STS Industrial - Bolts & Screws

SAE J429 HEX HEAD CAP SCREWS


SCOPE:

SAE J429 covers the mechanical and material requirements for inch series fasteners used in automotive and related industries in diameters through 1-1/2″. The summary below covers the most common grades. SAE J429 also covers a number of less common grades including 1, 4, 5.1, 5.2, 8.1, and 8.2.

SAE J429 Grade 2 Hex Head Bolt and Cap Screw Head Marking

SAE J429 Grade 2

No grade mark. Manufacturer’s head marking as denoted by the X.

SAE J429 Grade 5 Hex Head Bolt and Cap Screw Head Marking

SAE J429 Grade 5

3 radial lines 120 degrees apart. Manufacturer’s head marking as denoted by the X.

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

SAE J429 Grade 8

6 radial lines 60 degrees apart. Manufacturer’s head marking as denoted by the X.

MATERIAL PROPERTIES:

GRADE

DIAMETER

FULL SIZE PROOF LOAD

MIN YIELD STRENGTH

MIN TENSILE STRENGTH

MIN ELONG

MIN REDUCTION AREA

CORE HARDNESS

1 1/4″ through 1-1/2″

33,000 psi

36,000 psi 60,000 psi 18% 35%

B7 to B100

2 1/4″ through 3/4″

55,000 psi

57,000 psi 74,000 psi 18% 35%

B80 to B100

7/8″ through 1-1/2″

33,000 psi

36,000 psi 60,000 psi 18% 35%

B70 to B100

5 1/4″ through 1″

85,000 psi

92,000 psi 120,000 psi 14% 35%

C25 to C34

1-1/8″ through 1-1/2″

74,000 psi

81,000 psi 105,000 psi 14% 35%

C19 to C30

8

1/4″ through 1-1/2″

120,000 psi

130,000 psi 150,000 psi 12% 35%

C33 to C39

 Grade 2 requirements for sizes 1/4″ thru 3/4″ apply only to bolts 6″ and shorter, and to studs of all lengths. For bolts longer than 6″, Grade 1 requirements shall apply.

Sources: ASTM Standards for Mechanical Fasteners and Related Processes 2nd Edition, Inch Fastener Standards 8th 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.