What Is a Torx Socket?
Torx sockets are tools used in combination with ratchet handles.
TORX® is a registered trademark of Acument Intellectual Properties, LLC.
T-type screws have a hexagonal star-shaped groove on the screw head, and a torx tool is inserted into the groove to tighten or loosen the screw. Note that “screw” in this case does not refer only to the screw shape, but also to smaller-size screw products.
Torx screws are characterized by the large contact area between the tool and the hexagonal star shape when tightening/loosening screws, which prevents slippage and facilitates the application of high torque. Common names for torx sockets include “hex-lobe sockets” and “hexarobular hole sockets.
Uses of Torx Sockets
Torx sockets are available in two types: T-type sockets with a hexagonal star-shaped bit at the end and E-type sockets with a hexagonal star-shaped hole at the end. Torx sockets are attached to a ratchet wrench or electric drill to tighten or loosen torx screws.
The hexagonal star-shaped groove or outline of the screw head allows for strong engagement between the torx Socket’s bit and the screw, resulting in efficient torque transmission. It is suitable for high-strength fastening areas.
Because of their excellent features and workability, they are used in a wide range of fields, such as in the automotive industry and various industrial machines. Torx screws are widely used in the U.S., Europe, and other foreign countries, and in recent years, torx screws have been frequently seen in Japan as well.
Characteristics of Torx Sockets
The hexagonal star shape of the torx screw provides the following features.
- Torque is applied to the center of the screw for efficient torque transmission
- Special tool does not easily pull out from the screw
- Durable and resistant to wear and cracking
- Good design quality
The general screw shapes such as cross and hexagonal are straight, so when torque is applied during screw tightening/loosening work, the screw makes contact with the tool at a point and the torque tends to be lost.
On the other hand, the hexagonal star shape of the torx screw is not straight but has a petal-like curved line, which makes it easier to contact the tool, resulting in superior torque transmission efficiency. The star shape also makes it easier for the tool to contact with the screw, which is highly efficient in transmitting torque. The contact also prevents slippage even when force is applied to tighten or loosen the screw since the torque is applied to the center of the screw instead of dispersing the force. As a result, the tool is less likely to slip out of the screw.
Furthermore, from the point that force is dispersed at the interview point, it is difficult to lick the screw threads because the force is not concentrated in any one part of the hexagonal star shape, thus increasing durability. In addition, the hexagonal star shape looks like a pattern, making it an excellent design feature.
How to Select Torx Sockets
1. Screw Size
The bit size of T-type torx sockets (the size of the hexagonal star tip) generally ranges from T4 (bolt thread diameter M2) to T100 (bolt thread diameter M22), with the higher number after the “T” indicating a larger thread size.
E-type torx sockets have hole sizes ranging from E4 (bolt thread diameter M3) to E24 (bolt thread diameter M18), and as with the T-type, the larger the number after the E, the larger the screw size.
Torx sockets must be the same size as the torx screw. It is important to carefully check the size of the torx socket to ensure that it is compatible, as using the wrong size torx socket may damage the torx screw.
2. Screw Shape
There are two general types of T-shaped torx screw shapes: TORX (T) and TORXplus (IP). Compared to ordinary TORX bits, TORX-Plus bits have rounded groove corners to prevent hole collapsing and cam-out (lifting of the bit when tightening) when tightening screws and to allow for more powerful torque tightening.
Note that torx plus socket bits cannot be used to tighten torx screws, but torx socket bits can be used to tighten torx plus screws. However, it is preferable to use a dedicated torx sockets bit whenever possible.
3. Length
There are several different bit lengths for T-type torx sockets and several different lengths for E-type torx sockets, and it is important to select the right one for the intended use.