Stainless Steel Bolt Head Markings 1

[Carburize]

On a set of bolts the heads are marked 304SS ( Grade 304 stainless steel)- "THE" What does the "THE" represent and can the strength grade of the fasteners be determined from the inforamtion on the head?

 

[Paskenell]

These bolts were manufactured by Tong Hwei Enterprises of either Malaysia, China, or most likely, Taiwan. As to the 304SS specification the bolts are marked to show they were made from 304 stainless steel. You will need to obtain proper material certification from the distributor to ensure this. Otherwise, the parts can legally be represented as 18-8 stainless steel.

As to your question in reference to "strength grade", commercial stainless steel does not come in grades, as does steel. There are many places on the net mis-representing 304 stainless bolts as a grade 5 or grade 8 strength equivalent, but 304 stainless does NOT meet these strength specs. If you need certified strength stainless steel bolts, I would suggest you examine the specs for an ASTM A193-B8 bolt. If your application does not require strength above commercial level, these parts should work well.

David Long
Marine Fasteners