Triple Square, also known as a 'XZN' are commonly found on German vehicles such as BMW, Mercedes, and Volkswagen. These screws are used in high torque applications such as cylinder head bolts and drive train components. Increasingly, triple square screws are found on other European and Asian makes of cars.

Other names used for Triple Square screws and drivers are "Double Hex", "Double Allen", and "Aircraft Screws". Despite this, "Double Hex" and "Double Allen" are misnomers.

The recess in these bolts is actually (as the name suggests) made of three squares, not two hexagons. The corners are 90°, not 120°. As they are not double hexes, an Allen key will not fit them properly.

The set comes complete with all commonly used sizes from M10 - M18 with the addition of M16H which is tamper-proof.

Ideal for a full time mechanic in a busy work shop, these bits are for professional use.

Made by professionals for professionals.