50 Nm - Self Centering, Keyed
This is the most standard torsion grip for higher force tests. By using a key, the self centering grip can be uniformly tightened across all 4 grip faces. The grip inserts are reversible in order to handle OD on small cylinders or ID for larger, hollow cylinders.
The diameter of this grip is 3 inches. Each Jaw is tightened independently which allows some flexibility in testing but is not always desirable due to runout. The jaws are reversible.
Torsion Grips are used to hold any sample that will be twisted. These grips are also commonly used in conjunction with Bi-Axial Tensile Machines where twisting and pulling is necessary. Similar to CNC lathe chucks, these bi-axial torsion grips use a self-centering mechanism to tight around the sample. This mechanism can use a key crank, or be keyless with a twisting body, similar to an electric hand drill. The torsion grip mounts flush to a circular back plate with a threaded drill hole pattern. Key areas of concern for application success involve runout, and the tensile/compressive forces.
A variety of different size collets are available.
Biaxial torsion tests can be performed with Pneumatic Grips especially if the torsional force is not terriby strong.. This setup is popular in the biomedical industry since most products are only intended for use with humans instead of machines.