Cold heading Service

SAE J429 Mechanical and physical property for the different property classes of bolts, screws and studs

SAE J429 covers the mechanical and material requirements for inch series fasteners used in automotive and related industries in sizes to 1-1/2” inclusive.

Below is a basic summary of the most common grades.

GRADENominal Size, inchesFull Size Proofload, psiYield Strength, min, psiTensile Strength, min, psiElong, min, %RA, min, %Core Hardness, RockwellTempering Temperature, min
11/4 thru 1-1/233,00036,00060,0001835B7 to B100N/A
21/4 thru 3/45500057000740001835B80-B100N/A
Over 3/4 thru 1-1/233,00036,00060,0001835B70 to B100
51/4 thru 185,00092,000120,0001435C25 to C34800F
Over 1 thru 1-1/274,00081,000105,0001435C19 to C30
81/4 thru 1-1/2120,000130,000150,0001235C33 to C39800F
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.