KEENSERTS are high strength threaded inserts made from stainless steel 1.4305 or AISI303.They are passivated according to EN 2516 or AMS 2700. Our KEENSERTS standard product range contains metric and imperial thread dimensions. Specials are available upon request.


KEENSERTS can be used in alloys, light materials, steel and cast iron to give increased thread strength in these low strength materials. They are also be used for thread repair enabling the damaged thread to be replaced with the same size thread.

KEENSERTS Solid configuration gives a high cycle life with multiple tightening and loosening of the bolt. Locking inserts have a dry film lubrication on the surface to protect the screw from galling.

KEENSERTS have a positive mechanical lock against rotation and vibration when kees are installed. Kees are made from stainless steel AISI302.

KEENSERTS have 2 or 4 pre-assembled kees depending on the size of the external thread. After installation of the kees into the parent material the assembly is positively locked in place.

Pull-out-strength for KEENSERTS . Calculation is as follows:

Pull-out-strength(N) = shear engagement (mm2) x ultimate shear strength of parent material (N/mm2) Shear engagement areas are shown on the KEENSERTS data sheets, only valid for full installed KEENSERTS.




Installation depth KEENSERTS of the is determined by the pre-assembled kees.

The installed depth of the KEENSERTS is based on the depth of the countersink.



Installation in hard materials

For very hard materials with a hardness greater than 30 HRC or 300 Vickers it is necessary to pre-broach the slots for the kees. The first step is to mark the position of the kees on the parent material. To do this wind the KEENSERTS in until the kees touch the surface of the parent material.

Mark the positions of the kees and unwind the KEENSERTS.

Then line up the blades of the broaching tool with the marked positions and push it in with a hammer or under a press, remove the tool and install the KEENSERTS. In some cases it may be necessary to run the tap back down the hole to clear out any burrs. Available for external metrical thread M5 and up and external imperial thread 1/4“ and up.


Typical Applications: