The Stovebolt Site Forums The Shop Area Paint and Body Shop Fulton visor mounting screws

After a lot of refurbishing, measuring and procrastination I’m going to attempt to mount my Fulton 800 visor today but don’t know what size sheet metal screws to use. I’ve narrowed it down to stainless steel #8 X 3/4” Pan heads or #8 X 3/4” Flat heads. The instructions just say to “attach with the screws included”. Which head should I use? Should I use a finer thread? Also, would a shorter 5/8” length be a better choice?

Thanks

Never installed a Fulton Visor but:
1. If the #8's look beefy enough to hold the weight, then use #8.
2. The length needs to be twice the total thickness of the parts. Too long, and it will interfere or punch thru somewhere.
3. Each size, like # 8, etc, only has one pitch in sheet metal screws. #8 is about 15 TPI.
4. I assume the Fulton has mounting holes and the truck does not. The size and type of holes in the Fulton tell you what size and type of screw to use. Use a size that fits in the hole with a little slop. Use a flat head screw if the Fulton hole is countersunk. Use a pan head of not. The screw you show may not be self tapping and will require a pilot hole in the truck, about 1/8 (check that number before drilling).
5. You may want to set up a test set. Get some pieces of metal with the same thicknesses as the subject. See what pilot works and what screw works to your liking.
6. Do not use power drivers when final tightening unless you know what you are doing.

Good advice Bartamos. Thanks.

I lost one of those in 82 on the 10 freeway in Palm Springs CA. A burst of wind hit me and bounced me off the steering wheel. The guy beside me lost his camper shell. Neither one us looked back to see who's Bentley they were sticking out of.

In this case, do fine threads provide a better grip in an unthreaded hole or are corse threads better at holding?

I just mounted my Fulton Visor. Course threads. I think #8 was perfect. I can confirm later today if needed. Flat Head screws fit perfect.

Are we talking screwing into the drip rail?

1. Many times we don't now the TPI of a sheet metal screw. Like on your package. Some are 15 TPI and some may be 18 TPI. That is a difference of only .011 per thread if you want to relate it to cab sheet metal thickness.
2. The smaller the screw the finer the TPI.
3. In general, you get only one TPI for a certain type of sheet metal screw.
4. We can't equate TPI in Sheet metal to regular machine screws.
5. When we buy wood screws, many of use "drywall screws". That's what I use. They have coarse and fine. Course is for drywall to wood studs and fine is for drywall to metal studs. I use them for wood to wood, with one piece having a clearance hole and the other no hole. Many of the threads are engaged into the wood.
6. With a pointed sheet metal (self tapping) screw like you show, you need a pilot hole. The clamping, in thin metal, is by one thread, approx. It cuts only one partial "thread" into thin sheet metal, with proper pilot hole. But being spiral, the thread clamps by being a one thread ramp wedge. That is why several sizes work on the same thin sheet metal. It is why the pitch is not the same kind of factor as machine screws and wood screw deep engagement. Hard to equate to other type screws.
7. With a self drilling sheet metal screw you don't need a hole.
8. I realize this is way too much blogging about nothing. It's a perspective answer to your questions. Sheet metal screws are different. Thought of for light weight or low tensile/pull out applications. It would be much better to use machine screws with nuts, but I know that is not possible. I don't think a visor is low weight and I think a headwind will apply great pullout force. That must be wrong because I don't know of any bad stories.

McMaster Carr has metal screws in many TPI's and varieties. You will have them faster than Amazon and you can buy just one.

McMaster Carr has metal screws in many TPI's and varieties. You will have them faster than Amazon and you can buy just one. They have exact drawings on all their fasteners.

The Fulton installation instructions tell you to drill four .110 holes (no. 35 drill). I’m not familiar with a “no. 35” drill bit. Is that what size I’d ask for at the store or is there a corresponding size like 1/8” I should ask for?

Also, regarding my original post asking what size screws to use, I finally found in the instructions where they say to use eight 6 x 3/8” self-tapping screws. I’ll have to buy some. Are self-tapping screws that much different than regular sheet metal screws except for the “drilling” tip on a self-tapping screw?

What say you Bartamos???

Thanks

Drill bit sizes.

I'm not sure if your local hardware store will have the numbered sizes. McMaster or Grainger do. If you can't find a #35, then go smaller with a 7/64".

Also, I have found that self tapping screws tend to waller out the hole some and will come loose sooner rather than later. A properly drilled hole and a sheet metal screw will stay tighter much longer. More work but lasts longer.

Thanks Mark for both the drill bit size charts and the advice about self-tapping vs. sheet metal screws. Much appreciated!

One last related question...... nowhere in the original Fulton installation instructions can I find the dimensions for the 4 very small aluminum screws that attach the wings to the round angle brackets. (Fulton refers to them as connecting yokes) I’d like to buy replacements and don’t know the size. If anyone knows I’d appreciate it if you’d share that info with me.

Thanks a lot.

#8 x 3/4 Stainless

My Fulton visor has been on the '49 truck for 20 years and over 100k miles attached with ss screws. When I re-mount the visor on a new cab I will use Riv-Nuts, vastly superior to screws for this application, IMHO.