What length screw to use?
Joe J
drywall. Are 3" screws long enough, I have a bunch leftover from a
different project? The 2 x 4s will be holding 5/8 plywood for shelves. Or,
should I just bite the bullet and go with 3 1/2?
Thanks
jamesgangnc
It's not the length, it's how you use them :-)
dpb
Ditch the drywall screws for the purpose entirely.
--
jamesgangnc
He didn't say he had drywall screws. He's saying that he has to go
through a 2x4 and drywall to reach the stud. With three inch screws
he's going to get about an inch into the stud. With 3 1/2 it will be
a bit more. If I had the 3" laying around I might just use a few more
of them and consider it to be good enough.
Gordon Shumway
When choosing length, try to have about 1/3 of the screw in the piece
being fastened and the remaining 2/3 of the screw threaded into the
piece being fastened to. As the thickness of the lumber increases
though, this ratio can be reduced to 1/2 if absolutely necessary.
That's why only 2/3 of the shank is typically threaded on our 1" and
longer wood screws.
In your example the preferred screw length would be ~4-1/2" to 5"
Gordon Shumway
A Liberal is a person who will give away everything he doesn't own.
jamesgangnc
Since he suggested using a 3" I believe he is going through the narrow
dimension of a 2x4. Which is around 1 1/2" plus 1/2" of wall board.
Joe J
"jamesgangnc" <james...@gmail.com> wrote in message
news:45362997-c731-4380...@d37g2000yqm.googlegroups.com...
Correct, 1 5/8 to be exact, plus the drywall at 1/2". So, 2 1/8" total. If
I drive them through the 2x4 hard, they'll countersink about an 1/8, so I
would have about 1" into the stud.
Wayne Whitney
> I'm attaching 2 x 4s to the studs in a finished garage. Finished
> with 1/2" drywall. Are 3" screws long enough, I have a bunch
> leftover from a different project?
Here's what the National Design Specifications for Wood has to say on
the matter:
For laterally loaded wood screws, the minimum embedment is 4 times the
shank diameter, and to develop the full lateral strength, you need an
embedment of 7 times the shank diameter. You also need to drill a
pilot hole at around 90% of the root diameter.
Withdrawal capacity is linear in embedment, so the more the merrier.
This becomes an issue if you are applying an eccentric lateral load,
e.g. your 2x4s are going to be support shelves, where the weight is
some distance from the wall. Then the top set of screws is loaded in
tension.
As an example a #10 screw has a shank diameter of 0.190" and a root
diameter of 0.130". So to develop the full lateral capacity, you'd
want an embedment of 1.33" and a 7/64" or 1/8" pilot hole. With a 3"
screw, you could achieve the necessary embedment in your situation by
counterboring the 2x4s by 1/2".
Cheers, Wayne
John
shanks in your 2x4's (shanks are holes that are wide enough so that
your screw can slide through without the thread catching -- you don't
want the thread catching both the 2x4 and the wall), so if you use a
counter-sync/shank combo, you should be be able to embed the 3" screws
a 1/2" into the wood easily enough. If you don't have one of those,
you might want to consider buying some 3 1/2 - 4" screws that have no
thread the top 1 1/2". That way you won't have to do any shanking,
and the shelves go up faster.
John
Joe J
"John" <john...@broadcom.com> wrote in message
news:706a5ee2-3e3d-4401...@s1g2000prf.googlegroups.com...
Why wouldn't I want the screw to catch both the 2x4 and the wall stud?
Seems to me that would make a nice tight fit.
--
Joe J.
keith
> "John" <john.u...@broadcom.com> wrote in message
When you snug the 2x up to the wall there is no gap. If the threads
are sunk into both boards, one or the other has to strip out to close
the gap. You don't want that force stripping the threads out of the
hole in wall stud.
HeyBub
> On Tue, 8 Jun 2010 07:51:30 -0500, "Joe J" <joe...@prodigy.net> wrote:
>
>> I'm attaching 2 x 4s to the studs in a finished garage. Finished
>> with 1/2" drywall. Are 3" screws long enough, I have a bunch
>> leftover from a different project? The 2 x 4s will be holding 5/8
>> plywood for shelves. Or, should I just bite the bullet and go with
>> 3 1/2?
