Q: Am I correct in my understanding that 304SS (UNS S30400) can be sold as “18-8” hardware – but that not all 18-8 hardware is necessarily (UNS S30400)?
A: 304 stainless steel fits into a general category of stainless steel that is referred to as “18-8”. However, if you buy 18-8 hardware, it may not be 304. The term 18-8 stainless steel refers to many specific varieties of 300 series stainless, including: 302, 302HQ, 303, 304, 316. Many times, smaller 18-8 screws are made from 302HQ which is used often in cold heading. So, if you need specifically 304SS, you should specify 304SS so that we provide the correct material. If you specify 18-8, it could be made from 302, 302HQ, 303, 304, or 316 stainless steels.