Tightening

When the bolt and/or nut is tightened, the teeth grip and seat the mating surfaces. Since the cam angle α, is larger than the thread pitch β, a wedge effect is created by the cams, preventing the bolt from rotating loose.​ The Nord-Lock wedge-lock washer is locked in place, allowing movement only across the face of the cams. Any attempt from the bolt/nut to rotate loose is blocked by the wedge effect of the cams.

Untightening

When a bolt is untightened with a wrench, the pair of washers expand more than the corresponding pitch of the thread, allowing the bolt/nut to rise. Nord-Lock wedge-lock washers positively secure the fastener in a joint which is subjected to any kind of vibration or dynamic loads.

Features

• Standard range available for bolt sizes M3 - M130
• Washers available in 5 different materials - steel, stainless steel, 254 SMO®, INCONEL® / HASTELLOY® and C-276 INCONEL® 718
• Washers available with enlarged outer diameter (SP washers)
• Reliable bolt securing system at high and low clamp loads

How it works

1. Upon tightening the fastener, the X-series washer flatten and the serrations engage the contact surfaces
2. Since the cam angle α, is larger than the thread pitch β, the wedge-locking effect prevents any rotation of the fastener
3. Directly after tightening, the joint settles and the fastener sinks into the surface material
4. The washers immediately deflect and the spring effect (Fs) counteracts the slackening movement of the bolt, preventing loss of preload on the joint

These multiple functions continuously act on the bolted joint to maintain preload and prevent spontaneous bolt loosening - serving as a effective solution for vibration, dynamic loads, settlement and relaxation. 

Features

• Standard range available for bolt sizes M6 - M20
• Washers available in steel material
• Washers available with enlarged outer diameter (SP washers)
• Prevents bolt loosening caused by vibration and dynamic loads, and compensates for loss of preload due to settlement and relaxation