STS Industrial - Bolts & Screws

 

A307 GRADE A HEX HEAD BOLTS

GOVERNING STANDARDS:
ASTM A307 Grade A Covers the mechanical and material requirements for inch series fasteners in diameters from 1/4″ through 4″, made of carbon steel having a minimum tensile strength of 60,000 psi. 
ASME B18.2.1 Covers the complete general and dimensional data for multiple types of inch series square and hex bolts and screws.
ASME B1.1 UNC & UNF Class 2A Specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads.

 

APPLICATIONS:

Common / economical fastener used for general applications.

ASTM A307 Grade A Head Marking

Product to be marked with the manufacturers head marking as indicated by the X.

MATERIAL PROPERTIES:
Low Carbon Steel

GRADE

DIAMETER

BOLT OR STUD LENGTH

TENSILE STRENGTH

MIN ELONG IN 2”

CORE HARDNESS

Grade A 1/4 through 4” Less than 3 X diaA 60,000 psi Min 18% B69 to B100
3 X dia and Longer 60,000 psi Min 18% B100
Required hardness applies to measurements taken anywhere on the surface or through the cross section. Core hardness listed is Maximum acceptable unless a range is specified.

Also bolts with drilled or undersized heads. These sizes and bolts with modified heads shall meet the minimum and maximum hardness as hardness is the only requirement.

 

  • SIMILAR GRADES

    SAE J429 Grade 2

    Metric Class 4.6

  • RECOMMENDED NUTS

    ASTM A563 Grade A

DIMENSIONAL SPECIFICATIONS:

ASTM A307 Hex Head Bolt Dimensions

Usable thread length for A307 Grade A Hex Head Bolts can be approximated by the equation    THREAD LENGTH = (2 X DIAMETER) + 1/4″

Sources: ASTM Standards for Mechanical Fasteners and Related Processes 2nd Edition, Inch Fastener Standards 8th Edition, Kanebridge Fastener Reference Guide 4th Edition

Note: All material included on this page is informational only, and should not be used as one’s sole source for design purposes. STS Industrial, Inc. and its affiliates do not guarantee the accuracy of the information on this site, and retain no liability for the use or misuse of the information contained on this site.