A washer does only three jobs: spreading the load (protecting the clamped surface), locking (resisting loosening under vibration), and taking up clearance (absorbing tolerances or providing axial preload). Decide which job you need first, then pick the type.
| Type | Main function | Common standards | When to use |
|---|---|---|---|
| Flat washer | Spreads load, protects the surface | DIN 125 / ISO 7089; large OD: DIN 9021 / ISO 7093 | The most general-purpose; use the large-OD type when the clamped part is soft or the hole is oversized |
| Spring lock washer | Locking (axial spring force) | DIN 127 | The most common locking method for general vibration |
| Tooth lock washer (internal / external teeth) | Locking (teeth bite into the contact surface) | DIN 6797 / DIN 6798 (toothed / serrated) | Heavy vibration; external teeth lock more strongly, internal teeth look neater |
| Wave washer | Takes up clearance, axial preload | As marked on the item | Bearing preload, eliminating axial play and noise |
| Disc washer (conical / dished) | Elastic compensation under heavy load | As marked on the item | Limited space but higher spring force needed |
| Double washer | Flat + spring washer in one | As marked on the item | Saves an assembly step |
| Safety washer | Locking | As marked on the item | Stronger locking needed without using threadlocker |
The table only lists widely recognized standard numbers; wave, disc, double and safety washers come in many market forms — the actual standard and dimensions are always as shown on the product page. If you need a specific standard, state it in your inquiry.
Two notations are used side by side: by thread size (e.g. M10, meaning for an M10 screw) or by actual dimensions (ID × OD × thickness, e.g. 10.5*18*0.9). The same M10 has a different OD and thickness in different types; when the hole position or counterbore space is tight, check the actual dimensions on the product page.
Spring lock washers also come in three thicknesses — No. 1, No. 2 and No. 3 — for the same thread size; see the spring lock washer size chart.
Common options are zinc plated (electroplated), carbon steel, 304/316 stainless steel, nickel plated and aluminum. Choose stainless for outdoor or humid environments; zinc plated is fine for general indoor use. For hardness and corrosion resistance see the material comparison.
Click a size to open its product page (price and stock status); lists update automatically with our stock.