>>
>> Thanks
>
> When choosing length, try to have about 1/3 of the screw in the piece
> being fastened and the remaining 2/3 of the screw threaded into the
> piece being fastened to. As the thickness of the lumber increases
> though, this ratio can be reduced to 1/2 if absolutely necessary.
>
> That's why only 2/3 of the shank is typically threaded on our 1" and
> longer wood screws.
No, the shank of a wood screw is smooth so that the screw will slip through
the material being held and snug it up to the base material.
>
> In your example the preferred screw length would be ~4-1/2" to 5"
>
Adequate screw length depends on the load. If screwing to a wall and the
load is straight down, you can get away with a MUCH shorter screw than if
the load is horizontal, or nearly so, to the wall. It's the difference
between hanging a picture and an L-bracket for a shelf. A thumb-tack may
hold a 30# picture but not a shelf bracket.
Steve Barker
drywall screws come 3 or 3 1/2 inches long anyway.
--
Steve Barker
remove the "not" from my address to email
Steve Barker
Some of these later replies are hyfuckinglarrious!! you HAD to ask,
didn't ya?
keith
> On 6/8/2010 8:18 AM, dpb wrote:> Joe J wrote:
> >> I'm attaching 2 x 4s to the studs in a finished garage. Finished with
> >> 1/2" drywall. Are 3" screws long enough, I have a bunch leftover from
> >> a different project? The 2 x 4s will be holding 5/8 plywood for
> >> shelves. Or, should I just bite the bullet and go with 3 1/2?
>
> > Ditch the drywall screws for the purpose entirely.
>
> > --
>
> he never said anything about 'drywall' screws. And i don't think
> drywall screws come 3 or 3 1/2 inches long anyway.
Of course you don't think (they indeed do).
Steve Barker
Nice. Insult me, when it was YOU that made the mistake.
John
Sometimes you get worse, and you can't strip out the threads from
either the wall, or the board, and that's worse.
Lets say you were putting a screw through your 2x4 to the wall, and
that the screw thread caught tightly on both. Also, lets say when you
were doing this, there was a 1mm gap between your board and the wall,
because you weren't holding it just right. You screw the screw in as
far as it goes, but there's still 1mm gap. Picture that you manage to
do one last turn of the screw, the screw moves 1mm further into the
wall -- well, it also moved 1mm further into the board, but because of
this, the board does not get tighter to the wall).
If, on the other hand for some reason the screw thread does not catch
on the board, because you either drilled a shank hole, or because the
screw has no thread for the depth of the board, then turning that
screw an extra turn pulls the board 1mm closer into the wall. This
creates tension and friction between the wall and the board, and that
is where you get your real strength. If you're having trouble
picturing it, fasten two boards to the wall -- one with a shank, and
one without, and hit the top of both boards with a sledge hammer. The
screws will likely break in the one without the shank holes, but
you'll likely just dent the board/wall in the other.
John
k...@att.bizzzzzzzzzzzz
k...@att.bizzzzzzzzzzzz
wrote:
>On 6/8/2010 7:51 AM, Joe J wrote:
>> I'm attaching 2 x 4s to the studs in a finished garage. Finished with
>> 1/2" drywall. Are 3" screws long enough, I have a bunch leftover from a
>> different project? The 2 x 4s will be holding 5/8 plywood for shelves.
>> Or, should I just bite the bullet and go with 3 1/2?
>>
>> Thanks
>
>Some of these later replies are hyfuckinglarrious!!
It's only funny because you're too stupid to understand simple mechanics.
>you HAD to ask, didn't ya?
Because you can't answer, doesn't mean the question is stupid.
k...@att.bizzzzzzzzzzzz
Yes, in addition, the screw is now in shear rather then bending in the 1mm
between the board and the wall. Sheetrock kinda messes this up, but...
David Nebenzahl
Right concept, but the correct term is "clearance hole" for the screw,
or counterboring it into the piece being held.
--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.
