Screw question

[Wooden Skye]

I need to sandwich a very thin piece of sheet metal (no clue to the gauge) between 2 pieces of wood, what is the best screw for this?  Would normal wood screws work, or are self tapping screws better?

Thanks.

 

[Brice Burrell]

If you predrill any screw will work.  If not predrilling pretty much any screw with a cutter tip will go through thin sheet metal.

 

[Wooden Skye]

Thanks Brice.  For this I am not planning on predrilling.

 

[rrmccabe]

Well knowing the gauge is important since you don't want to predrill.

 

[Wooden Skye]

I could probably break in half by folding back and forth several times, or easily cut with tin snips.  I didn't buy the metal.

 

[polarsea1]

I'm thinking Spax.

 

[Brice Burrell]

I'm thinking Spax.

I've used Spax screws but prefer GRK.  Our local Home Depots carries both.

 

[jmbfestool]

Any wood screw with a cutter tip will fly through that thin stuff.

But!!!!

You say your going to sandwich the metal sheet.....to me that sounds like its going between two pieces of timber.  You also say your not going to pre-drill..... Now thing is when the wood screw hits the metal it will stop for a little untill it has cut through then it will carry on going in.  Now what will happen your first layer of timber will raise up the screw away from the metal sheeting.  To avoid this you need to do a clearance hole on the top layer first.

 

[Alan m]

jmb is right.
the top layer will lift and then all the swarf from drilling the metal will go inbetween . then the two layers wont close up again.
i would drill the top layer and the metal first and then screw it down to the second layer

 

[Deansocial]

It's the same for screwing any 2 things together. You need clearance in first bit to stop screw jacking

 

[jmbfestool]

It's the same for screwing any 2 things together. You need clearance in first bit to stop screw jacking

Not really dude.   If you held two pieces of timber together they stay in ''floating'' position so if they where touching they would stay touching  if you held them 10mm apart they would stay 10 mm apart cus your driving the screw in at the same rate in both materials of the same.

Even if their was a slight difference your body weight would easily fight against it   but if you hit metal your body weight would NOT keep it down it would actually lift you up or damage the screw or it would spin inside the wood creating a kinda clearance hole.  All would depend on the wood and screw size etc.

JMB

 

[Deansocial]

Quite often screwing 2 things together you hit the second piece and it pushes away, yo back the screw of then got again. You do it with your structural screws, ive seen you do it!

 

[Alan m]

i always try and buy screws with a non threaded section. all threaded screws are a pain to use because they act on both pieces the same as the screw turns. the ones with the round part allow the pieces to be pulled together

 

[Deansocial]

i always try and buy screws with a non threaded section. all threaded screws are a pain to use because they act on both pieces the same as the screw turns. the ones with the round part allow the pieces to be pulled together

I agree with that Alan. Much better to have the smooth section at the top.

 

[Davej]

Another way round it it is just clamp the pieces first . Even if you dont  you may get a bit of jacking but if you keep going the pieces usually pull back together , decent screws are a must though .

 

[rrmccabe]

It's the same for screwing any 2 things together. You need clearance in first bit to stop screw jacking

Not really dude.   If you held two pieces of timber together they stay in ''floating'' position so if they where touching they would stay touching  if you held them 10mm apart they would stay 10 mm apart cus your driving the screw in at the same rate in both materials of the same.

Even if their was a slight difference your body weight would easily fight against it   but if you hit metal your body weight would NOT keep it down it would actually lift you up or damage the screw or it would spin inside the wood creating a kinda clearance hole.  All would depend on the wood and screw size etc.

JMB

Not sure I agree with that.  The screw is engaged in the first piece and driving at a given rate as you mention. But there is a slight delay as the screw starts into the second piece before it gets into decent thread. Because of this it will lift the board unless you are using a lot of pressure or have it clamped.

 

[jmbfestool]

It's the same for screwing any 2 things together. You need clearance in first bit to stop screw jacking

Not really dude.   If you held two pieces of timber together they stay in ''floating'' position so if they where touching they would stay touching  if you held them 10mm apart they would stay 10 mm apart cus your driving the screw in at the same rate in both materials of the same.

Even if their was a slight difference your body weight would easily fight against it   but if you hit metal your body weight would NOT keep it down it would actually lift you up or damage the screw or it would spin inside the wood creating a kinda clearance hole.  All would depend on the wood and screw size etc.

JMB

Not sure I agree with that.  The screw is engaged in the first piece and driving at a given rate as you mention. But there is a slight delay as the screw starts into the second piece before it gets into decent thread. Because of this it will lift the board unless you are using a lot of pressure or have it clamped.

If you read all if it I do say if there is a slight difference your own body weight would stop it lifting but if you hit metal it would lift you up.

 

[greg mann]

The only way to get full pressure is to drill the first board for thread clearance and have the thread engagement in the last board. You can have two boards snug to each other with thread engagement in both but the pressure between them will be neutral.

 

[jacko9]

Contact McFeely's and ask what screw they would recommend.

Jack

 

[aptpupil]

Not enough information to answer. What are the thicknesses and types of wood? Thickness/type of metal? If we're talking 24 gauge SS then it might not be as easy to pierce as you think. If you're talking about a dense wood then predrilling would be needed anyway. If we're talking about douglas fir and basic sheet metal then I think clamping and pressing down hard with a sharp tipped screw would be fine at avoiding the screw jacking others rightfully brought up. Beyond that it's tough to say.