I just got my new drop in bed liner. When they installed it, they re-used the old torx bolts on the tailgate-these bolts are covered with rust. Does anyone know what size the bolts are and where is the best place to get new ones?

Thanks.

 

They are 1/4" fine thread metric bolts, but you can use any coarse thread 1/4" bolt and it will rethread the hole the metal is thin enough.

 

what????

They are 1/4 INCH fine thread METRIC bolts???? I'm very confused by this... are they metric or not? I'd also like to replace mine as they are rusting, but haven't gotten around to it. Since I put Herculiner in mine, I'd like to buy some black-oxide screws so they match nicely.

If anyone knows what they are really, please let us know!
thanks

 

They are 1/4 inch diameter, meaning you would drill a 1/4 inch hole to put them through with metric threads, actually you would drill a 15/64 (5.95 mm) hole to drop them through.

If you really want to be an **** and get that technical they are 1/4-28 with an NF-UNF pitch and you use drill no. 3 decimal .2130 mm 5.45 this is the thread size and diameters you use to drill and tap a hole to put them in.

Now do like everyone else and just go and get any 1/4 or 15/64 coarse thread bolt of your choice and stick in the hole it will rethread the hole itself since it is only thin sheet metal and be done with it.

Ford has actually switched back and forth between coarse thread 7/32 (5.56 mm) diameter screws and the others I gave the dimensions on above. You don't have to have an exact thread size and pitch as long as the diameteris bigger than the hole diameter it will go in and thread itself.

 

ah, so it appears to simply be a misunderstanding in nomenclature. But, since you want to get technical, we can get technical.

NF ≡ American National Fine. The American National Thread took the US standard sharp V thread and flattened the crests and roots, thereby strengthening the thread.

UNF ≡ Unified Fine. The Unified thread was adopted by the United States, Great Britain, and Canada during World War II. This thread adopted the 60° thread angle of the US (Britain had been using the Whitworth Standard thread with a 55° thread angle) and created a rounded root, with a flattened or rounded crest.

So, calling it a NF/UNF thread is somewhat redundant and technically incorrect. Although most taps are sold as NF/UNF taps.

And now to your "metric thread". A Metric Thread has the same 60° thread angle as the UNF thread. But a Metric thread has a flat root and a flat crest. (remember, the UNF has a rounded root). So it is impossible to have a UNF Metric thread - by definition they are different designs.

Thread size is defined by the nominal diameter. This diameter is defined in either Inches or Millimeters. So theoretically you could call a 1/4" bolt a 6.35mm bolt (since .25*25.4=6.35) but you'd have trouble buying a 6.35mm bolt.

and for tap holes - yes, a 1/4" UNF tap hole size is made with a number 3 drill. This correlates to a diameter of 0.2130 inches. (okey dokey, lets convert that to metric... 5.4102 mm... but its still not a metric thread)

ok, enough ranting. I just get somewhat annoyed when someone mis-speaks and then restates their mistake as fact. Its especially annoying when they try to insult me in the process.

Thanks letting us know its a 1/4" fine thread (or maybe coarse...). Based on the detail of your reply I can trust your knowledge that they are indeed 1/4" bolts. Now I can search for some black oxide screws to replace my rusting ones.

 

I originally was trying to keep it as simple as possible and let them know what to go and buy, that it wasn't necessary to try and find exact matching threads that any 1/4 bolt would work since it would be the most readily available and easiest to find in oxide or stainless.

We didn't let this go far enough before we got technical. That is not the internet forum way. You are supposed to argue about it for 5 pages before even attempting to bring in technical facts or having a 3rd party bring them in. We have broken the rules and I hope that we don't get banned for our indiscretions.

 

Better yet,use a thread guage and do it right the first time.

 

To answer your question, since everyone else seems more interested about arguing over technical details. I would visit my Ford parts guy. Guaranteed to get the proper bolts.

 

Doesn't matter here - mine broke- all of them - drilled 3/16 re-tapped american style - Stainless bolts are a must - Medium Course w/anti seize..

 

Been putting liners in for 20 years never had any of the Ford tailgate screws break. Ford has been using the same ones since around 1994 when they started putting the access panel on the tailgate.

And yes I know I said 20 years (how long we've been in business here) and then I said Ford has only had these screws for 13 years.

 

I 'll get a pic when I go out in the shop tonight - still have the broken ones ..

 

I am not denying that yours did break. I just think it is odd.

 

I bet they rusted in... once the threads rust together its hard to get small screws out without twisting off the heads

Luckily on mine the rust hasn't progressed to the threads yet.


- I'd go with "aftermarket" on the screws... why by the Ford ones when they'll just rust again? Go with SS or a better-coated screw that one rust as soon as it gets a small scratch.

 

+1 on stainless steel (SS) - My exhaust manifold bolts are stainless luckily - some are not in my model year , anyway - they came loose with 13 mm wrench or 5/16 whichever - but I've heard of guys bustin them off in the heads with Fords lower grade bolts -(not stainless) - that really sucks when that happens - Ford updated my 98 in 2000 with stainless and you can't beat em - You most likely won't have a problem again if you choose those..

Beast - I'll get some pics if you want to see, I don't mind - have to remember when I'm out there, That might be a problem lol-... I'll try to.

 

Ya know, that just makes sense, good call.