Robertson Head screws in 1931 CD8 roadster?

[Gunsmoke]

My '31 CD8 Roadster came to me with the steel folding side irons but very little left of the original wood bows which would have been screwed to the side irons. The only pieces left were about 3" of the very ends of the middle bow. It appears original, and was screwed to the side iron with a rusty #10 Robertson head screw! My car was assembled in Windsor Ontario Canada, and I understand from some reading that Robertson head screws were a Canadian patent from about 1909, and Ford used them in their Canadian production, but not in USA. Am I right to suggest likely Chrysler plant  in Windsor also used Robertson head screws rather than the more common slotted screw?

[keiser31]

Could you please tell me where you got the 1931 Dodge coupe seat?

[Spinneyhill]

If you look in the Standard Parts section of the parts manual, it calls up most fasteners by size, material and finish. There are no Robertson head screws in a Dodge Brothers up to 1933.

[Gunsmoke]

k31 sent you a PM.

[keiser31]

Thanks.

[Rusty_OToole]

Robertson screws were a Canadian invention first made in 1908, patent issued 1909. Widely used in Canada especially in manufacturing since they were so much faster and easier to use than the common slot type.

 

Ford and GM refused to use them at least in the US because, being patented, could only be bought from Robertson and were slightly more expensive than other screws. So they went with the inferior Philips type starting in the 1930s as they were cheaper.

 

So, it is possible they were used in the Canadian factories but not in the US. Probably because they were more price competitive in Canada.

[Spinneyhill]

They are widespread now. Has the patent expired?

[Rusty_OToole]

Patents last 17 years so a 1909 patent expired in 1926. There were later patents, the last expired in 1955 according to the Robertson company website.

[Guest]

The only head equal to or maybe slightly better than "Robertson" is "Torx".  Who knows if they will last as long as Robertson. 

[Spinneyhill]

8 hours ago, Rusty_OToole said:

Ford and GM refused to use them at least in the US because, being patented, could only be bought from Robertson and were slightly more expensive than other screws. So they went with the inferior Philips type starting in the 1930s as they were cheaper.

 According to the Robertson web site, they were used on Model Ts and As in Canada. They saved 2 hours per Model T in build time. They stopped using them because Robertson would not license Ford to make them. Henry decided security of supply was dodgy and went to other fasteners.

[a sell]

In the late 70s my brother showed me the remains of a Model T, or a Model A sedan that was in the woods near Prince George.  It had nickle plated brass Robertson screws.   I think I got one or two out of it.  At that time he thought they were introduced in the 30s and speculated they were a repair, but where the screws were sure looked original.  

[Hudsy Wudsy]

For those who don't recognize them by their name (like me):

 

[lozrocks]

I had to google it. Never knew they were called Robertson head before.

 

[Rusty_OToole]

As a Canadian I long believed they were used in Canada only, and rarely anywhere else. Remember hearing of Canadian companies who used the screws in their products, and had to include a screwdriver with every order because they were unknown in the US and elsewhere. Can anyone outside Canada confirm or correct?

[Bloo]

When vacationing in Canada in 1978, I noticed Robertson screwdrivers in all the hardware stores. Here in WA, USA Robertson screws literally did not exist. It was an obscure thing here like double-d, and I had never seen a driver.

 

The idea has taken off like crazy, thanks to cordless drill-drivers. To this day, almost nobody here knows they are called Robertson screws.