Side-by-Side Comparison
Washers & Retaining Rings
Flat Washers vs. Sealing & Crush Washers
Comparing 2 standards across 19 specifications. 19 key differences identified.
Comparing:
Flat Washers
Sealing & Crush Washers
Standard flat washers distribute fastener clamp load and prevent surface embedding, standardized under DIN 125 (ISO 7089 Form A metric without chamfer) and ASME B18.22.1 (Type A Narrow, Regular, and Wide series in imperial sizes).
Sealing crush washers create leak-tight fluid seals under compression on hydraulic fittings and automotive drain plugs, standardized under DIN 7603 (Form A solid copper/aluminum, Form C copper-asbestos/elastomer, and bonded Dowty seals).
Specification Comparison Table
19 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
DIN 125 Form A (ISO 7089) / ASME B18.22.1 Type A | DIN 7603 Form A (Solid) / ISO 1179 / SAE J514 |
|
M3 Flat Washer
|
ID: 3.2 mm | OD: 7.0 mm | Thickness: 0.5 mm | — |
|
M4 Flat Washer
|
ID: 4.3 mm | OD: 9.0 mm | Thickness: 0.8 mm | — |
|
M5 Flat Washer
|
ID: 5.3 mm | OD: 10.0 mm | Thickness: 1.0 mm | — |
|
M6 Flat Washer
|
ID: 6.4 mm | OD: 12.0 mm | Thickness: 1.6 mm | — |
|
M8 Flat Washer
|
ID: 8.4 mm | OD: 16.0 mm | Thickness: 1.6 mm | — |
|
M10 Flat Washer
|
ID: 10.5 mm | OD: 20.0 mm | Thickness: 2.0 mm | — |
|
M12 Flat Washer
|
ID: 13.0 mm | OD: 24.0 mm | Thickness: 2.5 mm | — |
|
1/4" ASME Type A
|
ID: 0.281 in (7.1 mm) | OD: 0.625 in (15.9 mm) | Thickness: 0.065 in (1.65 mm) | — |
|
3/8" ASME Type A
|
ID: 0.406 in (10.3 mm) | OD: 0.812 in (20.6 mm) | Thickness: 0.065 in (1.65 mm) | — |
|
1/2" ASME Type A
|
ID: 0.531 in (13.5 mm) | OD: 1.062 in (27.0 mm) | Thickness: 0.095 in (2.41 mm) | — |
|
M10 Sealing Washer (DIN 7603)
|
— | ID: 10.0 mm | OD: 14.0 mm | Thickness: 1.0 mm (Copper / Aluminum) |
|
M12 Sealing Washer (Oil Drain Plug)
|
— | ID: 12.0 mm | OD: 16.0 mm to 18.0 mm | Thickness: 1.5 mm |
|
M14 Sealing Washer (Standard Oil Drain)
|
— | ID: 14.0 mm | OD: 18.0 mm to 20.0 mm | Thickness: 1.5 mm |
|
M16 Sealing Washer (Gearbox/Diff)
|
— | ID: 16.0 mm | OD: 22.0 mm | Thickness: 1.5 mm |
|
M18 Sealing Washer
|
— | ID: 18.0 mm | OD: 24.0 mm | Thickness: 1.5 mm |
|
M22 Sealing Washer
|
— | ID: 22.0 mm | OD: 27.0 mm | Thickness: 1.5 mm |
|
Bonded Dowty Seal (Metal + NBR/FKM)
|
— | Steel outer ring with vulcanized inner trapezoidal elastomeric lip (Self-centering) |
|
Plastic Yield Mechanism
|
— | Ductile copper/aluminum crushes plastically into machining micro-grooves upon torquing |