The Stovebolt Site Forums The Shop Area General Truck Talk Clutchhead/Phillips head

I am taking apart my latest find a 1941 GMC COE. I was surprised to find only Phillips head screws, not just a few, all of them, from the trim all the way to the large door hinge fasteners and even the big ones that hold the lower cab together. At first I thought maybe they were replaced during a rebuild but I am almost finished with disassemble and have yet to find a clutch head screw. Even the little guys under the ash tray. My 41 GMC pickup has them need to check my 45 panel. What gives? Dave

Maybe it was made in Canada? The only clutch head screws I found was in the original vacuum operated wiper motor.

When I restored my 47 3600 Chevy, almost every screw was clutch head. I don't like them, at all !!! If a screw was to strip it's head it was a clutch head screw. I replaced them with SS Philips screws. Luckily They were more of a pan head and a small vice grip could grab them, I only broke two bolts off in the rebuild of my truck.

I once had a Model A body that had all square recess head screws. They weren't very common back then, but I did some research and found that Robertson (square recess) screws were a Canadian invention and that's where that particular body had been assembled. Henry Ford started using them on the Model T, at their Windsor, Ontario plant. The patent for Robertson screws expired in 1975, and they became more common.

I also found this bit about clutch drive screws (patented by a guy named Joseph F. Fieg (so it might have been called the Fieg screw.):

Because of the very positive engagement between driver and screw, it was well suited to mass production and was adopted by Chevrolet for their cars, trucks and buses from the 1940's through the 1950's. As a result, it was sometimes referred to as a "Chevrolet screw." It could also be found on older tractors, where it was used to secure sheet metal parts. (In contrast, General Motors adopted the Phillips screw, patented in 1936, first on the 1936 Cadillac and later for their trucks.)

On this blog site.. I added the emphasis in bold.

Around 1964 I owned a 1936 Ford. I was the second owner. It had been assembled using nearly every variant of screw head you could imagine...some straight slot, a few with square recess head screws, a few had two small holes diametrically opposed (which were almost impossible to remove as they always rusted/seized aggressively) and a couple of others. I don't recall any original Phillips head screws but a few had been replaced with Phillips screws (probably by the dealership or by a local mechanic). I finally decided Ford handed whatever screws they had handy to the various assembly stations and that's what they used. Otherwise I can't imagine why so many various screws were used.

Ford's corporate philosophy was heavily influenced by Henry Ford's well known thriftiness. The company was known for using up whatever they had on hand and whatever was cheaper. They weren't about to throw away any old fasteners that were super-ceded by newer , better ones. That all changed during and after WWII.