About Tamper Proof Screws
Most applications of tamper proof screws are intended to be difficult to remove. Some tamper proof screws are designed for anti-theft purposes (eg. Tamper proof wheel locks). Some are designed to prevent from disassembling a working device (eg. cellphones). Lastly, some tamper proof screws are applied as permanent fixings, which can never be unscrewed (eg. security gates). Here are some typical tamper proof screw types:
Hex Socket Pin-in Screws
Standard hex socket screws can be fixed or unscrewed with a hex bit or an Allen wrench. In contrast, hex socket pin-in screws require a customized tool to tighten or remove them.
Torx Pin-in Screws
Same as the above, standard Torx screws can be fixed or unscrewed with a Torx bit or a Torx wrench. In contrast, Torx pin-in screws require a customized tool to tighten or remove them.
Snake-Eye Screws
Also named Pig-Nose screws, which have 2 holes drilled on screw head, which require a customized tool to drive or remove. Snake-Eye screws are applied when a product requires cosmetic appearance.
One-Way Screws
This type of screw can only be tightened one way with a slotted screw driver (clockwise) and cannot be unscrewed (counterclockwise). One way screws are usually applied on permanent fixings where screw removal is not really necessary.