Door sill screws

[71CHEVYSHORTBED402]

I wonder what the factory installed, at least most of the time? I found mine with stainless #2 phillips panhead screws, #10 x 1/2".

But on-line they show stainless #2 phillips countersunk screws, #8 x 3/8". Apparently some of the NOS sill packages included the same. Tried some #8 countersunk screws (two sets, two sources) - sure they work, but it doesn't strike me right, because the heads on countersunk screws should sit flush with a surface. The sills aren't made for them, IMO, because the screw heads aren't flush.

Perhaps just an observation. For what worth, my floor will take #8 even though it had #10. Sometimes I think old #10 are a pinch smaller than new

[cericd]

Here are a couple pics of one of my original door sill screws. When I took them out they had a little rust on them so they have been soaking in Ballistol. They were a dull silver color before I soaked them. I believe they are the original screws because they all match, the sills were original, I am the third owner (father, son, then me) and the interior has never been repainted. I went through some pics I took when I first got the truck back in 2012 and I cropped a section of a pic that shows the finish of the screws back then.

I have a tool that measures machine screws but not sheet metal screws so here are the measurements I was able to get using a metal ruler.

Head Width = 3/8"
Thread Width (before taper) = 3/16" = #10 machine screw according to this chart https://www.boltdepot.com/fastener-i...-Diameter.aspx
Length = hair over 3/8"
Overall Length (top of head to tip of screw) = 1/2"

[truckster]

Originally Posted by 71CHEVYSHORTBED402

I wonder what the factory installed, at least most of the time? I found mine with stainless #2 phillips panhead screws, #10 x 1/2".

But on-line they show stainless #2 phillips countersunk screws, #8 x 3/8". Apparently some of the NOS sill packages included the same. Tried some #8 countersunk screws (two sets, two sources) - sure they work, but it doesn't strike me right, because the heads on countersunk screws should sit flush with a surface. The sills aren't made for them, IMO, because the screw heads aren't flush.

Perhaps just an observation. For what worth, my floor will take #8 even though it had #10. Sometimes I think old #10 are a pinch smaller than new

Technically, those are known as oval head screws. The underside is countersunk and the top is rounded.

[basketcase]

Mine are all pan head screws like in post #2.

[Rust_never_sleeps]

I've seen precious little evidence of the factory installing any stainless fasteners anywhere on this thing ;-)

[pjmoreland]

Originally Posted by Rust_never_sleeps

I've seen precious little evidence of the factory installing any stainless fasteners anywhere on this thing ;-)

Sorry for the off-topic comment. I think the shoulder screws for the park lamp lenses on my '68 are stainless, and I believe they are the originals. They are ever-so-slightly magnetic. Exterior lens screws are probably the only stainless screws to be found. The little sheet metal screws for the rear view mirror mount and the shift indicator might be stainless, too, although they might just be chrome plated.

[71CHEVYSHORTBED402]

Originally Posted by pjmoreland

Sorry for the off-topic comment. I think the shoulder screws for the park lamp lenses on my '68 are stainless, and I believe they are the originals. They are ever-so-slightly magnetic. Exterior lens screws are probably the only stainless screws to be found. The little sheet metal screws for the rear view mirror mount and the shift indicator might be stainless, too, although they might just be chrome plated.

Topic of the rearview mirror screw, I don't know what that is short the material is very light.

Maybe I don't know what stainless is, but if I do models matter. I have a deluxe model, which has basically the same bling as a Cheyenne. Just for kicks and because I have the info. handy, screws for:

Headlight bezels
Rectangular tailgate bumpers
Tail light bezel
Washer nozzles
Cowl panel's top
Transmission pointer & dial
Instrument panel perimeter
Sport mirrors
Vent window at front of window frame
Door panels
Arm rests
Sun visor brackets
Coat hanger
Chrome bumpers
License plate bracket (maybe)
Lenses


Perhaps window regulator, channel and vent window behind the door panel, though they seem to be clear zinc.

Possible the door sills in standard trucks took phosphate screws and Deluxe & above took stainless? Hmm. Regardless, seems we've ruled out countersunk OVAL head screws for a door sill. Funny how that's what the vendors are selling, or most of.

[71CHEVYSHORTBED402]

Interesting, and thanks for the clarification Truckstar, good to know. This is what I pulled off my Chevy. Can't say the factory installed all of them, but some probably were. All pan head, #10

2 1/2" thread length, phosphate
4 1/2" thread length, stainless
2 3/8" thread length, stainless