Bolt standard ASTM A490

ASTM A490 Covers heavy hex bolts also known as structural bolts made of alloy steel with minimum 150 ksi strength.

ASTM A490 bolts are designed for building structures and usually are partially threaded with a shank longer than standard hex bolts. ASTM A490 standard bolts are very closed in structure and application to A325, However they have higher tensile and strength. This standard of hex bolts should not be processed for hot deep galvanization to avoid hydrogen embrittlement. Therefore, in case of requirement for coating Dacromet coating is recommended.

Mechanical properties of ASTM A490 bolts are as follows:

Size in	Tensile ksi	Proof load ksi	Elongation %
1/2 - 1 1/2	min 150-173	130	14

Four different types of ASTM A490 standard bolts are manufactured

Type 1	Alloy steel or medium carbon steel
Type 2	Withdrawn since 2002
Type 3	Weathering steel
M	A490 Metric standard

Also, this standard of bolts require special standard of nuts and washers that are in the table below:

NUT		WASHER
Type 1	Type 3	type 1	Type 3
A563DH	A563DH3	F436-1	F436-3

Bolt and nut