Tamper Proof Fasteners
What Are Tamper Proof Fasteners?
Tamper Proof Fasteners (often called Tamper Resistant, Security Screws or Security Fasteners) are nuts, bolts and screws with an unconventional drive style designed to deter vandalism or tampering with the installation. In addition to the drive style, Tamper resistant fasteners are also engineered to be difficult, if not impossible to remove without the proper bit or a specifically designed tool. Different Manufacturers and engineers have taken this principle into developing new designs which are outlined below.
Tamper Proof Fasteners are used commonly in public areas where loss prevention and deterring tampering or vandalism are key. They are commonly seen in Hotels, Restaurants, Electronics, Automobiles, and perhaps most commonly in Public Restroom Partitions and Stalls. Stainless Steel is almost always used for tamper proof fasteners because of the set it and forget it mentality. Stainless steel is corrosion and rust resistant which is why it is commonly used in long lasting applications, exterior environments, and applications exposed to moisture.
Spanner (Snake Eye) Security Screws
Tamper Proof Spanner or "Snake Eye" security screws are installed using a spanner bit. Spanner Screws are commonly referred to as "Snake Eye" because of the two-dot drive system. Spanner security screws are used for securing materials from being tampered with, such as gutters, license plates, grills in jails, schools, boats and cars. They are also used in food prep and processing areas. You will often see security screws used in bathroom stalls and other public locations. Spanner screws can only be installed or removed with a spanner bit, which fits a pin into each of the screw's two drive holes. Since Spanner screws can only be installed or removed through spanner bits, they are very resistant to tampering.
Torx (6 Lobe with Pin) Security Screws
Torx® with pin security drive can only be driven with security bits and are used to prevent tampering and theft. Security Screws in this variety are characterized by the 6 lobe, or star drive with a central pin. The pin grants additional tamper resistance as it prevents conventional screwdrivers and grabbing devices from tampering with the original installation.
One Way Security Screws
One Way Security Screws are also known as One Way Slotted, Irreversible, and One Direction Screws. The head of the screw features a slotted drive that is designed to instantly cause cam out if the driver is turned in the wrong direction. This is achieved by manufacturing the drive-in quadrants that are gradually raised to accept the driver bit when turning the screw right, and reject it when turning the screw left. The One-Way drive makes installation of the screws easy, requiring only a standard slotted bit, but removal of the screw difficult (if not impossible) without drilling or a specifically designed removal tool.
Hex Socket With Pin Security Screws
Hex Socket with Pin Tamper Proof Fasteners feature a Hex or Socket head drive with a central pin that prevents installation or disassembly with a standard hex bit or Allen wrench. To remove these easily, a special version of a hex wrench will be needed.
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 are tamper resistant.
Break Away Shear Nuts
Shear nuts, or break away nuts, are coarse threaded nuts designed for permanent installation. They are commonly seen on street signs and other areas where tampering or security are considered a concern. These nuts are built with a cone, hex nut and a designed weak point between the two. Once the cone portion is tightened against the installation material, the torque begins to build. After enough torque is applied, the hex nut portion will break away or shear off the cone portion, leaving only cone portion left against the installation material.
Tamper Proof Bits
With the exception of the One-Way drive style, all Tamper Proof Fasteners are installed or removed with a corresponding bit or tool to match the fastener's drive style. These include sockets, insert bits, power bits and screwdrivers. The important aspect of that makes a fastener "tamper proof" is this drive style, because it does not match standard tools.
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