Below you will find answers to our most often asked questions. If you are unable to find your answer, please feel free to contact us.

How often do I need to recalibrate my Skidmore and how do I do it?
We recommend recalibration every year, however frequency of calibration varies by industry and use.  The construction industry typically requires annual calibration due to the critical nature of their work.  Other industries, such as aerospace are even more stringent. To send your unit in, please click here and include the calibration form with your unit.

What's the difference between torque and tension?
Skidmore units were developed for this very question! In the simplest terms, torque is a force applied about an arm.  For example, pulling on a one foot long socket wrench with 50 lbs of force will produce 50 ft/lbs or torque applied at the socket.

Bolt tension is force that wants to stretch the bolt.  Turning the nut in a bolted joint creates this tension.  The resulting tension, or stretching of the bolt, creates the clamp force that keeps the joint together.

Torque and tension are related primarily by friction.  Tests have shown that 90% of the energy used to tighten a bolt is to overcome friction.  Controlling friction is the critical element to successful bolt installation because small variations in friction can cause large changes in bolt tension.

We also make units that are designed to measure torque. These units are designed to test torque wrenches, impact wrenches, etc. In these units, we provide you with the torque number that your tool is producing.

So, how come I can buy a Skidmore calibrator that measures tension and use it to test my impact wrenches?
We developed a method for testing impact wrenches using base mounted versions of our torque/tension calibrators. THESE UNITS DO NOT MEASURE TORQUE. They are designed to provide a method for accurately comparing the output of impact tools. Our test bolt assemblies are manufactured to precision standards.  When used correctly, they present the same joint to the impact wrench for thousands of tests.  Variations in the gage reading in these tests will be due to the tool itself.   Conversion to torque can be made by using a simple calculation. (divide by a factor determined by the bolt size you are using). For more details, see the Tension to Torque Conversion Chart.

I'm just starting a budget for a unit, what is the approximate cost?
The size of our units varies greatly, so the cost can change.

For testing bolts, the range is approximately as follows: $1,000 to $3,000 for the unit plus $100 to $250 per bolt diameter you will be testing. You may also need to purchase additional plates and bushings for smaller length bolts.

For testing wrenches: the range for the unit is approximately the same and the test bolt assemblies range from $160 to $600 depending on size.

For rotational capacity testing, our units start at $30,000.