The Torque Tester


Model Description

This training aid provides an example of what the students already know intuitively about mechanical advantage and applied moment.  By using a dial torque wrench, units and physical measurement are readily observable and subject to discussion. This demonstration should take 5 minutes.

Engineering Principle

M = F \cdot d_{\perp}

What You Need

Item Quantity Description/Clarification
Secure Bolt (Fig. 1, left) 1 Welded to a metal bracket or secured in a block of wood fastened to a desk.
Dial Torque Wrench (Fig. 1, right) 1 If you have an automotive ME program, check to see if they have one to borrow.

Fig. 1

How It’s Done

In Class: Start the class with the “Strongest Student Competition.”  The “Torque Tester” is the tool to judge the competition and the class elects the toughest member of the class.  That person comes forward and is given the rule that his/her hand must be placed so that it touches the socket part of the torque wrench (decreasing their mechanical advantage) (Fig. 2, left). After all, we don’t want the strong student to flip the desk over through brute strength.  A judge is selected from the class to read the dial on the torque wrench.  A reading is obtained.  The instructor then selects an obviously less strong member of the class.  The second student is told that they have the freedom to grab the wrench anywhere they choose (Fig. 2, right). The strong student records the reading.  Inevitably, the “weaker” cadet triumphs and the class enjoys a laugh.

Fig. 2

Did you try this? Comment below to let us know how it went.

Cite this work as:

Tom Messervey (2019), "The Torque Tester,"

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