fastener depth

In general when joining wood, how deep should the fasterners go? To clarify, if I'm joining two 1/2" planks with screws - should I use a 1" screw, a 3/4", 5/8". I'm trying to determine what size screws to order for my next project, and to do that I'll need to figure out how deep the screws should go into the wood. Seems like in the above example 1" screws would be too long, the risk of the point erupting from the wood is too great. But

5/8" is pretty darn short - barely penetrating the second board.

So, it seems like the answer is easy - 3/4". But before I go and ruin a perfectly nice project, I figure I'd better ask just in case.

Reply to
Eigenvector
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You should use the longest screws you can find that don't come out the other side. That being said, no matter what screws you use, 1/2" to 1/2" is going to be a weak fairly attachment no matter what screws you use. I'd certainly use glue in addition to screws and it would help to know where in your project are you joining 1/2" boards? Maybe it's a location that can be joined by other means.

Reply to
Upscale

1/2" to 1/2" is a hypothetical. The actual project itself will involve a whole bunch of different sized boards. What I was interested in hearing, and thanks for the advice - "use the longest screws you can find that don't come out the other side" Glue is definitely going to be used for all the joints - just so I can minimize usage of screws.

For some reason I had it in my head that it was in fact better to use the smallest length screws that still joined the boards.

Reply to
Eigenvector

Just remember, the longer the screws the bigger chance of a split board, pre-drill your holes.

Reply to
FrozenNorth

That's exactly why I thought it was best to use the shortest screws rather than the longest ones. This is where a good drill press comes into play.

Reply to
Eigenvector

As a rule of thumb you want about 1/3 of the screw length going into the piece that is in contact with the screw head.

Reply to
J. Clarke

The rule of thumb is to have 1/3 of the screw in the board to be fastened and 2/3" of the screw into the board being fastened to.

Reply to
Leon

You can't really use a hypothetical question because the thickness of the wood to be joined changes the answer in varying degrees.

Reply to
Upscale

Another rule of thumb is to put your thumb on the back side of the work. If the screw goes into your thumb, it is too long.

Keep in mind that screws not only come in different lengths, but different thicknesses. I use mostly #6 and #8 for typical 3/4" wood but if you are working with 2 x 4's and the like #10 or #12 may be better. Pre drilling a pilot hole helps as does a countersink. You can get bits that do both in one operation.

Buy good screws. Buy from McFeelys, Lee Valley and the like, not Home Depot. I also like the square drive screws too.

Reply to
Edwin Pawlowski

Hmm, didn't know that.

My apologies.

Well in this case I'm installing a 1/2" stiffener board to the backside of a

1" plank surface.. The planks are poplar.
Reply to
Eigenvector

Sometimes the longest possible screw will give the best holding power. You can take a 1" screw and grind off about 1/16" so it won't blow through. I still use a regular screwdriver in cases where I need the greatest possible control, and this sounds like one of them.

Reply to
Phisherman

For that scenario, I'd probably use a #8 1-1/4 or 1-3/8 through the stiffener into the plank. Flat head countersunk if I needed the head to be flush.

Tom Veatch Wichita, KS USA

Reply to
Tom Veatch

See Chapter 7.

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Merrill

Reply to
David Merrill

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