How It Works
How It Works
Wedge Washer® is designed to prevent bolted joints from loosening under vibration and dynamic loading by using a mechanical locking principle.
Each washer set is supplied as a pre-assembled pair. The outer faces feature hardened serrations that grip into the bolt head, nut, and joint surface during tightening.
The inner faces feature angled cams with a cam angle steeper than the thread pitch. Once tightened, any loosening force must act through these cam faces, creating a wedge effect that increases clamp load rather than reducing it.
The joint can only be released by deliberate untightening, forcing the cams over one another. No re-tightening is required.
Features & Benefits
- Performs best in aggressive acidic environments
- Pitting resistance equivalent number (PREN) 68
- Highly resistant to crevice corrosion and stress corrosion cracking
- Resists vibration and dynamic loading (DIN 25201)
- Maintains preload and clamping force
- Eliminates need for re-tightening
- Surface hardened to ≥700HV0.1
- Temperature range -256°F to 932°F
- Easy to install, no special tools required
- Sizes M4 to M20, standard and large OD
Common Questions
Do I need one Wedge Washer or two?
It depends on the joint. If the connection is blind and the fastener can only loosen in one direction, a single Wedge Washer is required. For a through-bolted joint where loosening could occur from either side, two Wedge Washers are required, one under the bolt head and one under the nut.
When should I specify C276 instead of stainless steel?
C276 is a super alloy often used alongside stainless steel, and it performs best in aggressive acidic environments. It is highly resistant to pitting (PREN 68), crevice corrosion, and stress corrosion cracking. Specify it for applications in chemical processing, waste treatment, and oil and gas where stainless steel would not provide sufficient resistance.
What torque should I use with these washers?
There is no single torque value suitable for every application. Material strength, friction, clamping length, and embedment all influence the final result. When using stainless materials we always recommend using a lubricant to avoid thread galling. Tightening torque and clamp load guidelines for grades A2 and A4 fasteners are provided in the Wedge Washer® brochure. Each critical bolted joint should be analyzed individually by a design engineer.
Can Wedge Washers be reused?
Wedge Washers are supplied as a pre-glued pair for correct first installation. The adhesive ensures correct orientation and has no technical function once installed. If removed, the washers separate into two pieces and must be reinstalled correctly, with the cam faces together and the serrated faces facing outward.
How do I verify a Wedge Washer is functioning correctly?
Tighten the joint to the specified torque, then mark a vertical line across the bolt head or nut, both washer halves, and the mating surface. Untighten the joint. If functioning correctly, the line on the mating surface remains aligned with the contacting washer half, while the line on the bolt head or nut separates. This confirms serration engagement and cam function.
Where can I find full Wedge Washer specifications and torque data?
Complete dimension tables, tightening torque and clamp load guidelines for grades A2 and A4 fasteners, Junker Test performance data to DIN 25201, and installation guidance are all available in the Wedge Washer® catalog. Download the Wedge Washer® Catalog (PDF), or contact our engineering team for application-specific support.
Measurements & Specifications
Super Alloy Grade N10276
| Washer Code | Bolt Size (Metric) | Bolt Size (US) | Inner Diameter (in.) | Outer Diameter (in.) | Thickness (in.) | Approx. Weight (lb/100 pairs) | Select QTY | Add to Quote Form |
|---|---|---|---|---|---|---|---|---|
| WW-M4SS276 | M4 | #8 | 0.173 | 0.299 | 0.091 | 0.095 | ||
| WW-M5SS276 | M5 | #10 | 0.213 | 0.354 | 0.091 | 0.130 | ||
| WW-M6SS276 | M6 | 0.256 | 0.425 | 0.091 | 0.190 | |||
| WW-M8SS276 | M8 | 5/16" | 0.343 | 0.531 | 0.091 | 0.256 | ||
| WW-M8LDSS276 | M8 | 5/16" | 0.343 | 0.654 | 0.091 | 0.485 | ||
| WW-M10SS276 | M10 | 0.421 | 0.654 | 0.091 | 0.386 | |||
| WW-M10LDSS276 | M10 | 0.421 | 0.827 | 0.091 | 0.820 | |||
| WW-M12SS276 | M12 | 0.512 | 0.768 | 0.091 | 0.510 | |||
| WW-M12LDSS276 | M12 | 0.512 | 1.000 | 0.118 | 1.810 | |||
| WW-M16SS276 | M16 | 5/8" | 0.669 | 1.000 | 0.118 | 0.153 | ||
| WW-M20SS276 | M20 | 0.843 | 1.181 | 0.118 | 1.810 |
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