Metric to Imperial Screw Converter

Quick answer

Screw size conversion maps metric diameters to closest imperial threads for stocking and repair bins.

Closest does not mean interchangeable—pitch and class still must match the joint.

Use the converter below, then open individual bolt size pages for tap drill size and hex data.

Choose a direction and screw size to see the closest common equivalent instantly.

Follow with tap drill size checks after you pick a closest match.

Open M6 bolt size pages for detailed drill and hex columns.

Bolt & screw size reference pages — detailed specs for M6, 1/4-20, and more.

This tool maps common metric screw sizes to their closest commonly used imperial thread equivalents for practical workshop use.

Yes. Results update instantly when you change direction or select a different screw size.