Robertson screwdriver

Part of the series on
Screw drive types
	Flathead ("Slotted")
	Phillips ("Crosshead")
	Pozidriv (SupraDriv)
	Torx
	Hex (Allen)
	Robertson
	Tri-Wing
	Torq-Set
	Spanner Head
	Triple Square (XZN)
This box:  •  • edit

A Robertson screwdriver (also called a square drive screwdriver) is a type of screwdriver with a square-shaped tip with a slight taper (in the same way that flatheads, Phillips, hex, and Torx have flat, ×-shaped, hexagonal, and hexagrammal tips, respectively). Robertson screws are used mainly in Canada, but are growing in popularity around the world, as they are one of the most reliable screwdrivers.

Close-up of Robertson drivers

Canadian P.L. Robertson invented the Robertson screw and screwdriver in 1908. He received a patent in 1909, and later applied for and received other patents. The last patent expired in 1964.

Robertson screwdrivers are easy to use one-handed (i.e., without using the second hand to hold the screw), in fact, when driving a screw one handed, the user can let go of the driver, and the driver will stay put in the screw. They also allow for the use of angled screw drivers and trim head screws.

Close-up of Robertson screw

Robertson had licensed the screw in England but the party with which he was dealing intentionally put the company under and purchased the rights from the trustee thus circumventing Robertson. He spent a small fortune buying back the rights. After that he refused to ever allow anyone to make the screws under license. When Henry Ford tried out the Robertson screws he found they saved considerable time in the production of cars but when Robertson refused to license the screws to Ford, he realized that the use of the screws would not be guaranteed and stopped using them.^{[1] [2] [3]}

Recess dimensions

Robertson-head screwdrivers are available in range of tip-sizes. A given driver's suitability for use with a particular size of screw and recess size is indicated upon its handle according to the following colour code:

Footnotes

References

• Rybczynski, Witold (2000). One Good Turn: A Natural History of the Screwdriver and the Screw. Toronto: Harper Flamingo. ISBN 0-002-00031-8.

External links

• Robertson Inc. official web site
• [1] Robertson screw on CBC's 50 Greatest Canadian Inventions list