M4 / 4mm Washers
Various pack quantities available
Other diameters of Heico Washers from M3 up to M20 Available on our shop
Very High Quality Washers
Heico-Lock® is the wedge locking system that uses tension instead of friction to give you ultimate security against the bolt loosening effects of vibration and dynamic loads
Why choose Heico-Lock® ?
High Quality product meeting the requirements of both DIN 65151 & DIN 25201-4.
Produced in Ense, Germany with over 100 years of experience successfully supplying fasteners to the likes of Audi, BMW, Renault, Jaguar, Land Rover, Volkswagen and Siemens.
How does Heico-Lock® work?
Conventional fasteners often rely on the physics of friction instead of tension to maintain clamp load e.g. nyloc nuts, metal lock nuts,
safety-wire, thread adhesives etc. but this offers limited performance.
With HEICO-LOCK® the unique tension based design of the washer system provides superior resistance to constant vibration,
high dynamic loads and thermal cycling.
The HEICO-LOCK® system consists of a pre-assembled pair of washers with inclined cams on the inside and radial teeth on the outside.
Tightening of the nut/bolt creates a ‘gripping’ action of the teeth thus seating the mating surfaces.
The angle of the cams (α) between the HEICO-LOCK® washers is greater than the thread pitch (β) of the bolt. This angle means the expansion in thickness of the HEICO-LOCK® washers is greater than the possible longitudinal movement of the bolt along the thread.
Bolt & Washers
With HEICO-LOCK® any bolt loosening results in the internal cams separating and their movement across each other results in an increase in tension and clamp load. During removal, only the cam surfaces move, resulting in low off torque force.
Differing Friction Coefficient between HEICO-LOCK® cams and radial ridges
The cams on the separation plane (joint face) of the individual washers of the pair show a much lower friction coefficient (µi) than the friction coefficient on the radial ridges on the outside of the pair of washers (µo).
Any loosening through a dynamic load will always lead to movement only across the face of the cams of the washers.
Any Questions please ask