19 rows US Bolts: Head Marking Grade and Material Nominal Size Range (inches) Mechanical Properties ; Proof Load (psi) Min. Yield Strength (psi) Min. Tensile Strength Standards for bolt strength grades are set according to a system devised by the Society of Automotive Engineers; this marking system uses raised dashes on the bolt head to indicate strength. Other systems use raised numerals on the bolt head to indicate bolt grade. marking, all grades, except A563 grades O, A and B, must be marked for manufacturer identification. The markings shown for all grades of A194 nuts are for cold formed and hot forged nuts. When nuts are machined from bar stock the nut must be additionally marked with the letter ‘B’.

Lubricated Bolts and Reduced Torque - Lubrication effect on bolt tension and torque Metric Bolts - Head and Wrench Sizes - ANSI/SO, DIN and JIS bolts Metric Steel Bolts - Grades and Property Classes - Metric steel bolts, screws and studs - proof and tensile strength Determining Bolt Grades Understanding Head Markings The Nut and Bolt Solution Series. Identifying bolt grades and head markings for US grades 2, 5 and 8. Metric grades 8.8.,10.9 and 12.9 (socket products). Video 1: Determining Bolt Grade and Head Markings Technical Reference Guide Table of Contents Subject Page # Fastener Material Selection 1 Mechanical Properties . specifications that require impact testing on certain grades. Materials Carbon Steel . ASTM A307 Grade B is a special low carbon steel grade of bolt used in piping and flange

Steel Bolts - Metric Grades Steel Bolts - SAE Grades For metric bolts strength is according ISO 898 Mechanical properties of fasteners made of carbon steel and alloy steel described by property classes with designations 4.6, 4.8, 5.8, 8.8, 9.8, 10.9 and 12.9.