STS Industrial - Bolts & Screws

 

SAE J429 GRADE 8 HEX HEAD CAP SCREWS

GOVERNING STANDARDS:
SAE J429 Covers the mechanical and material requirements for inch series fasteners used in automotive and related industries in diameters through 1-1/2″.
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 high strength fastener. Has greater tensile strength than Grade 5. Designed for use in high stress applications.

SAE J429 Grade 8 Hex Head Bolt and Cap Screw Head Marking

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

MATERIAL PROPERTIES:
Medium Carbon Alloy Steel, Heat Treated, Quenched and Tempered

Note: For diameters 1/4″ through 7/16″, it is permissible to use AISI 1541 steel.

DIAMETER

PROOF LOAD

YIELD STRENGTH

TENSILE STRENGTH

CORE HARDNESS

1/4″ through 1-1/2″ 120,000 psi 130,000 psi 150,000 psi C33 to C39
Elongation 12% Minimum (All Diameters)
Reduction of Area 35% Minimum (All Diameters)
Material strengths listed are minimum acceptable per governing standard. Core hardness based on Rockwell scale. For diameters larger than 1-1/2 in., see  ASTM A354 Grade BD.

 

DIMENSIONAL SPECIFICATIONS:

SAE J429 Grade 8 Hex Head Cap Screw Dimensions

Usable thread length for Grade 8 Hex Head Cap Screws 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.