Door threshold hold down screws - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**MikeB** · Today, 02:22 PM

I'm sure most of you have had the problem where the hold down screws hog out the holes in the floor and no longer grip the sheet metal screws. So you end up using larger screws, but eventually they no longer grip the holes.

I'm considering drilling out the holes and installing rivet nuts for 10-24 machine screws. Have any of you done this? Any cons you can think of?

OK, after doing some research, my best bet looks like 10-24 machine screws with speed nuts like these:
https://www.homedepot.com/p/Everbilt...0118/204274180

**dagnabbitt** · Today, 04:31 PM

I always thought sheet metal screws (non stainless ones, too) for that was an odd choice. I think rivnuts would be a great idea.

LS short box · Today, 05:09 PM

Couple thoughts.
First weld up the existing holes just a bit so the stock screws can get a bite.
Or take a strip of 18? gauge sheet metal and tack weld it to the jam and drill new holes?

**pjmoreland** · Today, 05:35 PM

I've had success repairing the holes by holding a heavy chunk of steel against the bottom surface of the floor followed by striking the hole from the top with a hammer a few times. This will flatten the metal out, and it will collapse the hole inward.

**chewychevy67** · Today, 05:41 PM

So instead of using the original sheet metal type screws for my sill plates I decided to use t nuts like this. They sit in the hole you drilled and give you extra thread for a real threaded bolt. Nut gets welded/glued on the flange to the body underneath and it will tighten better without stripping and it will still look like a truss head from the top. I used shorter bolts than what was in these photos and they are phillips head for a factory look.

**MikeB** · Today, 06:33 PM

Thanks for the advice! I ended up ordering some #10-24 stainless truss head screws, serrated nuts, and washers from Bolt Depot. Can't believe how much I was overthinking things!

If you guys have never used Bolt Depot, I strongly recommended them. They have all grades of nuts and bolts at very low prices, with dimensions and drawings on each one of them! You can buy small quantities and they don't gouge you on shipping. Every stock number comes in its own labeled zip-lock bag. https://boltdepot.com/Catalog

Today, 04:31 PM	#2
dagnabbitt Senior Member Join Date: Dec 2014 Location: Edmonton Alberta Posts: 1,501	Re: Door threshold hold down screws I always thought sheet metal screws (non stainless ones, too) for that was an odd choice. I think rivnuts would be a great idea. __________________ DAVE Edmonton, Alberta 1959 Apache 1967 K20 1968 C20 1970 C10 1972 GMC 2500 1981 C10

Today, 05:09 PM	#3
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 2,190	Re: Door threshold hold down screws Couple thoughts. First weld up the existing holes just a bit so the stock screws can get a bite. Or take a strip of 18? gauge sheet metal and tack weld it to the jam and drill new holes?

Today, 05:35 PM	#4
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 6,151	Re: Door threshold hold down screws I've had success repairing the holes by holding a heavy chunk of steel against the bottom surface of the floor followed by striking the hole from the top with a hammer a few times. This will flatten the metal out, and it will collapse the hole inward.

Today, 05:41 PM	#5
chewychevy67 Senior Member Join Date: Jan 2010 Location: Here Posts: 5,585	Re: Door threshold hold down screws So instead of using the original sheet metal type screws for my sill plates I decided to use t nuts like this. They sit in the hole you drilled and give you extra thread for a real threaded bolt. Nut gets welded/glued on the flange to the body underneath and it will tighten better without stripping and it will still look like a truss head from the top. I used shorter bolts than what was in these photos and they are phillips head for a factory look. Attached Images

Today, 06:33 PM	#6
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,649	Re: Door threshold hold down screws Thanks for the advice! I ended up ordering some #10-24 stainless truss head screws, serrated nuts, and washers from Bolt Depot. Can't believe how much I was overthinking things! If you guys have never used Bolt Depot, I strongly recommended them. They have all grades of nuts and bolts at very low prices, with dimensions and drawings on each one of them! You can buy small quantities and they don't gouge you on shipping. Every stock number comes in its own labeled zip-lock bag. https://boltdepot.com/Catalog __________________ Mike 1969 C10 LWB -- owned for 36 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

Today, 02:22 PM	#1
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,649	Door threshold hold down screws I'm sure most of you have had the problem where the hold down screws hog out the holes in the floor and no longer grip the sheet metal screws. So you end up using larger screws, but eventually they no longer grip the holes. I'm considering drilling out the holes and installing rivet nuts for 10-24 machine screws. Have any of you done this? Any cons you can think of? OK, after doing some research, my best bet looks like 10-24 machine screws with speed nuts like these: https://www.homedepot.com/p/Everbilt...0118/204274180 __________________ Mike 1969 C10 LWB -- owned for 36 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! Last edited by MikeB; Today at 02:45 PM.

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