This specification2 covers two types of quenched and tempered@ steel@ metric heavy hex structural bolts having a minimum tensile strength of 830 MPa (Note 1). The bolts are intended for use in structural connections. These connections are comparable to those covered under the requirements of the Specification for Structural Joints using ASTM A 325 or A 490 bolts@ approved by the Research Council on Structural Connections; endorsed by the American Institute of Steel Construction and by the Industrial Fastener Institute.3 The bolts are furnished in sizes M12 to M136 inclusive. They are designated by type denoting chemical composition as follows: Type1 - Medium-carbon@ carbon boron@ medium carbon alloy@ or alloy boron steel. Type 2-Withdrawn in 2003. Type 3-Weathering Steel. This specification is applicable to metric heavy hex@ structural bolts only. Terms used in this specification are defined in Terminology F 1789. The following safety hazard caveat pertains only to the test methods portion@ Section 10@ of this specification. This standard does not purport to address all of the safety concerns@ if any@ associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. NOTE 1- This specification is the metric companion to the inch pound Specification A 325. 2 For ASME Boiler and Pressure Vessel Code applications@ see related Specification SA-325M in Section II of that Code. 3 Available from American Institute of Steel Construction (AISC)@ One E. Wacker Dr.@ Suite 3100@ Chicago. IL 60601-2001. * A Summary of Changes section appears at the end of this standard.