MTFCA Forum

Unwitting, like a noob, I posted this picture on social media. I was immediately 'schooled' about the incorrect Phillips head screws on my T dash. It's a US car. So I did some learning, and believe that this is now correct. Is it? TIA

With regards to the types of screws your chart is correct. However, screw heads are also different over time, those shown are flat head screws. As to the 26-27 ignition switch, you should have oval head screws, they should be nickel plated and slotted for a flat blade screwdriver.

The only place I've ever found Robertson screws on our Canadian T's in Australia are the 4 holding the steering wheel rim to the spider.

I had a '15 or maybe later Runabout body with Robertson screws on the door hinges, both wood and machine screws.
Rich

My 1915 tourer had many Robertson screws throughout the timber frame. There were both slotted head and Robertson head screws used on Canadian 26-7 models to hold the dash in. They were nickel plated brass machine screws, correctly termed raised countersunks. Can someone explain how a screw can have an oval head?

Allan from down under.

Can someone explain how a screw can have an oval head?

It's the common name, but domed or convex head would be a more accurate description.

I suspect that Domed, Flat and even Pan Head machine screws are used in various locations, right? For example, the transmission cover would use Pan Head screws. The door jams use Flat Head screws. And the dash bezel would use Domed head screws. Am I correct?

Steven, yes, some screws are round head, some flat head, some oval head, depending on application and location. Trans cover is round head, door jamb is flat head, most trim screws are oval head. Your Home Hardware in Canada uses the term oval head same as USA, suspect domed head is something else entirely. I cannot think of any pan head screws used on a Model T.

I borrowed this picture from the internet without permission.
first is oval head, second is flat head, third is round head, last is pan head.

Maybe this is a better diagram? What do you think?

You got it Steven.

Interesting post about vintage screw types.

When I restored my 24 T Coupe I noticed all of the interior trim screws were nickel plated slotted oval head screws. I also had a 25 Fordor sedan I sold years ago and it also had nickel plated oval head interior screws.
I’ve wondered if Ford left the screws unpainted or if they were painted after the closed cars interiors were installed and then spray painted.

The artsy Venn diagram implies screws introduced after 1935 were used in assembling Model T's that went out of production in 1927? For that diagram to be correct you would need at least one additional axis to show time and probably a fourth to include all the shapes, domed, pan, along with the made-up names, etc,

Ford used a fillister head slotted, on the mag posts. High on the early ones, and not so high on the later ones. As I recall the late style is also used on the generator.

Larry, those are called cheese head screws here, like a round of cheese. That's a much more accurate description for the shape than oval head is for raised head countersunks. I have come across some of the mag post screws you describe as thicker for the earlier cars. Might they have a slight crown to the head as well? If that's the case, to be consistent, I guess you guys would call them oval head fillisters.

Allan from down under.

As for Canadian, I restored a 26 Fordor from what I believe to have been an original car. The visible screws on trim, dash, windshield hardware, etc. were all oval head nickel plated Robertson wood screws and machine screws. Other screws were all Robertson flat head screws, not painted unless the assembly was painted prior or after final assembly, such as the door hinge screws.

DJPeterson wrote: ↑

Fri Jan 14, 2022 8:55 pm

As for Canadian, I restored a 26 Fordor from what I believe to have been an original car. The visible screws on trim, dash, windshield hardware, etc. were all oval head nickel plated Robertson wood screws and machine screws. Other screws were all Robertson flat head screws, not painted unless the assembly was painted prior or after final assembly, such as the door hinge screws.

Thanks! This makes it clear that my Venn diagram seems to be correct regarding Canadian cars. As others have suggested, I may try to add to it to include head shape information as well.

jab35 wrote: ↑

Fri Jan 14, 2022 10:12 am

... Venn diagram implies screws introduced after 1935 were used in assembling Model T's that went out of production in 1927?

