BIG BOLT NUT is an ISO 9001 certified company and has been manufacturing bolts and nuts in stainless steel, carbon steel and alloy steel since 1989. We manufacture bigger diameter bolts and nuts from M-20 till M-72 and in inches and Unc from 3/4" to 3" and we are specialist manufacturers for stainless steel bolts and nuts in SS 304, SS 316, SS 316L and 316S31 grade for the marine, water and sewage treatment industry.