The triangle screw - formally called a triangular recess or TA drive - uses a simple equilateral triangle-shaped socket. It is a security fastener: the uncommon shape deters casual removal. You will find them on children's toys, battery compartments, some appliances, and commercial equipment.
Where Triangle Screws Appear
- Children's toys - battery compartments use triangle screws so young children cannot access batteries (a safety requirement)
- McDonald's restaurant equipment - playground structures, self-service kiosks, and restroom fixtures
- Some household appliances - certain models of vacuum cleaners, coffee makers, and alarm panels
- Electrical enclosures and meter boxes in some regions
- Elevator control panels and public utility equipment
Triangle Screw Sizes
Triangle (TA) bits are sized by the distance between the flat sides of the triangle, measured in thousandths of an inch:
| TA Size | Triangle Width | Common Application |
|---|---|---|
| TA14 | 1.4 mm (0.055") | Small toy battery compartments, alarm panels |
| TA18 | 1.8 mm (0.070") | Standard toy screws, small appliances - the most common size |
| TA23 | 2.3 mm (0.091") | Larger enclosures, commercial equipment, McDonald's fixtures |
| TA27 | 2.7 mm (0.106") | Utility meters, larger industrial panels |
Getting the Right Bit
Triangle bits are not common in standard bit sets. You will usually find them in dedicated security bit sets or purchase individual bits. A TA18 bit handles the majority of toy and appliance triangle screws. If you are a parent dealing with battery compartments, a single TA18 bit is the only tool you need.
In a pinch, some people use a small flat head screwdriver pressed into one side of the triangle. This works on loose screws but damages the recess and is not reliable. A proper TA bit costs less than a dollar - just get one.
