The twister is designed to check the number of twists required to fracture a wire. Normally furnished as a bench unit, these machines are also available as floor models, and as multiple twisting units for simultaneously testing two, three or more samples.

The standard, variable speed, motor drive makes up to 62 twists per minute (rpm) with a maximum torsion rating of 1,500in.lbs. A counter indicates the total number of twists, and automatically stops the machine when the specimen fails.

Wire samples up to 18in long can be accomodated. An initial tensile load of up to 150lb can be applied to prevent kinking. Load is read in 2lb, increment on a scale.

The 10,000in.lbf (1000 N.m) torsion tester is bench mountable and the moveable section slides on a guide rail. All other models are floorbased and are furnished with heavy duty slotted steel bed rails that are normally embedded in, or secured to, a concrete foundation to assure maximum rigidity and accessibility.

The moveable section on these higher capacity machines is mounted on four rollers that glide along these slotted rails and allow rapid positioning. Additionally, these rollers allow the moveable unit to compensate for any changes in specimen length during loading. The standard maximum distance between chucks is 7ft ( approx 2.1m); however, other lengths can be provided.