Screw thickness in comparison to the wood

[23Sojourney45]

What is the consensus on here for screw thickness? In this forum, I've read about the different types of screws, fasteners, nails, etc...but haven't really come across screw thickness or is that not even a thing? For example, someone mentioned using a #8 screw and was adamant about finding deals.
Why not use a #6? (9/64 according to the american screw website) or a #5 or #10?
Does it depend on the thickness of the wood?
Do you ALWAYS need a pilot hole?

Thinking out loud, if I have a piece of wood and just a random screw (obviously logic is involved because I'm not using a 1/4 inch thick screw to screw into a 1/4 inch thick wood), I could just screw it into the wood no problem, BUT if I don't want the wood to crack then I would drill a pilot hole using a smaller drill bit than the screw. Now, to be a little more specific, if I have a 1x2 inch board (actual 3/4 inch x 1.5 inch) and I want to screw a wall to the 3/4 inch side, what size screw should I use? a #8 and pre-drill? or go smaller? I'm asking because I'm building my floor and floor flame and will screw my side walls to the 1x2 frame, specifically the 3/4 side. My side walls will be about 5/8 to 3/4 thick. I didn't want to go crazy with putting a crazy amount of screws because I'm paranoid of it not holding. Obviously, will use glue, PL premium/Liquid Nails/Gorilla...along with the screws.

I'm also asking because I'm going to the store in the next couple of days and buying box screws which I will be using for the rest of the build as well...spars, cabinets etc...I didn't want to buy a box of "wrong" screws lol. Thanks in advance.

[Tom&Shelly]

I seldom worry about screw thickness, since I'm thinking of screw length, and the thickness of what is commonly available usually goes along with that.

For the teardrop, practically all of the screws were stainless steel. For most other work, I like deck screws. For temporary things and some shop jigs I use drywall screws, or whatever I happen to have.

I almost always drill pilot holes. About the diameter of the shank of the screw for hardwood, maybe a bit less for pine. The hole in the piece being screwed into should, properly, be drilled with a larger hole, about the size of the thread diameter, so the screw clamps the wood together. I don't always do that, especially if it's inconvenient, or if I'm using flat heads, as the screw head often takes much of the depth of the piece being screwed into.

I usually use a lot, and seldom have things come apart.

About exhausts my knowledge...

Tom

[23Sojourney45]

I seldom worry about screw thickness, since I'm thinking of screw length, and the thickness of what is commonly available usually goes along with that.

For the teardrop, practically all of the screws were stainless steel. For most other work, I like deck screws. For temporary things and some shop jigs I use drywall screws, or whatever I happen to have.

I almost always drill pilot holes. About the diameter of the shank of the screw for hardwood, maybe a bit less for pine. The hole in the piece being screwed into should, properly, be drilled with a larger hole, about the size of the thread diameter, so the screw clamps the wood together. I don't always do that, especially if it's inconvenient, or if I'm using flat heads, as the screw head often takes much of the depth of the piece being screwed into.

I usually use a lot, and seldom have things come apart.

About exhausts my knowledge...

Tom

Thanks Tom, it's good to know that the thickness of the screw shouldn't matter in contrast to the length. I'm not going to be needing anything too long. I don't mind drilling pilot holes either, especially if it will help not have any cracks. Stainless steel is the preferred method? most likely because it may come into contact with the outside correct? for the ones inside, never to be seen by the light of day, regular screws I'm assuming.

[Pmullen503]

For what you are describing, #8 is fine. I would recommend getting a combination pilot hole/countersink bit of the correct size.

Something like this: https://www.amazon.com/DEWALT-DW2700-Drill-Drive-Complete/dp/B0000DD6LX/ref=zg_bs_g_552396_sccl_12/144-6111966-8896924?th=1 that has the bit and countersink together.

I prefer stainless if the heads are going to show.

[23Sojourney45]

For what you are describing, #8 is fine. I would recommend getting a combination pilot hole/countersink bit of the correct size.

Something like this: https://www.amazon.com/DEWALT-DW2700-Drill-Drive-Complete/dp/B0000DD6LX/ref=zg_bs_g_552396_sccl_12/144-6111966-8896924?th=1 that has the bit and countersink together.

I prefer stainless if the heads are going to show.

Thanks Pmullen, that's a nice gadget to have in the toolbox, will definitely have to check it out. I do have some #8's left but I'm going to need more in this case since it should be fine. I'm probably over thinking this whole thing which I'm sure never happens when it comes to TD building lol...its a right of passage I'm sure.

[philpom]

I used a combination of #8 and #10 screws and pre-drilled everything plus a countersink. SS screws where visible. Mentioned above was length, I think that is more important. Even the least bit of through on some of the screws would be disastrous IMO. Can you imagine mounting a shelf and punching through your siding? I used a combination of 3", 2.5", 1.5", 5/8", and even some 1/2" if memory serves.

Good luck!

[Tom&Shelly]

Stainless steel is the preferred method? most likely because it may come into contact with the outside correct? for the ones inside, never to be seen by the light of day, regular screws I'm assuming.

We used stainless everywhere. We've camped on coasts and in humid conditions. The hardware doesn't need to be immersed in water to corrode.

Tom