Screws - Coarse vs Fine Threads

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Forum topic by rance posted 06-08-2012 06:30 AM 20174 views 0 times favorited 19 replies Add to Favorites Watch
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4271 posts in 3521 days

06-08-2012 06:30 AM

Topic tags/keywords: screws coarse thread fine thread

I ran across two boxes of 1-1/4” screws the other day. One is coarse and one is fine thread. I realize that coarse are intended more for soft woods and fine are intended for harder woods. I don’t really like stocking both though so I figured that the coarse ones would win out. With hardwoods I pre-drill anyways so I might just have to drill an ever so slightly larger holes for the coarse thread screws. Any reason I might not want to do this? Just a ponderance.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

19 replies so far

View kizerpea's profile


775 posts in 2728 days

#1 posted 06-08-2012 11:54 AM

yeah….if the wood is to hard POP goes the head!


View Jim Jakosh's profile

Jim Jakosh

22524 posts in 3466 days

#2 posted 06-08-2012 12:21 PM

They both have a purpose- especially when using a Kreg fixture where you cannot pre-drill. The fine ones are needed for the hardwoods. When I pre-drill, I use the same drill size for what every wood, the coarser thread cuts the soft wood easier so no bigger hole is needed. The thing is that the OD is the same for both in the same size – say a #8- so the hole should be the same.
My 2 cents worth…...............Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View dhazelton's profile


2837 posts in 2657 days

#3 posted 06-08-2012 01:19 PM

Drywall screws? Fine thread is meant for steel studs.

View rance's profile


4271 posts in 3521 days

#4 posted 06-08-2012 01:43 PM

Yeah, I think they are drywall screws. I just don’t like stocking both. I’m thinking that I can use coarse for both.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View tyskkvinna's profile


1310 posts in 3346 days

#5 posted 06-08-2012 02:53 PM

Honestly I use coarse across the board. If the wood is particularly hard I just go really gentle and sometimes back up and go back down.

-- Lis - Michigan - -

View waho6o9's profile


8638 posts in 2937 days

#6 posted 06-08-2012 03:01 PM

GRKs totally rock, move up a notch and rock on.

View andy_P's profile


415 posts in 3569 days

#7 posted 06-08-2012 03:13 PM

I think what you have to consider is that the threads are taking a good enough bite in the wood surrounding the hole you drill so that it holds. If you are using glue along with the screws, I think this becomes less of a factor. Send me the ones you decide not to use…...LOL.

that’s my cent and a half, rance.

-- Wood is a gift from God/Nature that maintains its beauty forever via the hand of a woodworker.

View fussy's profile


980 posts in 3411 days

#8 posted 06-09-2012 01:04 AM


I wood use whatever I had. Seems that is usually coarse thread. If I’m leery of using coarse in hardwood, I wax the threads with beeswax and go slowly; back out and go again if it seems to bind.


-- Steve in KY. 44 years so far with my lovely bride. Think I'll keep her.

View HamS's profile


1837 posts in 2750 days

#9 posted 06-09-2012 01:09 AM

I was just going to say wax the screws first in hardwood but Fussy beat me to it. I have a cake of beeswak the size of a tuna can on my bench and one in my tool box just for that. I use the wax a lot on hardwood. It usually is not needed in softwood and sheetgoods.

-- Haming it up in the 'bash.

View oluf's profile


260 posts in 3400 days

#10 posted 06-09-2012 01:30 AM

I find beeswax a little hard for using on screws so I buy a wax toilet boal gasket. They are good for about 1000 screws or until you step on it. But than you don’t have to sweep the shop any more. The sawdust will all be on your shoe.

-- Nils, So. Central MI. Wood is honest.Take the effort to understand what it has to tell you before you try to change it.

View rance's profile


4271 posts in 3521 days

#11 posted 06-09-2012 02:25 AM

Good input from all. I think I’ll just use these fine threads where I can until they are all gone. Those are the ones I didn’t buy myself. Any new ones I buy will be coarse(like Lis uses).

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View Roger's profile


21001 posts in 3165 days

#12 posted 06-09-2012 02:42 AM

I use a wax ring from a toilet…. A new one of coarse. I keep a wax ring in an old cookie can, and when I do any screwin, I’ll dip me screw in the wax ring, and go to town

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. [email protected]

View gfadvm's profile


14940 posts in 3051 days

#13 posted 06-09-2012 02:56 AM

Rance, It ruins my whole day when I twist the head off of a screw and it happened too often with those black screws in hardwood so I took the cure. Now they are used only in pine or plywood. Just sayin.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View rockindavan's profile


299 posts in 2997 days

#14 posted 06-09-2012 06:38 AM

Fine threads are nice particularly when using pocket holes (however rare the occasion is), especially when you have to take the joint apart a couple of times. I recently screwed a face frame on to a cabinet and had to take it on and off 2-3 times. Coarse threads have a better chance of stripping out.

View rance's profile


4271 posts in 3521 days

#15 posted 06-09-2012 12:26 PM

Good point Andy. rockin, I’v had just the opposite, the fine seem to strip out more often. Several factors could affect this.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

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