Breaker Bar Torque Calculator — Torque Without a Torque Wrench

Stuck on the trail with a fastener that needs torquing and no torque wrench in the kit? Torque is just force multiplied by distance, and your body weight is a force you always have with you. Enter your weight and the target torque, and this calculator tells you how far along a breaker bar to stand so your weight applies the right torque to the fastener. It also earns its place in the workshop! Some fasteners, like the hub nut on sealed-bearing vehicles such as the Discovery 2, are specified beyond the range of most torque wrenches, and this is a simple way to hit that figure.

How to use

1. Enter the weight of the person who will stand on the breaker bar, and the target torque for the fastener.
2. Measure the calculated distance along the breaker bar, starting from the centre of the head (where the socket attaches), and mark it.
3. Put the socket and bar onto the fastener, with the bar as close to parallel to the floor as you can ‐ angled slightly upwards is preferable.
4. Stand gently, one-footed, on the bar with the middle of your foot on the mark. Do not jump on or bounce.
5. The bar may need moving back to parallel a few times as the fastener turns. Once it stops turning, gently step off.
6. Done for now ‐ but check and re-torque with proper equipment as soon as it is available.

Use a calibrated torque wrench whenever the target figure is within its range, and always check the correct torque specification for your vehicle. For critical fasteners, re-check with proper equipment as soon as it is available.