Screwdrivers.

Chris Pearson:

John Peckham:

The head is female as the bit inserts in to it, the screw is male and the thread is metric. 

Ah yes, but what about male-headed screws which need a female driver? Yes, they do exist.

Or the security-torx heads that have an additional 'protrusion' into the recess from the screw head - that fits inside the bit...


   - Andy.

Chris Pearson:

John Peckham:

The head is female as the bit inserts in to it, the screw is male and the thread is metric. 

Ah yes, but what about male-headed screws which need a female driver? Yes, they do exist.

Or the security-torx heads that have an additional 'protrusion' into the recess from the screw head - that fits inside the bit...


   - Andy.