STANDARD BOLT IDENTIFICATION MARKINGS

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Proof Load(psi)Yield StrengthMin (psi)Tensile StrengthMin (psi)Low or Medium Carbon Steel1/4 THRU 1 33,00036,000Low CarbonSteel1 4 thru 4 SAE J429Grade 2Low or Medium Carbon Steel1 4 thru 3 4Over 3 4 thru 1 55,00033,00057,00036,00074,00060,000 No Grade MarkSAE J429Grade 4StudsMedium Carbon Cold Drawn Steel1 4 thru 1 100,000115,000Low or Medium Carbon Steel1/4 THRU 1 33,00036,000Low CarbonSteel1 4 thru 4 Low or Medium Carbon Steel1 4 thru 3 4Over 3 4 thru 1 55,00033,00057,00036,00074,00060,000ASTM A193Grade B5Bolts, Screws, Studs forHigh Temperature ServiceAISI 5011 4 thru 4 80,000100,000ASTM A193Grade B6Bolts, Screws, Studs forHigh Temperature ServiceAISI 4101 4 thru 4 85,000110,000ASTM A193Grade B7Bolts, Screws, Studs forHigh Temperature ServiceAISI 4140,4142.

High‐ Temperature Service ASTM A193 Grade B6 Bolts, Screws, Studs for High‐ Temperature Service ASTM A193 Grade B7 Bolts, Screws, Studs for High‐ Temperature Service AISI 4140, 4142, or 4145 1⁄4 thru 2 ½ Over 2 ½ thru 4 Over 4 thru 7 −− −− −− 105,000 …

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