An open-end wrench has parallel-sided jaws that fit snugly on nuts and bolts. Choose the correct jaw size.
Typical applications
- General-use wrenches turn nuts and bolts with flat, parallel faces. Pipe wrenches instead grip round objects.
Advantages
- An open-end wrench has open jaws, while a box-end wrench surrounds the fastener with a notched loop.
Specifications to check
- Choose the correct jaw size to avoid slippage. The jaws should contact the nut or bolt fully, without tilting.
Limitations
- Do not use a wrench on moving machinery. Do not extend its handle with a pipe for extra leverage.
Buying considerations
When buying an open-end wrench, discard models with spread jaws. Instead, choose the correct type and size rather than inserting a shim to improve fit.
Safety & limits
- Use eye protection where flying particles or falling debris are a hazard. A face shield must be worn with safety glasses or goggles.
Sources & further reading
These links document the information used in this article. Manufacturer specifications and source research are not hands-on test results or an endorsement of a purchase.
- CCOHS: Open-end wrench
Reference checked 2026-10-29