Screws #12 - 24 Floorboard
 

I am putting in the floorboards and will put back the seat assembly in a '31 coupe moveable track. The suppliers note #12-24 screws are used. Years ago I took out the floorboard screws and kept them in a bottle. I cannot get them back into the D-clips in the floor. I could not get the original screws into the D-clips. I pulled out a 12-24 tap and ran the tap through the D-clips. I checked the thread pitch and it was 24. I have some replacement screws and they are exactly they same size and pitch and also will not fit into the floor or seat support. Why don't these screws that are supposed to be #12-24 not fit into the support clips? What am I missing?


Vic

Re: Screws #12 - 24 Floorboard
 

Use thread guage and tap to ascertain
If you’re like me “years ago” could be culprit
That’s what they’re suppose to be

Re: Screws #12 - 24 Floorboard
 

Yup, I agree. Try running the screws in without the floorboard to make sure the D-nuts are canted the right direction. I’ve had the opposite issue: D-nuts stripped.

Re: Screws #12 - 24 Floorboard
 

Hello, after checking the fit into the d nuts , check clearance and alignment of holes in floor boards, wood holes may not be fitted to the d nuts.

Re: Screws #12 - 24 Floorboard
 

Are you sure you have 12-24 screws and not 14-24? Same thread pitch but slightly larger diameter.

Re: Screws #12 - 24 Floorboard
 

Thanks katy, I did not know there is such a thing as 14-24. The screws could be a 14-24 but do not fit in a 12-24 hole. Next trip to the hardware store I will buy some 12-24 screws and see how they fit, if the local hardware stores carry that size.


Vic

Re: Screws #12 - 24 Floorboard
 

If you cannot find them at the local hardware store, McMasters-Carr has them. Easy to use web site and fast delivery, but pricey.

Re: Screws #12 - 24 Floorboard
 

If it's the floorboard screws you are looking for, best to get them from one of the Model A suppliers, where you can get the special washers that go with the screws.

Re: Screws #12 - 24 Floorboard
 

I could not find 14-24 screws on McMaster-Carr or Bolt Depot. I doubt your local hardware store will carry them. You sure you are not referring to the next size larger than 12-24, which would be ¼"-24?

The ones Bratton's sells are 12-24 https://www.brattons.com/FRONT-FLOOR...uctinfo/28090/

Re: Screws #12 - 24 Floorboard
 

Check Bratton's, Snyder's, or Bert's. They sell as a kit with the right type washers.

Re: Screws #12 - 24 Floorboard
 

Hardware stores sell 12-24, but probably only philips head. Even the vendors' screw is not taper thread like the original. The head is also smaller and thicker.

Re: Screws #12 - 24 Floorboard
 

Really? I hadn’t noticed that.

Re: Screws #12 - 24 Floorboard
 

I believe all Henry's 12-24 were taper thread. Heads were flatter and wider than what you find today, also.

Re: Screws #12 - 24 Floorboard
 

But running a tap down obviates the need?

I suspect any taper thread here was to work with the D-nut - and present a screw which didn't need any sort of "lockwasher" or similar. The dished washers by themselves wouldn't keep the screw from backing out.

I think the "kits" available are straight thread - at least mine was 40 odd years ago.

Loctite is a force today. I would go blue unless you have a special need to tear out the D-nuts.

Joe K

Re: Screws #12 - 24 Floorboard
 

14-24 is an obsolete thread size (A.S.M.E.), used "back in the day". Some people think 14-24 is the same as 1/4-14, but it's not. #14 is slightly smaller than 1/4".
#12-24 screws are .216" diameter, #14-24 are .242" and 1/4-24 are .250"

Re: Screws #12 - 24 Floorboard
 

I can relax - I’ve learned something new today!

Re: Screws #12 - 24 Floorboard
 

They're called bugle head.

Re: Screws #12 - 24 Floorboard
 

Thanks for learning me on that. I have never heard of or can find anyone that carries a 14-24 screw.

Re: Screws #12 - 24 Floorboard
 

So, what is the correct size? #12 or #14?

Re: Screws #12 - 24 Floorboard
 

Good afternoon...Do get a kit from one of our suppliers mentioned above. Or, I like Arizona Model A...the bolts and washers come together. Also drill out the floorboard holes to 5/16 inch to give a bit of flex to get the bolts started...Call Sammy at 480-782-0266. Tell him Ernie sent you. Ernie in Arizona