Torsion Grips
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 tighten 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.
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.
10 Nm - 4 Independent Jaws
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.
Collet
A variety of different size collets are available.
Pneumatic Grips
Biaxial torsion tests can be performed with Pneumatic Grips especially if the torsional force is not very high. This setup is popular in the biomedical industry since most products are only intended for use with humans instead of machines.
Torque Testing Grips
The Torque Testing Grips hold a container in a clamping base while the upper grip turns the cap or closure, for application and removal torque testing of bottles and similar packaging.
Torsion Grip Options
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10 N·m four-jaw chuck: 3 in diameter body with independent, reversible jaws for irregular shapes.
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50 N·m self-centering keyed chuck: all four jaws tighten together for low runout; reversible jaws hold outside or inside diameters.
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Collets: a range of sizes for small round specimens, wire and pins.
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Pneumatic torsion grips: fast clamping for lower-torque biomedical tests.
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Torque testing grips: hold a container while the upper grip turns the cap, for closure application and removal torque.
Torsion grips mount on a round back plate with a threaded bolt pattern. Tell us your machine’s torque cell and bolt pattern and we will match it.
Torsion Testing Applications
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ASTM F543: torsional properties of metallic medical bone screws
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ASTM A938: torsion testing of wire
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Axial-torsion and biaxial testing of medical devices, shafts and fasteners
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Cap and closure torque for bottles and packaging
Torsion Grip FAQ
Why does runout matter?
If the specimen is off-center, it wobbles as it turns, which adds bending and spoils the torque reading. Self-centering chucks and collets keep runout low.
Can I combine tension and torsion?
Yes. On an axial-torsion machine the same grips carry axial load and torque, so check both ratings when choosing a grip.
Do torsion grips fit my machine?
We match the back plate to your torque cell and can supply adapters. See all of our tensile grips, or contact us for a quote.