Metric 316 Stainless Steel Flat Washers (A4)
What are metric 316 stainless flat washers? Metric 316 stainless flat washers, grade A4, are general-purpose metric round washers that spread a fastener's load and protect the surface. Made from marine-grade 316 stainless, comparable to metric A4, they resist salt and chloride corrosion in coastal and marine metric assemblies.
When should I use A4 metric washers?
A4 is the metric designation for a molybdenum-alloyed marine-grade stainless comparable to 316, giving far better resistance to salt and chloride pitting than A2. As a metric flat washer it spreads clamping load while keeping that corrosion resistance in coastal, marine, and wash-down metric assemblies. Match the washer to your metric bolt size, such as M6, M8, or M10, and pair it with A4 metric bolts and nuts so the whole joint shares the same protection.
Why choose metric 316 stainless flat washers
- Marine-grade corrosion resistance: A4 is molybdenum-alloyed like 316.
- Metric sizing: matched to M-series bolt diameters.
- General purpose: the everyday marine metric washer.
- Match grade: pairs with A4 metric hardware.
Common applications for metric 316 flat washers
- Marine and coastal metric hardware
- Boats, docks, and saltwater exposure
- Wash-down and food-grade metric equipment
- Chlorinated and chemical environments
For general metric freshwater use, see A2 metric stainless flat washers, and browse every material on the main flat washers category.
Metric 316 Stainless Flat Washers FAQ
Is A4 the same as 316 stainless?
A4 is the metric grade comparable to 316. Both are molybdenum-alloyed marine-grade stainless with excellent salt and chloride resistance.
What metric sizes are available?
Common metric diameters such as M6, M8, and M10. Match the washer to your metric bolt size.
When should I choose A4 over A2?
Choose A4 for coastal, saltwater, and chloride exposure. A2, comparable to 304, suits general outdoor and freshwater use.