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Adapters for Universal Testing Machines



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. 














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.





tensile tester adapter
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 adapter
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 Threaded Adapter
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 Threaded Adapter
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.  

tensile tester base plate
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 for tensile testers
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.

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