.
I don't understand. I think that the Venn diagram correctly shows that US Model Ts use only slotted head screws, and post 1934 Ford's use both slotted and Phillips head screws. Am I misunderstanding something?

jab35 wrote: ↑

Fri Jan 14, 2022 10:12 am

... you would need at least one additional axis to show time and probably a fourth to include all the shapes, domed, pan...

I'll think about how to indicate time and/or head shapes... But I am not sure where I can find more precise timeline info regarding screw types and shapes.

those are called cheese head screws here, like a round of cheese. That's a much more accurate description for the shape than oval head is for raised head countersunks

Seems to be English language and what the trade calls these type of machine or wood screw head types.

Here is a chart with pretty good descriptions in use today.

Back in Model T days of course, other terms were used to describe the typical 'Oval' head screw, the term of use was French head.
See the description for the counter sink in the Ford ignition switch plate factory print, used on the first wood dash cars, the call out is French head for that Oval head screw.

Would the circled head styles comprise all of those originally used on Model T?

and post 1934 Ford's use both slotted and Phillips head screws.

Regarding Ford use of Phillips head fasteners, that began according to some early V8 car blogs, to be in the 1941-1942 era. A Restoration Book on 1940 Fords stated no Phillips screws were used anywhere.

These Phillips were used by GM for auto use, earlier use was likely with US aviation production.

"Henry F. Phillips, of Portland, OR, invented the X-shaped socket head screw for car makers who needed a screw that could be driven with more torque and that would hold more tightly than slotted screws. Car makers also needed a screw that would center quickly and easily, and could be used efficiently on an assembly line.

The invention was initially rejected, but eventually accepted by the American Screw Co., who in 1936 persuaded General Motors to use the Phillips head screw in manufacturing Cadillacs. Phillips lost the patent to his eponymous invention in 1949."

Steven, the fillister you show with the domed top is likely the early type I mentioned when Larry posted about mag. post screws. The later ones, according to Dan's post, would be flat fillisters.
Dan, the round countersunks, without the driving slots, were used by Duncan and Fraser on the top and bottom of their cast brass door hinges. They are a beast to remove if the nuts are rusted. I have no idea why they were used. They are flush with the hinge, but so are the two countersunk slotted woodscrews between them, so it can't be just an appearance thing. Go figure.

Anyone, what is the origin of French head for what you call oval heads? It is non-descriptive, like filliser, but at least it is not inaccurate like oval head.

Allan from down under.

From my bit of research, and from feedback provided here, I have arrived at these two diagrams to describe early Ford screw heads. Note that naming conventions may differ... And I have rev'd the diagrams, since, I expect, someone will correct me and I will need to update these further.

If I were a first-time observer of the diagram and chart below it, without the benefit of the discussion that preceded it all, I would have the following questions:
1. In the Venn diagram the intersection of the three screw head types is labeled 'slotted', the diagram title "Early Ford Screw Heads" but including the Model T era and US Made Fords (~1940) implies an evolution of screw heads over time from the beginning of the Model T to ~1940, so maybe Rob and Phil pre 1927 are the genetic parents of Slotted ~1940. From the discussion earlier in the thread, I think the diagram is meant to show "Screw Head types used by Ford in Assembling the Model T". Of course if Philips wasn't used, that Venn would have only two categories. A Venn showing "Screw Head Types used in Original Factory Assembly AND by Those who owned, repaired, modified, improved, restored (etc, etc,,,,) these Model T Ford cars up to and including the present date" would be much more complex, and much more interesting. I believe Martyn Vowell might need to be consulted to pull that one off.

2. The early heads profile is good, again the timeline of use of the various types in Ford Factory manufacturing would interest me. And are only sheet metal fasteners considered or are 'Screw and Bolt heads' included? And slotted, Robertson, Philips, torx, etc? Since this began as a Model T fastener thread, I'd respectfully suggest highlighting the Model T specific ones a different color, 'Pre-1930 could include some not used in the manufacture of the T, but certainly all of them and more have been used to keep the cars going since, and in the manufacture of replacements parts we all value.

FWIW, Respectfully, jb