A washer looks simple, but choosing the wrong one can lead to loosening, corrosion or damaged surfaces. Here are the key factors our engineers consider.
1. Function
Flat washers distribute load; spring and wave washers maintain preload; toothed and knurled lock washers resist rotation; shims adjust clearance; eccentric washers allow alignment.
2. Material & hardness
Carbon steel suits most applications, spring steel is needed for preload, and stainless steel or copper for corrosion or electrical requirements. Match hardness to the bolt property class.
3. Surface finish
Zinc flake and zinc-nickel coatings offer high salt-spray resistance for underbody parts; plain or phosphate finishes suit interior use.
4. Standard or custom
DIN, ISO, ANSI and GB washers cover most needs, but special shapes often reduce assembly cost. Send us your drawing and we will recommend the best solution.