used when higher strength and precise material specifications are required.

General Overview and Applications

The A490M bolt specification ensures that these bolts have a tensile strength ranging from 150 to 173 ksi, which is essential for heavy-duty structural applications. However, ASTM Standards do not allow hot dip galvanizing for corrosion protection of A490M bolts.

A490M bolts require specific zinc/aluminum coatings for corrosion resistance, making them unsuitable for hot-dip galvanization, a method commonly used for A325 bolts.

This limitation arises because the high strength of A490M bolts can be compromised during the galvanization process, potentially leading to brittle fracture in harsh environments.

These bolts are essentially equivalent to ASTM A325 bolts in terms of geometry and application but provide higher strength. The imperial grades of A490M bolts are designed to meet the same strength specifications as ASTM A354 Grade BD, while the metric grades match the specifications of ASTM F568M Property Class 10.9.

Unlike their A325 counterparts, A490M bolts are not suitable for coating methods like hot-dip galvanization, mechanical deposition, or electroplating due to their higher tensile strength.

ASTM A490M Bolt

Technical Data