Side-by-Side Comparison
Washers & Retaining Rings
Fender Washers vs. Lock Washers
Comparing 2 standards across 17 specifications. 17 key differences identified.
Comparing:
Fender Washers
Lock Washers
Fender washers feature an oversized outer diameter approximately three times larger than their central hole (e.g. 1/4" ID × 1.0" to 1.25" OD), designed to bridge enlarged holes and distribute clamping force across thin sheet metal, automotive panels, and wood.
Lock washers resist bolt loosening under vibration through spring preload and mechanical biting, standardized under DIN 127 (helical split spring washers), DIN 6798 (internal/external serrated tooth star washers), and DIN 2093 (Belleville conical spring discs).
Specification Comparison Table
17 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
ASME B18.22.1 (Large Diameter Flat Washers) / SAE J485 | DIN 127 Form B / DIN 6798 / DIN 2093 / ASME B18.21.1 |
|
Defining Characteristic
|
Outer diameter is ~3× to 4× the inner bolt diameter | — |
|
3/16" × 1.0" Fender Washer
|
ID: 0.219 in (5.6 mm) | OD: 1.00 in (25.4 mm) | Thickness: 0.050 in (1.27 mm) | — |
|
1/4" × 1.0" Fender Washer
|
ID: 0.281 in (7.1 mm) | OD: 1.00 in (25.4 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
1/4" × 1.25" Fender Washer
|
ID: 0.281 in (7.1 mm) | OD: 1.25 in (31.8 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
1/4" × 1.50" Fender Washer
|
ID: 0.281 in (7.1 mm) | OD: 1.50 in (38.1 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
5/16" × 1.25" Fender Washer
|
ID: 0.344 in (8.7 mm) | OD: 1.25 in (31.8 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
5/16" × 1.50" Fender Washer
|
ID: 0.344 in (8.7 mm) | OD: 1.50 in (38.1 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
3/8" × 1.50" Fender Washer
|
ID: 0.406 in (10.3 mm) | OD: 1.50 in (38.1 mm) | Thickness: 0.062 in (1.57 mm) | — |
|
1/2" × 2.00" Fender Washer
|
ID: 0.531 in (13.5 mm) | OD: 2.00 in (50.8 mm) | Thickness: 0.078 in (1.98 mm) | — |
|
Helical Split Washer Mechanism
|
— | Spring tension + sharp trapezoidal edges that bite into mating surfaces under counter-rotation |
|
M6 DIN 127 Split Lock Washer
|
— | ID: 6.1 mm | OD: 11.8 mm | Thickness (s): 1.6 mm | Uncompressed Free Height: ~3.2 mm |
|
M8 DIN 127 Split Lock Washer
|
— | ID: 8.1 mm | OD: 14.8 mm | Thickness (s): 2.0 mm | Uncompressed Free Height: ~4.0 mm |
|
M10 DIN 127 Split Lock Washer
|
— | ID: 10.2 mm | OD: 18.1 mm | Thickness (s): 2.2 mm | Uncompressed Free Height: ~4.4 mm |
|
M12 DIN 127 Split Lock Washer
|
— | ID: 12.2 mm | OD: 21.1 mm | Thickness (s): 2.5 mm | Uncompressed Free Height: ~5.0 mm |
|
Belleville Disc Spring (DIN 2093)
|
— | Conical shape maintains thousands of pounds of preload over high thermal expansion cycles |
|
Serrated Tooth Star Washer (DIN 6798)
|
— | Multiple teeth bite through paint/anodizing to ensure electrical bonding and ground continuity |