Often times we find ourselves in the hardware store searching for a new bolt to match an old rusted one, the one we broke, or just because we want a new shiny one. The following charts can be used to help find what you need.
Tips for Hex Bolts:
Bolt length measurements are made without the head.
Grade 5 Standard (SAE & USS) and Metric 10.9 bolts are the best choices for automotive
applications. The Grade 8 bolt is a high strength bolt but harder, and more likely to snap in the wrong application.
A Grade 5 bolt will have 3 radial lines on the bolt head.
A Grade 5 hex nut will have 3 dots on it's face edge.
Stainless steel bolts have the same approximate strength as the Grade 5 bolt. They shouldn't
rust and are also used in marine applications. The markings vary.
Metric 10.9 bolts have the same strength as the Grade 8 bolt. Ford used the 10.9 bolt
throughout the Mustang.
The 10.9 Metric bolt is approximately 30% stronger than the Grade 5 bolt, and the 10.9
lettering will be stamped on the head of the bolt.