Kinmar® Permanent Nuts

Permanent Kinmar® security nuts represent the top level of protection against theft and vandalism. Unlike conventional nuts that can be easily removed with standard tools, these patented security nuts incorporate a one-way clutch mechanism that permits installation and re-tightening using matching driver sockets but prevents unauthorised removal. The innovative design eliminates the vulnerabilities associated with traditional shear nuts by providing operator-controlled torque settings and unlike a shear nut, does not leave rough edges or bare unplated metal that could compromise the finish or corrode.

What security rating are Kinmar® Permanent Nuts?

Kinmar® Permanent nuts have the highest security rating, "Maximum Security"; 5 of 5. The permanent Kinmar® requires specialised tooling, this tooling is patented and distribution of the tooling is tightly controled. Furthermore the shape of the pattern means this is a one way fixing, it can only be tightened. The tools will slip and cannot grip the fixing to be loosened.We also offer a similar nut with a rating of 4 of 5, however it is removable.
Please note that to preserve the integrity of our security products, the relevant tooling is not available online.It is available by request, and only to registered businesses.

Available Materials and Style Options

• A2 Stainless Steel (304/18-8 grade) - Natural finish with exceptional corrosion resistance
• Bright Zinc Plated (CR-3) - Case hardened steel with electroplated zinc finish
• Geomet 500B Coating - Advanced zinc-aluminium coating with superior environmental protection
• Permanent Kinmar® Nuts - One-way clutch mechanism prevents removal once installed
• Removable Kinmar® Nuts - Five-segment drive pattern allows maintenance access
• Thread sizes from M5 to M12 with custom sizes available to order

Key Features and Benefits

• Patented drive systems requiring matching restricted-availability tools for maximum security
• Salt spray resistance up to 1000 hours (Geomet finish) for coastal and marine environments
• Smooth, aesthetically pleasing finish with no sharp edges for public safety compliance
• Operator-controlled torque settings eliminate coating damage and rough surfaces

Related Vital Parts Products

• Shear Nuts - Permanent security nuts with breakaway heads for tamper-proof applications
• Pin Torx Barrel Nuts - Tamper-resistant barrel nuts for secure flush mounting applications

For comprehensive guidance on selecting the right security fastener for your application, explore our Complete Guide to Security Fasteners which covers security ratings, applications, and installation best practices for professional installers and facilities managers.

Call Vital Parts

For quick quotes, same-day dispatch, custom sizes, or bulk discounts, call our sales line on 01233 713 581. Businesses can register for a Vital Parts Business Account to benefit from priority shipping, trade pricing, free product samples, credit accounts, and a dedicated account manager specialising in security fastener solutions.