Square Drive Screws
![Square Drive Screws](https://www.stevensonplumbing.co.uk/images/cache/Hardware/screws/1000_inch_no8_square_drive_scew_and_head.800.jpg)
Square drive screws and matching Robertson scrulox screwdrivers.
Square drive screws were invented by Canadian Peter L. Robertson over 110 years ago in 1908
The screw head has a deep square recess to take the driver. The screwdriver locks into the screw head so that you can wave it about and the screw will not fall off.
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