Pilot hole...
#1
04-23-13, 07:04 PM
Pilot hole...
Hi, I want to screw an antenna mount in the attic. The mount comes with hex-head screws that have a "root" of slightly less than 3/16 of an inch. Including the thread, the size is 1/4 of an inch. The head fits in a 3/8 hex socket.
What is the size of the pilot hole I must drill in the wood to properly torque the screw in the wood?
What is the size of the pilot hole I must drill in the wood to properly torque the screw in the wood?
Last edited by alesan; 04-23-13 at 07:42 PM.
#4
04-23-13, 08:04 PM
So according to this table, a screw that has a thread diameter of about 1/4" is a #14:
Bolt Depot - Wood Screw Diameter and Number Table
And according to this other table, a tapered #14 screw on softwood would need a 15/64" hole, that is more than 3/8"... I am thoroughly confused!
Bolt Depot - Pilot Hole Sizes for Wood Screws
Bolt Depot - Wood Screw Diameter and Number Table
And according to this other table, a tapered #14 screw on softwood would need a 15/64" hole, that is more than 3/8"... I am thoroughly confused!
Bolt Depot - Pilot Hole Sizes for Wood Screws
#5
04-23-13, 08:21 PM
Group Moderator
Right.... a 1/4" is roughly a # 14
For a # 10 screw I would use a 1/8" bit
For a # 12 screw I would use a 3/32" bit
For a # 14 screw I would use a 3/32" bit
Usually my 3/32" is broken and I use 1/8" for everything.
I buy 1/8" bits by the box of 100.
Technically putting that screw into the center of a 2x4 shouldn't split it without pre-drilling.
So if you use either of the two sizes we mentioned you'll be in good shape. If you are really concerned about binding......use a little soap or candle wax.
For a # 10 screw I would use a 1/8" bit
For a # 12 screw I would use a 3/32" bit
For a # 14 screw I would use a 3/32" bit
Usually my 3/32" is broken and I use 1/8" for everything.
I buy 1/8" bits by the box of 100.
Technically putting that screw into the center of a 2x4 shouldn't split it without pre-drilling.
So if you use either of the two sizes we mentioned you'll be in good shape. If you are really concerned about binding......use a little soap or candle wax.
#6
04-23-13, 08:25 PM
Oh wait, these are the screws I have:
[ATTACH=CONFIG]11870[/ATTACH]
And it seems they are NOT tapered... so the table I linked suggests a 5/32" like you said, chandler. Thank you and sorry to have doubted your expertize!
[ATTACH=CONFIG]11870[/ATTACH]
And it seems they are NOT tapered... so the table I linked suggests a 5/32" like you said, chandler. Thank you and sorry to have doubted your expertize!
.
