Torque Wrenches Explained: Types, Accuracy, and Best Use Cases
Torque Wrenches Explained: Types, Accuracy, and Best Use Cases
A torque wrench applies a specific amount of rotational force to a fastener. Using one prevents both under-tightening (loosening) and over-tightening (thread stripping). Here is a practical overview.
Common Types
- Beam torque wrench – simple, durable, and inexpensive; readings come from a deflecting beam. No calibration drift but harder to read.
- Click (micrometer) torque wrench – the most popular type; emits a audible click at the set torque. Easy to use and accurate.
- Digital torque wrench – displays torque on a screen, often with alerts; best for precision work and data logging.
Accuracy and Calibration
Most consumer and professional click wrenches are accurate to about ±3–4% of the set value. For critical applications, calibrate annually or after heavy use, and always store the wrench at its lowest setting to relieve spring tension.
When to Use One
Use a torque wrench whenever the manufacturer specifies a torque value – cylinder head bolts, wheel lug nuts, brake calipers, and bicycle components are common examples. For free-spinning fasteners, a standard ratchet is sufficient.
Conclusion: A click-type torque wrench is the best all-round choice for workshops, while digital models suit precision and regulated industries.