- Comment from an article on Antiwar.com (http://antiwar.com)
Gordon Shumway
wrote:
>> When choosing length, try to have about 1/3 of the screw in the piece
>> being fastened and the remaining 2/3 of the screw threaded into the
>> piece being fastened to. As the thickness of the lumber increases
>> though, this ratio can be reduced to 1/2 if absolutely necessary.
>>
>> That's why only 2/3 of the shank is typically threaded on our 1" and
>> longer wood screws.
>
>No, the shank of a wood screw is smooth so that the screw will slip through
>the material being held and snug it up to the base material.
Yes, 1/3 of the shank is smooth and the other 2/3 of the shank is
threaded.
>
>>
>> In your example the preferred screw length would be ~4-1/2" to 5"
>>
>
>Adequate screw length depends on the load. If screwing to a wall and the
>load is straight down, you can get away with a MUCH shorter screw than if
>the load is horizontal, or nearly so, to the wall. It's the difference
>between hanging a picture and an L-bracket for a shelf. A thumb-tack may
>hold a 30# picture but not a shelf bracket.
Yes again, but if he NEEDS to use a 2x4 then he NEEDS screws with
similar holding power.
Joe
>snip>
> > Since he suggested using a 3" I believe he is going through the narrow
> > dimension of a 2x4. Which is around 1 1/2" plus 1/2" of wall board.
>
> Correct, 1 5/8 to be exact,
>snip<
1 1/2" has been the standard stud thickness now for many decades.
Google 'lumber thickness standards for more info.
Joe
Ed Pawlowski
"Joe J" <joe...@prodigy.net> wrote in message
news:hulecf$ok2$1...@news.eternal-september.org...
I'd use them. I'd also put a dab of construction adhesive in four or five
spots too on the ones hanging the shelves. .
aemeijers
I have not been paying attention- these are horizontal 2x4s, right? To
act as a ledger for the shelves? Or vertical 2x4s to hold brackets? On a
horizontal 2x4, you may wanna go with a wider board, to reduce the lever
action that will dig into the drywall. Back in the stone age, for
closets and utility rooms and such, I always had good luck with a pretty
1x8 band screwed into the studs, and metal brackets screwed into that
wherever needed. Held a 12" shelf, supported by the brackets and the top
edge of the 1x8, heavily loaded, with no problem.
--
aem sends....
k...@att.bizzzzzzzzzzzz
For closets, just run boards around the three sides and put a shelf on top. I
despise those metal brackets.
trophy...@usolympics.com
<k...@att.bizzzzzzzzzzzz> wrote:
>>>>
>>>> he never said anything about 'drywall' screws. And i don't think
>>>> drywall screws come 3 or 3 1/2 inches long anyway.
>>>
>>> Of course you don't think (they indeed do).
>>>
>>
>>Nice. Insult me, when it was YOU that made the mistake.
>
>Wrong again, dope.
ATTENTION EVERYONE. Steve Barker is an idiot. PLEASE INSULT HIM.
Everyone who reads this is required to insult this guy. Give him
shit! Show him what an idiot he is.
Steve B
"Joe J" <joe...@prodigy.net> wrote in message
news:hulecf$ok2$1...@news.eternal-september.org...
> I'm attaching 2 x 4s to the studs in a finished garage. Finished with
> 1/2" drywall. Are 3" screws long enough, I have a bunch leftover from a
> different project? The 2 x 4s will be holding 5/8 plywood for shelves.
> Or, should I just bite the bullet and go with 3 1/2?
>
> Thanks
Let's do the math. 2 x 4's are actually 1 1/2" thick some 1 5/8". Drywall
1/2", less an eighth or so for recess. That gives you about an inch of
penetration into the stud that will hold it all. I'd use them.
Steve
visit my blog at http://cabgbypasssurgery.com
A fool shows his annoyance at once, but a prudent man overlooks an insult.
JamieC
Don't you think that that is a little bit immature? I would expect it from a
child.
--
for full context, visit https://www.homeownershub.com/maintenance/what-length-screw-to-use-446178-.htm
DerbyDad03
> replying to trophywinner, JamieC wrote:
> Don't you think that that is a little bit immature? I would expect it from a
> child.
>
back then.
Thanks for playing!