Torx

Torx (of English Torque -. Torque) is the designation for a screw - driver profile in multi- round shape. It resembles a Star of David with rounded ends and corners. The drive can also transmit high torques without damage to the screw head.

The term " Torx " is a registered trademark of the inventor, the U.S. Camcar in Rockford (Illinois ), which belonged to the system of the division of Textron Textron Fastening. The Torx patent expired in the early 1990s, however, protected the name remains. 2006, the division was sold to Platinum Equity capital and renamed Acument. The generic ( unprotected ) name for it is six- round.

General

The Torx profile ensures optimum power transmission. Because of the vertically extending drive surfaces no increased pressing force when tightening is required, and there are no preload forces (cam -out, see also axial force ). This cordless screwdriver can be used with high torque for fast fixing without damaging the inner profile. Another advantage of the recess shape is that rotational forces rather than localized attack (such as the Allen - system ) at the corners, but the middle and flat on the flanks of the individual prongs. This makes the system much less wear. Particularly suitable is the Torx system for assembly robots in automated manufacturing. Here are frequently used self-tapping or self-tapping screws are used, which cut the thread even when screwed into a hole or shape (metal ) or memorize (plastic). Pneumatically or electrically driven screwdriver should have an adjustable torque to prevent over-rotation and thus damaging the thread. A special case are called plank screws with cutting tip, thread and plain body whose small head is drawn when it is screwed into the surface of the wood plank. Other applications are in surgery ( fracture treatment) and dental prostheses (implants ).

There are torx and external TORX screws. The term T represents Torx inner profile and first came on the market. Then the outer profile shape E ( external) has been developed. The size designations of the T- tools were set arbitrarily, however, the key length is at E derived from Übereckmaß the flanks.

In the modification Torx TR ( Tamper Resistant, tamper-proof ) is located in the center of the profile a pin that prevents you can turn this screw with a normal Torx or flat-blade screwdriver. This profile is often used in devices to discourage unwanted access.

Female Torx screws are also referred to as I- Star or indoor Stern (English Star ). In describing the internal serration bolts poses the confusion with multi-tooth triple square. The key attack has been found as a six- round input into the international standardization, hexalobular is standardized in EN ISO 10664. The screw itself is standardized 14583 flat head screws with hexagon round to EN ISO. Both standards are also published as DIN standard.

In order to process these screws automatically or semi-automatically, they may be collated into a Nagelgurt. In the automotive sector screws are very often processed automatically with Torx drive today, but not in magazines, but come Schraubautomaten with the possibility of separation of loose supplied screws are used.

So-called nail screws are also partially made with Torx head. You are driven by a compressed air nailer and can be solved using a screwdriver or cordless screwdriver again.

The company Synthes Medical uses a variant of Torx under the name Star Drive for implants. Star Drive is partially compatible with Torx.

Key sizes (excerpt)

In the following table, the maximum diameter and the tightening torque are shown in Nm. It should be noted that the maximum torque is dependent on the material that the material condition and the coefficient of friction under the head and the thread.

The diameter data refer to the distance between two opposite points of the star.

Alternatives, further developments

Torx Plus

A further development of the Torx drive system is the patented in Germany by early 2012 Torx Plus system. Compared to standard Torx have the cam another ( " flatter " ) form, which are described by ellipses hanging together, making a real drive angle of 0 ° is given in some areas. This results in higher torques can still be transmitted. The drive Torx Plus screws with normal Torx keys is possible in an emergency ( high wear ), but not vice versa.

HexStix

For sizes T15 to T50, the Phillips Screw Company offers a compatible system under the name HexStix Stable Drive system. This An-/Abtriebe are labeled H15 to H50. The advantage of HexStix against Torx is a reduced slippage of the screw from the tool even without magnetic holder.