Robertson Drive Bit: #2, 2 inches
Although the terms "square drive" and "Robertson drive" are often treated as the same, there is a big difference - Robertson drives and Robertson screws have a slight taper to the square recess and a square drive and screw does not.
Robertson drives were invented by Canadian Peter Robertson around 1906 and are very popular and common in Canada, but not so much elsewhere.
The advantage of using a Robertson drive with a Robertson screw is that the screw will "cling" to the driver, allowing one handed driving and virtually eliminating slippage common with drives such as Phillips drives.
These #2 Robertson drive bits fit our Rob Cosman screws with their duo Quadrex heads perfectly. While a #2 square drive will also work, it doesn't fit the screw head perfectly like a Robertson and will not give you the "cling" feature.
We highly recommend you use Robertson Drives with our Rob Cosman screws.
Great screws and drivers- I wish I had discovered these years ago. I have lost count of the number of times I have dropped a screw from my drill driver or even the screwdriver, up on a ladder or at my bench. These screws eliminate that problem. See Robs Demo with the screws on YouTube. I tried it myself because I really didn’t believe they would stay on the driver that well. I will only be using these types of screws from now on. James Dietrich.
The sizes and varieties make these perfect for my wood working. The special head design really works well and aI never seem to strip a head anymore.
Very good product and service was excellent. I'll be purchasing from you again. Keep up the great work.