Tensile Testing Grips
Tensile grips are used for uni-axial material testing where a sample is pulled apart from two ends. There are many variations of tensile grips for universal testing machines based on the force capacity of the procedure and the specific type of material and geometry. Many of these fixtures can use different types of inserts which can help to secure the sample. Selecting the right combination of grip and jaw inserts is critical to the success of any tensile testing application.
Many tensile tests require that the stress vector is perfectly aligned in the vertical direction. In many cases, a universal joint can be used on the top grip in order to get everything in the same plane for uni-axial testing.
Bollard Grips
Bollard Grips are used on a Universal Testing Machine to perform tensile tests on filament material such as string, thread, wire and yarn. The specimen is wrapped around a bollard or post and then secured with a vise grip mechanism. The term bollard comes from the maritime industry and is used to describe a thick, short post on a ship deck or dock which is used to wrap a rope around to anchor the vessel. There are a few different types of bollard fixtur...
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Bolt Grips
Bolt grips are also known as threaded grips and they are used for tensile testing procedures on bolts, rods, screws and other cylinder type samples. The grips are female threaded in order to match up with the specimen. Either one or both of the grips can be threaded. Quick Change Bolt Grip with Threaded Inserts Samples that have a screw head can be lowered into a special top grip. The head rests on a recessed ledge inside of the bored out tube. The bottom grip is the only one used to scre...
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Fatigue Grips
Fatigue testing grips are used on dynamic universal testing machines to test sample specimens over multiple cycles. These special vise action fixtures are capable of both tensile and compression forces. A solid block is used to backstop the sample and create compression. The sample is gripped laterally by tightening the screws on the side of the fixture. Fatigue testing grips are custom designed and machined to order. They take a few extra weeks for delivery. These grips ...
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Peel Grips
Advanced manufacturing practices such as lightweighting and automated assembly have led to above trend growth in the adhesives industry. In 2016, the global market for adhesives stood at roughly $25 billion USD with 10 million tons of output. As the market has matured, a myriad of ASTM peel testing procedures have been developed in order to test the strength of the manufactured adhesives. The most popular and simplest procedures involve peeling a tape at an angle of 90 degrees or 180 degr...
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Pinch Grips
Pincer and Pinch grips are both used to grab small areas of a sample for a tensile test. These fixtures are ideal for testing end-consumer products because the grip actuation resembles two fingers pinching together and pulling on something. Pinch grips are spring loaded, so the grip exerts a constant lateral force on the sample. The spring can be tensioned in such a way so as to increase or decrease the amount of pinching force. By turning the knob at the end of the grip, the amount of pi...
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Pneumatic Grips
Pneumatic Grips for Universal Testing Machines Overview Pneumatic grips use air to actuate the grip jaws and provide a constant and repeatable lateral force on the sample specimen. There are many different types of pneumatic grips that are used for tensile testing including vise grips, wedge grips, and certain styles of rope grips. Pneumatic grip setups are ideal for production environments with high testing throughput requirements. Using pneumatic tensile gr...
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Roller Grips - Self Tightening
Self Tightening Eccentric Roller Grips are used for sample materials with high elongation such as elastomers and plastics. These types of grips are also commonly referred to as eccentric roller grips or cam grips. Other softer type materials like wood also use these self tightening tensile grips. There are two main types. The first only has one spring-actuated roller cam that presses against a flat metal surface. The other variation is not as popular and uses two rollers and is designed so that ...
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Rope Grips
Narrow or Cylindrical Cord 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 ope...
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Scissor Grips
Scissor Grips are a type of self-tightening fixture used for tensile testing. These grips are ideal for wider/thicker samples of bone, elastomers, foam, plastics, or wood. The Scissor Grip uses a spring to create tension and drive the jaw clamps together. This tensile grip is often chosen because it can open much wider than self-tightening roller grips or wedge grips. The spring tension force is highest when the grip is wide open and smal...
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Shoulder Grips
Shoulder grips are a great solution for a myriad of different types of samples including wire crimps, plugs, and connectors. The term shoulder grip is used to broadly define any grip with a specially designed ledge for a sample to rest upon. The widest part of the sample rests on the shoulder ledge, and then the sample is pulled or pushed from the other side. These types of tensile grips are ideal for testing button heads, bolts, briquets, nails, rivets and screws. These fixtures can also be us...
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Wrap Grips
Wrap Grips are also known as webbing grips or capstan fixtures and are designed for tensile testing of flat cordage - ribbons, slings, straps, tarpaulin, and webbing. The flexible material is wound around the wrapping column and then secured with locking pins prior to the tensile test. These grips are ideal for high-strength textile webbing materials that are used in industrial applications such as shipping and construction. Custom Wrap Grips are also available on request....
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Wedge Grips
Overview: Tensile testing wedge grips are essential fixtures for securely holding specimens during high-strength tensile testing on a universal testing machine (UTM). These mechanical wedge grips are self-tightening, meaning the clamping force automatically increases as the tensile load is applied, ensuring the sample remains securely in place throughout the test. Each wedge grip includes interchangeable grip jaw faces designed for different specimen geometries. Flat samples typically use...
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Vise Grips
Vise Grips are the most basic type of grip used by a Universal Testing Machine(UTM) for tensile testing. There are two main types, Low-Profile and U-Style. The Low-Profile version is lower cost but has a limitation on the width of the grip face inserts. The U-style is more standard and can accommodate larger jaw inserts. Two versions of the screw action also exist. The single action style has one fixed jaw and one moveable jaw that is tightened with a screw mechanism. Dual action uses two m...
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