The following guide will help you understand Torx bits, what sizes are out there, and why these bits are gaining traction (literally and figuratively). Security Torx has its own set of variations, and many other variations of Torx drives are available in Security or TR versions. There are also a lot of emergency DIY methods out there, such as softening a piece of plastic and shaping it to fit. A version known as Security Torx, Tamper-Resistant Torx (often shortened to Torx TR) or pin-in Torx contains a post in the center of the head that prevents a standard Torx driver (or a straight screwdriver) from being inserted. United Kingdom (Deutsch, English) (Nederlands, français, English) (Português) (Български) (English, français) (简体中文, English) (čeština, English) (dansk, English) (eesti keel) (suomi, English) (français, English) (Deutsch, English) (magyar, English) (English) (English) (Italiano,English) (한국어) (latviešu) (lietuvių k.

Rather than rely on the tool to slip out of the screw head when a desired torque level is reached (which risks damage to the driver tip, screw head, or workpiece), torque-limiting driver designs achieve a desired torque consistently. The official generic name, standardized by the International Organization for Standardization as ISO 10664, is hexalobular internal. A tamper-resistant version of Torx Plus exists having five lobes rather than six, plus a solid post in the center, and is used for security as the drivers are uncommon. A smaller number corresponds to a smaller point-to-point dimension of the screw head (diameter of circle circumscribed on the cross-section of the tip of the screw driver). Many consumers feel that star bits are better than Torx because the latter uses a restricted manufacturing license to use the patterns.

A security Torx L-key and fastener with holes for a safety pin to hinder disassembly with an ordinary Torx key. The green circle, passing through the six points of contact between the two components, represents the direction of the rotational force being exerted at each of those points.

The magnitude of this force is proportional to the cotangent of the angle (depicted in orange) between the green circle and the contact plane. It features a second recess to create a "stick-fit" engagement (branded Frixion Fit), designed to minimize wobbling (branded Stable Drive) without pressing and the need for magnetic bits, a feature that can be important to certain industrial users. For the Torx type of design, the angle is much closer to 90° than in the case of the hex head, and so for a given torque the potentially damaging radial force is much lower.

There’s a lot of potential confusion when it comes to whether or not you should include Torx bits (aka: star bits) in your toolkit.

The "external" variants of Torx head sizes (see below) are described using the capital letter "E" followed by a number ranging from E4 to E44. Because the plane of contact is not perpendicular to this circle, a radial force is also generated which tends to "burst" the female component and "crush" the male one. The development of better torque-limiting automatic screwdrivers for use in factories allowed this change. While it’s common to use the terms Torx and star interchangeably, there’s actually a bit of a difference between the two.

Yet star bits are so closely matched to the shape of Torx that they can easily be used as a substitute.