Topic: Screw sizes


westgateblvd    -- 07-19-2019 @ 3:29 AM
  I bought some NOS 1937 tail light stands. I would like to know what size screws hold the stands to the fenders. Thank You


1937sedandelivery    -- 07-19-2019 @ 7:49 AM
  Hello,
This attachment should help you.
To answer your specific question, the bolt size is 1/4"-20 x 5/8"
gregg

This message was edited by 1937sedandelivery on 7-19-19 @ 8:25 AM


therunwaybehind    -- 07-19-2019 @ 8:54 AM
  Not wishing to quibble but the bolt in the photo appears to be a cadmium plated (s7) based on the text in the photo and by appearance seems to be a hex head with no shoulder. I myself tend to over specify and so I would say seek an SAE grade 5 which has 3 strikes on the head to avoid it breaking from shaking in the usage intended. 1/4-20, you are testing my memory on whether that is SAE fine or USS coarse in the world I occupied after 1943. Easy to find with round heads and a screw driver type in any hardware store or lumberyard but probably dead soft.


1937sedandelivery    -- 07-19-2019 @ 9:21 AM
  Good to get things correct, you are right. The bolt in my pic is a grade 8 that I had handy at the time. The correct bolt should be per the drawing from the hardware and trimming supplies book. It is the coarse thread.
Thanks for making things right.
Gregg



westgateblvd    -- 07-19-2019 @ 12:17 PM
  How thick is that reinforcement plate?? I may have to make two. I have some 1/8" plate steel I could cut to fit.


1937sedandelivery    -- 07-19-2019 @ 3:41 PM
  It is 24 gauge steel, .0747" thick. I could send you an original piece to make patterns from if you want. I am in Tucson, AZ.
gregg


westgateblvd    -- 07-20-2019 @ 5:19 PM
  Just a picture of what it looks like. I have a lot of sheet metal pieces. I had to make my own firewall.


westgateblvd    -- 07-20-2019 @ 5:44 PM
  Would those bolts be for both mounting to the fender, and the tail lights??


1937sedandelivery    -- 07-20-2019 @ 6:34 PM
  Not sure I understand your question.
The bolt goes through the rear fender and into a threaded area of the tail lamp mount piece. It is used strictly to mount the tail lamp to the fender.
There is also a cup washer on the inside of the fender. The bolt goes through the washer and then a hole in the fender. The threaded area in the mount piece is not very deep so you should take notice of the bolt bottoming out. The washer helps to take up some of the slack.
One final note is to be cognizant of the need to ensure good grounding of the mount to the fender. This provides the ground return path for the bulb circuit.
Good luck.
The attached pic shows the reinforcement piece against a gridded background of graph paper. You may need/want to zoom in to count the squares. The smallest square is .1" x .1".
gregg


westgateblvd    -- 07-21-2019 @ 3:56 AM
  Thanks. So roughly the thickness of a body panel?? If so. I will make a couple up. As far as the grounding goes I learned something while building mine is to have more than one ground strap. I have one to the motor,the frame, the body, the radiator.


1937sedandelivery    -- 07-21-2019 @ 7:49 AM
  I compared the plate thickness to the rear fender thickness (just by touch) and the plate seems a little thicker. It probably isn't real critical unless you are trying to duplicate the original. The plate itself has a slight bit of curvature to it, to conform to the rear fender shape. Also, the center hole, where the wire harness passes through, has a flare to it, with the edge being slightly finished. I suppose this is to prevent chafing of the wire harness, since it just dangles through the holes and can rub. A rubber grommet would work good here, if you don't care about being 100% original/correct. Hmm, wonder why Ford didn't use a grommet...
gregg


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