Tamper Proof Fasteners

Which tamper proof drive should I choose?

Start with a question most people skip: will anyone ever need to take this apart? That single answer eliminates half the catalog. If the fastener is going in permanently, a one-way screw or a break-away shear nut is the strongest deterrent available, because there is no correct tool that reverses them. If maintenance staff need periodic access, you want a reusable drive like pin-in Torx, spanner, or tri-groove, where an authorized person with the right bit can service the assembly in seconds. Getting this backwards is expensive in both directions: one-way screws on a panel that needs quarterly inspection means drilling them out every time, and a serviceable drive on something you never want opened is weaker protection than it could have been.

Security drive types we stock

• Spanner, also called snake eye, with two small holes in the head engaged by a forked bit. Common on bathroom partitions, gutters, and public fixtures
• Pin-in Torx, the familiar six lobe star with a pin in the center that blocks any standard Torx bit. Requires a bit drilled to clear the pin
• Pin-in hex, a socket drive with a central pin, so an ordinary Allen key cannot enter
• One-way, with ramped quadrants that let a standard driver tighten the screw but cam out when turned the other way. Permanent by design
• Tri-groove nuts, tapered and grooved so pliers and grippers slide off, driven by a matched socket
• Break-away shear nuts, tightened until the drive hex snaps off, leaving a smooth cone nothing can grip

What we stock

• Security machine screws in one-way round head, spanner flat, oval, and pan head, and pin-in Torx button and flat head, in 18-8 and 316 stainless
• Security self-tapping and self-drilling screws in spanner flat, oval, pan, and truss head, pin-in Torx button, flat, and pan head, and one-way, in 18-8 and 410 stainless
• Tamper proof nuts in break-away shear and tri-groove styles, in 304 and 316 stainless and Zamak 5 zinc alloy
• Tamper proof socket set screws in 18-8 stainless, from #8-32 through 3/8-16, including nylon patch versions
• Drivers and bits including Torx security L-keys from T6 through T55, star drive screwdrivers, power bits in multiple lengths, T-handles, spanner bits, pin-in hex bits, and tri-groove sockets
• Tamper proof kits for license plates, sign mounting, and general assortments

Common applications

• Public restrooms, bathroom partitions, and institutional fixtures
• Road signs, traffic hardware, and municipal infrastructure
• License plates, vehicle hardware, and fleet equipment
• Electrical enclosures, control panels, and utility cabinets
• Schools, correctional facilities, and transit stations
• Retail displays, vending equipment, and outdoor amenities

Every security fastener needs its matching driver, so check our tamper proof drivers and bits before ordering screws. For sign and plate mounting, our tamper proof kits pair the fasteners with the tool in one purchase.

Related Categories

• Security Machine Screws
• Security Self-Tapping Screws
• Tamper Proof Nuts
• Tamper Proof Drivers & Bits
• Tamper Proof Kits

Tamper Proof Fastener FAQs

Are tamper proof screws actually impossible to remove?

No, and it is worth being clear about that. Security fasteners raise the effort, time, and visibility of removal rather than making it impossible. Common bits like pin-in Torx and spanner are now sold in retail hardware stores, so those drives deter opportunistic tampering rather than a determined, prepared attempt. For higher security, one-way screws and break-away nuts are stronger because no correct removal tool exists.

How do you remove a one-way screw?

Not with the drive, since it is built to cam out in reverse. The usual methods are cutting a slot in the head with a rotary tool and backing it out with a flat blade, gripping the head with locking pliers if it protrudes enough, or drilling the head off entirely. All three damage the screw, which is the intent.

What is the difference between a spanner and a snake eye screw?

They are the same thing. Spanner is the technical name, snake eye is the shop term, and it comes from the two round holes in the head that look like a pair of eyes. Both are driven by a forked bit with two pins.

What are tri-groove nuts and how do they work?

Tri-groove nuts have a tapered, coned body with three shallow grooves around the outside. The taper means pliers, pipe wrenches, and vise grips slide off rather than biting, and the grooves are the only purchase point. A matched tri-groove socket engages those grooves to install or remove. They are also called T-groove, trident drive, and coned trident nuts.

How do break-away shear nuts work?

They have a hex section on top of a smooth cone. You tighten with an ordinary wrench until the hex twists off at a designed torque, leaving a rounded cone with nothing to grip. There is no removal tool, so they are for permanent installations such as street sign posts.

Which material should I choose?

18-8 and 304 stainless cover most general and outdoor use. Choose 316 for coastal, marine, or chloride exposure. 410 stainless appears on self-drilling security screws because it hardens enough to drill its own hole. Zamak 5 zinc alloy is the economical option on security nuts for non-critical applications.

Do I need a special driver for every drive type?

Yes, and that is the point. Each drive requires its own matching bit, and buying screws without the driver is the most common ordering mistake in this category. Check the drive style and size against the bit before you order.