Rope Grips for Universal Testing Machines
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Products > Tensile Grips > Rope
Narrow or Cylindrical Cord
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Rope Grips are designed for tensile testing of cordage - ropes, strands, twine, thread, and wire. The smaller rope grips can be used for testing monofilaments used for sutures in biomedical applications. The sample string is wound around the drum several times before being secured with a type of vise fixture. Along with our standard mechanical product line covering 0 - 100kN, UGC also offers pneumatic versions of these grips which are opened and closed using air pressure.
The working principle for these grips involves the coefficient of friction of the underlying material. By winding the rope around itself several times, the frictional area is increased. This technique spreads the testing stress over a larger section of the rope which reduces the chance of failed tests due to bad sample breaks or slippage. The drum is sized appropriately based on the anticipated force of the test (kN or lbs).
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If you need a quick reference to all ASTM's that deal with Ropes and Cord refer to our blog post on Rope Grips.
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Scroll down to view all of our Rope Grips Products.
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Rope Grips, also called capstan grips, are specifically engineered for the tensile testing of cordage materials including ropes, strands, twine, thread, and wire. Their design is particularly effective for flexible specimens that are difficult to secure using traditional flat or serrated jaws. Smaller rope grips are commonly used for delicate applications such as monofilament testing for biomedical sutures, where preventing specimen damage is critical to achieving valid results. During setup, the sample is wound multiple times around a precision-machined drum before being secured with a vise-style clamping mechanism, allowing the load to be introduced gradually and evenly. Alongside our standard mechanical product line covering capacities from 0–100 kN, Universal Grip Company also offers pneumatic versions that open and close using air pressure. This improves operator efficiency, clamping consistency, and repeatability in higher-throughput laboratory environments.
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The working principle behind rope grips relies on the coefficient of friction between the specimen and the drum surface. Each wrap increases the frictional holding force, enabling the grip to restrain the specimen without excessive compressive stress that could otherwise crush fibers or alter test outcomes. By distributing the applied force across a larger contact area, this method greatly reduces the likelihood of premature failures caused by jaw breaks or slippage, ensuring the specimen fractures within the gauge length for more accurate tensile data. Drum diameters are carefully selected based on the anticipated test force (kN or lbf) and the material characteristics of the specimen, helping maintain proper bend radius and minimizing structural distortion during loading.
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If you need a quick reference to all ASTM's that deal with Ropes and Cord refer to our blog post on Rope Grips.
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Scroll down to view the full lineup of our Rope Grip products.
225 lb. Small Rope Grip - 1 kN
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The 1 kN Rope Grip is engineered with a more robust frame and higher clamping stability while maintaining the same fundamental capstan-style design as the smaller rope grip. This configuration allows the specimen to be wrapped around a smooth-radius drum before securing it in the jaws, distributing the applied force gradually and minimizing stress concentrations that could otherwise cause premature failure at the grip interface. As a result, the fixture is particularly effective for tensile evaluations of ropes, fine wire, braided cords, and high-performance synthetic fibers where preserving specimen integrity is critical to obtaining accurate strength data. Commonly paired with low-force universal testing machines, the 1 kN Rope Grip supports repeatable testing for quality control, product development, and material comparison, making it a reliable solution for laboratories and manufacturers working with flexible tensile members.
1K lb. Rope Grip - 5kN
The 1 kN Rope Grip is a heavier-duty version of the small rope grip but follows the same capstan-style design. Built with a stronger frame for improved stability, it helps maintain alignment during testing while delivering consistent, repeatable results. The specimen is wrapped around the drum before being secured, allowing the load to build gradually and reducing the chance of slippage or premature breaks at the grip.
These rope fixtures are commonly used for rope strength testing, wire tensile testing, and synthetic fiber evaluations. They are especially effective for flexible materials that can be difficult to clamp with traditional grips, helping ensure the sample fails in the gauge length rather than at the gripping point.
4.5K lb. Rope Grip - 20kN
This Rope Grip uses a slightly different design to improve load distribution during testing. The rope is wrapped several times around the drum and then secured in a “figure 4” configuration, which increases friction and helps prevent slippage as tensile force is applied. Rated for capacities up to 20 kN, this grip is well suited for higher-strength cordage and rope applications where secure holding is critical. These grips are designed for use on dual column universal testing machines, allowing the system’s added rigidity to support better alignment and more consistent test results.
10K lb. Rope Grip - 50kN
The 50 kN Rope Grip can handle loads slightly over 11,000 lbs, making it ideal for heavy-duty rope and high-strength cordage applications. While the overall geometry has been reinforced and the design adjusted to support the higher capacity, it still operates on the same proven capstan working principle. The rope is wrapped around the drum to build friction gradually, allowing the load to transfer smoothly into the specimen and reducing the risk of slippage or premature grip breaks during high-force testing.
22K lb. Big Rope Grip - 100kN
These heavy-duty wrap grips are designed for demanding industrial cordage applications such as maritime lines, lifting slings, and crane cables. The oversized rope drum accommodates thick ropes and large-diameter wire, allowing the specimen to be wrapped securely so the load is introduced gradually and evenly. This added control helps minimize slippage and reduces the risk associated with dangerous snap-back when high-strength ropes fail, promoting safer testing conditions and more reliable tensile results for materials built for extreme service environments.