Execution standard reference

Stainless Steel Stainless Steel Mushroom head square neck bolts — DIN 603 / ISO 8677 / ISO 8678

Stainless steel is the corrosion-resistant choice, graded as A2 or A4 under ISO 3506 and chosen when the fastener is exposed to moisture or the outdoors. A2 (typically 304) suits general outdoor and indoor-wet use; A4 (typically 316) adds resistance to chlorides and marine environments. Strength follows ISO 3506 (for example A2-70, A4-80) and is set mainly by cold working, so the classes differ from carbon-steel property classes. Outdoor structures, food and marine equipment, and anywhere a bare corrosion-resistant finish is preferred over a coating. A2 and A4 are largely non-magnetic and cost more than carbon steel. The table below is controlled selection guidance, not a claim that every listed grade is supplied. Confirm the exact material, grade and mechanical requirements in the quotation.