EXTRA THICK GRADE 8 SAE FLAT WASHERS are manufactured DOMESTICALLY from medium carbon steel, through hardened (quenched and tempered) to R/C 38-45, and electro zinc plated. They are generally used in extreme heavy duty applications with high strength ASTM A325, A490, and Grade 8 bolts and nuts.
They can be as much as 50% thicker than standard Grade 8 through hardened washers.
