Allen wrench sizes can be surprisingly easy to mix up, especially when you’re moving between inch and metric fasteners. Having a clear size chart on hand saves time, prevents stripped sockets, and helps you choose the right tool the first time.
| Metric (mm) | Imperial (inch) | Common Application |
|---|---|---|
| 0.7 mm | 0.028″ | Precision instruments, eyeglasses |
| 0.9 mm | 0.035″ | Small electronics, watches |
| 1.5 mm | 1/16″ | Small electronics, RC models |
| 2.0 mm | 5/64″ | Small appliances, fixtures |
| 2.5 mm | 3/32″ | Bicycles, small machinery |
| 3.0 mm | 1/8″ | Furniture, bicycles |
| 4.0 mm | 5/32″ | Power tools, bicycles |
| 5.0 mm | 3/16″ | Automotive, machinery |
| 6.0 mm | 1/4″ | Automotive, industrial equipment |
| 8.0 mm | 5/16″ | Heavy machinery, automotive |
| 10.0 mm | 3/8″ | Industrial machinery |
| 12.0 mm | 1/2″ | Heavy industrial applications |
MISUMI USA carries a wide range of allen wrenches and hex keys. For more insights about allen wrenches, and other manufacturing related articles be sure to check out our blog, and articles like – What is an Allen Wrench?, 7 Quick Facts About Allen Wrenches and more.
Disclaimer:
The content on this webpage is for informational purposes only. MISUMI makes no guarantees, expressed or implied, regarding the accuracy, completeness, or validity of the information. Performance parameters, tolerances, designs, materials, or processes should not be assumed to reflect third-party suppliers’ or manufacturers’ deliverables within MISUMI’s network. Buyers are responsible for specifying their part requirements