Belleville Washers vs. Fender Washers
Comparing 2 standards across 16 specifications. 16 key differences identified.
The Belleville Washer (Conical Disc Spring / Cupped Spring Washer, standardized under DIN 2093 and DIN 6796) is a conical annular spring disc engineered to deliver massive axial spring clamping force across sub-millimeter deflection distances, maintaining bolted joint tension under extreme thermal expansion and dynamic vibration.
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.
Specification Comparison Table
16 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Specifications
|
DIN 2093 (Precision disc springs) / DIN 6796 (Heavy-duty bolted joints) / ISO 19643 | — |
|
Conical Geometry
|
Frusto-conical cup shape (cone height ≈ 0.5× to 0.7× disc thickness) | — |
|
Load Capacity
|
Extreme axial spring force (thousands of newtons in sub-millimeter stroke) | — |
|
Stacking Capabilities
|
Parallel Stacking (nests together to multiply load) or Series Stacking (tips touch to multiply deflection) | — |
|
Standard Materials
|
51CrV4 chrome-vanadium spring steel / 17-7 PH stainless / Inconel 718 (high temp) | — |
|
Primary Applications
|
High-voltage electrical busbars, engine cylinder heads, cryogenic piping, wind turbine bolts | — |
|
Governing Standards
|
— | ASME B18.22.1 (Large Diameter Flat Washers) / SAE J485 |
|
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) |