These bolts have similar strength requirements but differ in their corrosion resistance. Grade B8 bolts are made from type 304 stainless steel, while Grade B8M bolts are made from a more corrosion-resistant type 316 stainless steel.
![ASTM A193](https://www.a193bolts.com/wp-content/uploads/sites/29/2016/06/header.png)
These bolts have similar strength requirements but differ in their corrosion resistance. Grade B8 bolts are made from type 304 stainless steel, while Grade B8M bolts are made from a more corrosion-resistant type 316 stainless steel.