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316 Stainless Steel Metric Zamak 5 Zinc Alloy
Tri Groove Nut Drivers Zamak 5 Zinc Alloy
Tri-Groove Handles

Tamper Proof Nuts

Tri Groove Security Nuts

Tri Groove security nuts feature a tapered diameter, making the nuts resistant to gripping devices. Security nuts are installed using a special Tri Groove socket, which grips the indentations along the outside of the fastener to turn the nut along a thread. Tri Groove nuts are also referred to as T Groove, Trident Drive and Coned Trident Drive Nuts.

Tri Groove Nuts are commonly used with driver-less fasteners, such as carriage bolts for a secure assembly. If the nut is not easily accessible, the fastener assembly will be harder to be tampered with. Security Nuts are commonly used in public outdoor applications including campsites, parks, playgrounds, benches, cars and roof top tents. Stainless Steel Security Nuts are perfect for this type of application since they are rust and corrosion resistant.

Tri Groove Security Nuts are available in Zamak 5 Zinc Alloy and corrosion resistant 316 Stainless Steel.

UNC Coarse thread sizes available in diameters up to 5/8 inch.





316 Stainless Steel

Tri Groove Security Nuts in corrosion resistant 316 Stainless Steel (16%-18% Chrome, 10%-14% Nickel, .08% Maximum Carbon, 2.00% Maximum Molybdenum) This grade of stainless steel is used and recommended for applications in severe, harsh or marine environments. Its corrosion resistance is greater than 18-8 stainless, which is why we recommend using 316 stainless steel fasteners for salt water application. It is important to remember that even the salt in the air near a body of salt water can do damage to dry applications, so 316 is the material of choice. Common applications of 316 stainless steel fasteners include use on boats, docks, piers, and pools.

Zamak 5 Zinc Alloy

Zamak is an alloy of Zinc and Aluminium, sometimes also incorporating Magnesium and Copper. The added copper in Zamak 5 increases the strength, hardness, and corrosion resistance of the alloy, but reduces its ductility and dimensional accuracy compared to other Zamak Alloys.