Adapters for Universal Testing Machines
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Overview:
There are several different types of adapters, brackets, fixtures and mounts that are needed to accessorize a materials testing system. Identifying which adapter you need is easy and Universal Grip can help fit grips onto any testing machine.
This page attempts to cover as many of the standard adapters as possible. There are many potential combinations of sex, sizes, and shapes, however UGC has standardized on a male eye end design which attaches to the female coupling on the grip using a clevis pin and jam nuts. Often times, just one set of adapters can unlock your machine to our complete product line.
Universal Grip has the capacity to design and machine custom adapters and fixturing to meet your exact needs.
How they Work:
The standard grip attachment uses a clevis pin style adapter mechanism. The end of the grip fixture is typically female, with most having a diameter of 5/8" or 1.25" (Df). The female end receives the male eye end and the whole thing is then secured with a locking pin. There is still a bit of play in the locking pin so jam nuts are used to tighten everything and lock it into place. The jam nuts are tightened with a special wrench called a spanner wrench.
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Key Measurements:
There are 3 key measurements that are necessary for specifying adapters:
1. The outside diameter of the eye end. (If it is female, then ID)
2. The diameter of the pin hole, or the locking pin.
3. The distance from the bottom of the adapter to the center of the pin hole.
Standard Eye Ends
The Standard Eye ends are Male-to-Male and are used to attach a grip with a load cell. Two jam nuts are used to tighten the assembly and reduce any potential slippage. Different sizes are available based on the load of the applications and the threads on the Load Cell.
Downsize Eye End
The Downsize Eye end is used when the application calls for a smaller sample jig. Most dual column machines use a 1.25" eye end and the adapter pictured downsizes it to a 5/8".
Male Screw Thread to Male Eye End
Most load cells and force gauges will use a female scre thread pattern. Based on the screw thread callout, an appropriate M-style screw can be fitted. The other side has a standard male eye end of size 5/8", 1 1/4", or higher.
Female Screw Thread to Male Eye End
It is common for a tensile tester to just use a protruding bolt on the base plate or also on the top cross-head. By measuring the thread callout, an F-style adapter can be provided. The other end has the eye end of standard sizes 5/8", 1 1/4", or higher.
Base Plate
The base plate is typically mounted on the bottom of the UTM, opposite the load cell. This base plate is male, however female base plates are also available. The screw pattern of the base plate must match the drill hole pattern which is at the base of the tensile tester.
Universal Joint
Universal Joints are used for many tests that require self alignment. There are two sets of ball bearings that allow the assembly to move freely in all directions. There are several types of universal joints available depending on capacity and the degree of freedom. These types of adapters are also commonly referred to as cardan joints.
Chain Adapter
The Chain Adapter links a grip or fixture to the load frame through a short length of chain, so the specimen can self-align and bending loads are kept out of the test.
Grip Adapters by Testing Machine Brand
Universal Grip grips and fixtures use a female coupling: 5/8 in (15.8 mm) with an 8 mm pin, or 1.25 in (31.7 mm) with a 12.7 mm (1/2 in) pin. These adapters connect them to the frame you already own:
Instron: clevis pin couplings. Smaller benchtop frames often use a 12 mm coupling with a 6 mm pin, which our small adapter fits. Larger frames commonly use 31.7 mm with a 12.7 mm pin, a direct fit for our large grips.
MTS: threaded or pinned connections depending on model. Large frames commonly share the 31.7 mm / 12.7 mm pin coupling, and we make threaded adapters for servo-hydraulic load cells and actuators.
Shimadzu: pinned couplings that vary with frame capacity. Send us the coupling diameter and pin size and we will match it.
ZwickRoell (Zwick): ZwickRoell pin connections that vary by capacity. We make adapters from these to our standard eye end.
Tinius Olsen: pinned or threaded connections depending on model and age. A photo and a few measurements are usually enough to confirm fit.
Mark-10 and force gauge stands: threaded connections, typically #10-32 or 5/16-18. Our male and female screw-thread-to-eye-end adapters fit these.
Not sure what you have? Send the coupling or shank diameter, pin diameter or thread, frame model and load cell capacity through our contact page. For more detail, read the Tensile Grip & Fixture Selection Guide and Our 3 Most Common Grip Adapters, or browse our tensile grips.
Grip Adapter FAQ
Will one set of adapters fit your whole grip line to my machine?
Usually, yes. Universal Grip standardized on a male eye end that pins into the female coupling on our grips, so one set of adapters for your frame often unlocks our complete product line.
Do adapters reduce the capacity of my test setup?
A load train is only as strong as its weakest part. We size adapters to match the grip and frame capacity, and we keep them as short as possible to limit misalignment.
Can you make a custom adapter?
Yes. We design and machine custom adapters, brackets and fixtures in-house when a standard adapter will not fit your frame or load cell.
Instron, MTS, Shimadzu, ZwickRoell, Tinius Olsen and Mark-10 are trademarks of their respective owners. Universal Grip is not affiliated with these companies; names are used only to describe compatibility.