Compared to the classic hexagon profile (inside hexagon and outside hexagon), TORX® screws and tools are subjected to less radial forces and are therefore less damaged. The torque is transmitted more directly via the radial parts of the tooth flanks instead of via the almost tangential surfaces of the hexagon.

Due to the rounding of the inner tips, the notch effect on the circumference of the screw head or tool is very low with TORX®.

There are inside TORX® and outside TORX® screws. The designation T stands for TORX® internal profile and was first launched on the market. The outside profile Form E (= External) was then developed, which is why the designations of the individual profiles are usually abbreviated to T or TX and TE. The size designations of the inside TORX® tools were determined arbitrarily; in contrast, the size of the outside TORX® tools is derived from the overlap dimension of the flanks.

Inside TORX® screws are also known as I-star / internal star. In German standards, the TORX® wrench handle is called hexalobular in reference to the common outside and inside hexagon screws.

TORX® (from the word torque) is a trademark of Acument Intellectual Properties LLC. HAZET is licensee for the manufacture of TORX® tools.

The standard designation is (inside or outside) hexalobular socket.

[Wikipedia / Further explanation: en.wikipedia.org/wiki/Torx]