Our highest tensile of Imperial Bolts is our Grade 9 or L9 range. Previously known as FX180. Yellow Zinc finish. The L9 Grade 9 fastening range has a tensile strength of 180,000psi.
Grade 9 Bolt dimensions are exactly the same as that of Grade 8 bolts except the head height.
The head height of the Grade 9 Bolt is slightly higher than other bolts, for better wrenching.
Head height (in thou) = Max 0.706 & Min 0.670
Thread = 8 TPI Hexagon Across the Flats ( AF ) = 1 1/2"