Metric hex bolts

For help determining what grade of bolt you need see Bolt Grade Markings and Strength Chart.

Hex bolts have hexagonal heads and machine threads for use with a nut or in a tapped hole. Also known as hex cap screws or machine bolts.

Metric hex bolts

Hex bolts

A bolt with a six sided head.

Stainless steel 18-8
An alloy of steel with high corrosion resistance.
Zinc plated class 8.8 steel
A tempered medium carbon steel. Class 8.8 is hardened, but it is not as strong as class 10.9. It is commonly found in automotive applications. Class 8.8 is similar to grade 5. Zinc plated for moderate corrosion resistance.
Zinc plated class 10.9 steel
A tempered medium carbon steel. Class 10.9 is stronger than class 8.8, and is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8. Zinc plated for moderate corrosion resistance.
Chrome plated class 8.8 steel
A tempered medium carbon steel. Class 8.8 is hardened, but it is not as strong as class 10.9. It is commonly found in automotive applications. Class 8.8 is similar to grade 5. Chrome plated and polished for a mirror like finish.

A full thread bolt with a six sided head.

Stainless steel 18-8
An alloy of steel with high corrosion resistance.
Zinc plated class 8.8 steel
A tempered medium carbon steel. Class 8.8 is hardened, but it is not as strong as class 10.9. It is commonly found in automotive applications. Class 8.8 is similar to grade 5. Zinc plated for moderate corrosion resistance.
Zinc plated class 10.9 steel
A tempered medium carbon steel. Class 10.9 is stronger than class 8.8, and is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8. Zinc plated for moderate corrosion resistance.
Class 10.9 steel plain finish
A tempered medium carbon steel. Class 10.9 is stronger than class 8.8, and is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8. Unplated finish.