ASTM A307-21 - 15.2.2021
 
1. Scope

1.1?This specification2 covers the chemical and mechanical requirements of two grades of carbon steel bolts and studs in sizes 1/4?in. through 4 in. The fasteners are designated by Grade denoting tensile strength and intended use, as follows:

Grade

Description

?

Grade A

Bolts, studs, and threaded rod having a minimum tensile strength of 60 ksi and intended for general applications,

Grade B

Bolts, studs, and threaded rodA having a tensile strength of 60 to 100 ksi and intended for flanged joints in piping systems with cast iron flanges, and

Grade C

Replaced by Specification F1554 Gr.36

1.2?This specification does not cover requirements for machine screws, thread cutting/forming screws, mechanical expansion anchors or similar externally threaded fasteners.

1.3?Suitable nuts are covered in Specification A563. Unless otherwise specified, the grade and style of nut for each grade of fastener, of all surface finishes, shall be as follows:

Fastener Grade and Size

Nut Grade and StyleA

A 1/4?to 11/2?in.

A, hex

A over 11/2?to 4 in.

A, heavy hex

B, 1/4?to 4 in.

A, heavy hex

1.4?The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

1.5?Supplementary Requirement S1 of an optional nature is provided, which describes additional restrictions to be applied when bolts are to be welded. It shall apply only when specified in the inquiry, order, and contract.

1.6?Terms used in this specification are defined in Terminology F1789 unless otherwise defined herein.

1.7?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

B?18.24

Part Identifying Number (PIN) Code System Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http://www.asme.org.

F1470-24

Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection

F788/F788M-20e1

Standard Specification for Surface Discontinuities of Bolts, Screws, Studs, and Rivets, Inch and Metric Series (Includes all amendments and changes 9/12/2023).

F606-14

Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets

B695-21

Standard Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel

A751-21

Standard Test Methods and Practices for Chemical Analysis of Steel Products

A706/A706M-22a

Standard Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete Reinforcement (Includes all amendments and changes 2/22/2023).

A563-15

Standard Specification for Carbon and Alloy Steel Nuts

B18.31.3

Threaded Rods (Inch Series)

F2329-13

Standard Specification for Zinc Coating, Hot-Dip, Requirements for Application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners

B?1.1

Unified Screw Threads Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.

B?18.2.1

Square and Hex Bolts and Screws

F1554-20

Standard Specification for Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength

F1789-23

Standard Terminology for F16 Mechanical Fasteners