GB97 A4 316 Stainless Steel Flat Washer Plain Gasket Ring M1.6–M24

A4-70 grade 316 stainless steel flat washers to GB97 / DIN125 standard. Marine-grade 316 stainless steel with molybdenum addition provides superior corrosion resistance compared to 304 stainless — essential for saltwater, coastal, chemical, and highly corrosive environments where 304 SS would corrode. The standard choice for marine hardware, outdoor structures, and chemical processing equipment.

Key Specifications

Material	316 Stainless Steel
Grade	A4-70 (marine grade)
Standard	GB97 / DIN125 / ISO 7089
Type	Flat washer / plain gasket
Size Range	M1.6 – M24 (per variant)
Key Advantage	Molybdenum addition for chloride corrosion resistance

Why Choose 316 SS Over 304 SS Flat Washers?

Marine-grade 316 SS — molybdenum addition resists chloride pitting corrosion; essential for saltwater and coastal environments
Superior chemical resistance — resists acids, alkalis, and chloride solutions that would corrode 304 SS
A4-70 grade — higher corrosion resistance than A2-70 (304 SS); the correct choice for marine and chemical applications
DIN125 / GB97 standard — same dimensions as 304 SS washers; direct drop-in replacement
M1.6–M24 range — covers all standard metric sizes

Typical Applications

Marine hardware and boat fittings (saltwater environment)
Coastal and offshore structure fastening
Swimming pool and water treatment equipment
Chemical processing and food production equipment
Outdoor architectural and structural fastening
Medical device and laboratory equipment assembly

FAQ

Q: When should I use 316 SS instead of 304 SS washers?
A: Use 316 SS when the application involves: saltwater or marine environments, chloride-containing chemicals, food processing (chlorine cleaning agents), swimming pools, or any environment where 304 SS has shown corrosion. For standard indoor and general outdoor use, 304 SS is sufficient.

Q: Are 316 SS and 304 SS washers the same dimensions?
A: Yes. Both follow DIN125 / GB97 dimensions and are fully interchangeable. The only difference is the material composition and corrosion resistance.