Torque Ratings for Grade 5 and Grade 8 Fasteners

To determine what fastener is right for the job, you must be able to identify what grade fastener and torque rating you are using. Fasteners are graded by tensile strength and are easily identified by the number of slash marks on the head of the fastener. Torque is measured in foot pounds.

  • Grade 5 fasteners have 3 lines or markings on the head resembling the shape of a “Y"
  • Grade 8 fasteners have 6 lines or markings on the head as displayed in the figure below

 

THREAD SIZESAE GRADE 575% YIELD STRENGTH (PSI) =69000SAE GRADE 875% YIELD STRENGTH (PSI) = 98000
PLAINFt. Lbs.ZINC PLATEDFt. Lbs.PLAINFt. Lbs.ZINC PLATEDFt. Lbs.
1/4 - 209101314
1/4 - 2810121516
5/16 - 1819212729
5/16 - 2421233033
3/8 - 1633374752
3/8 - 2438425459
7/16 - 1453597683
7/16 - 2460668593
1/2 - 138290116127
1/2 - 2092101131144
9/16 - 12118129167184
9/16 - 18131144186205
5/8 - 11162179231254
5/8 - 14184202261287
3/4 - 10288317409450
3/4 - 16322354457503