Question about fasteners

Ric,

Those Robertson screws sound like what is used on RVs.

Hi! I like the story about Mr. ? Butler who I met at the factory in 1952. He made a new top for the phaeton I didn't find for another 16 years. It cost me $19.95! His grandson told me (on one of my videos) that he asked his grandfather whether they lined up the heads of the screw slots in the same direction. His answer, " I don't know about the other guys, I just spit 'em out of my mouth and bash them into place with a tack hammer."!
Up here in the wild north, Canada, we are proud of our Robertson head screws! They are great for foiling US types who covet our accessories. They are square holes of varying sizes. Only used on Canadian made Cords Happy Thanksgiving! Ric.

I once heard the benefit of the Posidriv screw and screwdriver was that it allowed the screw to be held onto the screwdriver even when positioned horizontally. This was a big plus on assembly lines. I think GM used them a lot in dash assembly but not sure during which years.

Anyone not familiar with Posidriv screws and screwdrivers will mistake them for a Phillips type. There is a slight shape and style difference, but otherwise very similar looking.

-Maurice

Henry F. Phillips (1890 - 1958) was a businessman from Portland, Oregon and inventor of the Phillips-head screw and screwdriver. His inventions built on an earlier concept credited to the inventor J. P. Thompson.

The importance of the crosshead screw design is its self-centering properties, useful on automated production lines that utilize powered screwdrivers. Phillips' major contribution was in driving the crosshead concept forwards to a point where it was adopted by screw makers and automobile companies.
Phillips did get the patent, mostly because the fastener was self centering in high speed manufacture that would not be of much concern the handmade car like Auburn was making.

Although he received patents for the design in 1936 (US Patent #2,046,343, US Patents #2,046,837 to 2,046,840), it was so widely copied that by 1949 Phillips lost his patent.

The American Screw Company was responsible for devising a means of manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept since it calls for a relatively complex recessed socket shape in the head of the screw - as distinct from the simple milled slot of a flathead screw.

The Phillips Screw Company and the American Screw Company went on to devise the Pozidriv screw, which differs from the Phillips in that it is designed to accommodate greater torque than the Phillips

I saw this question. I thought phillips were developed later than 1936, where there any phillips used at the Auburn plants ? I have not seen them in prewar GM cars. This was at the www.classiccarclub.org site

Q: Are Phillips Head screws OK on Classic Cars?

A: That depends on which Classic you?re talking about. Phillips head screws were introduced in 1936 and were first used on some General Motors automobiles in the 1936 model year. This doesn?t mean that Phillips Head screws are acceptable on all 1936 and later Classics. For instance, Packard didn?t use them until 1938, and you won?t find them on any Classic Era Rolls-Royce or Bentley motorcars. The Club?s viewpoint is that the type of screws used in a proper restoration shall be the same as those originally found on the car. If you aren?t absolutely sure, you would make no deduction. If you feel a deduction is in order, take care to make it under the proper authenticity area and follow the entire authenticity deduction procedure which includes discussing the matter with your Team Leader and having him initial any authenticity deduction you make.