ASME B18.2.6M

Metric Fasteners for Use in Structural Applications

This Standard covers the complete general and dimensional data for products in the metric series recognized as American National Standard for sizes M12 through M36. These four metric structural products include

(a)  Metric heavy hex structural bolts: ASTM A325 Mand ASTM A490M

(b)  Metric heavy hex nuts: ASTM A563M

(c)  Metric hardened steel washers; circular, circular clipped, and bevelled: ASTM F436M

(d)  Metric compressible washer-type direct tension indicators: ASTM F959M

1.1.2 The inclusion of dimensional data in this Standard is not intended to imply that all products described herein are stock production sizes. Consumers should consult with suppliers concerning lists of available stock production sizes.

Bolt Materials and Processing

Chemical and mechanical properties of steel bolts shall conform to ASTM A325M or ASTM A490M as applicable.

Nut Materials

Chemical and mechanical properties of heavy hex nuts shall conform to ASTM A563M property classes.

Washer Materials and Mechanical Properties

Materials and properties shall conform to the requirements specified in ASTM F436M.


Each bolt shall be marked in accordance with the requirements of the applicable specification, ASTM A325M or ASTM A490M.