Sheet rock screws: fine vs coarse thread?

Awl --
Purpose? Applications?
The minor diameter of the fine thread (under 2") appears to be about .115 (mebbe less, due to inadequate penetration of caliper edge), and .090 on the
coarse. Ergo, more "grab" with the coarse.
I'm guessing the following:
Coarse thread is for sheet rock on metal studs -- more grab on studs. Altho framing screws, which afaik are only for metal stud to metal stud, also come in coarse and fine thread, so this may muddy this particular logic. Mebbe for different gauges of metal studs? I've seen some much heavier than others.
Coarse thread for particle board et al.
Fine thread for hardwood.
Opinions?
fyi, there exists a 3/4" and 1 1/8 SR xcrew, very hard to find. The 3/4 is VERY handy, when screwing from the back side of a good face, and the 1 1/8 occasionally comes in handy. A good hardware store, proly one that sells SR screws by the pound, can order a 25# box. If he hesitates, tell him that the 3/4" will FLY out of the store when people grok their utility.
--
EA



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The Gougeon Brothers of sailboat fame did tests of coarse- versus fine-thread screws in wood back in the '60s. Coarse-thread won. Sheet metal screws beat wood screws in wood every time. That was before sheet rock screws.
--
Ed Huntress



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ed Huntress wrote:

www.mcFeelys.com
About any screw you might want, and square drive is the ONLY option as far as I'm concerned!
Stuart
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

re: "square drive is the ONLY option as far as I'm concerned!"
Unless you think you might find yourself with the need to disassemble what you've put together and there's a danger of no (or not enough) square drive bits being available.
I'm often involved in set-up and tear downs for events where lots of dry wall screws are used. You can *always* find a screw gun, usually with a # 2 phillips bit already installed, within arm's reach. Try locating a square drive bit - and of the right size - when something needs to fixed/adjusted with moment's notice.
When it comes to volunteer events like these, you want to go with the most common fasteners so that anyone (and everyone) can pitch in. # 2 phillips screws are still the most common and I don't see that changing any time soon - even if square drives are better.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
DerbyDad03 wrote:

The problem you mention is easily solved by having a few packages of #2 square drive bits. I work in Theatre, we put up and tear down all the time, and there is NO comparison, esp if the head has some paint in it. Also, if a square drive bit becomes slightly worn, it can usually be re-conditioned enough to finish the show, just by lightly tapping it on a running belt sander, you can't do that with a phillips. I have known places that used one type of fastener for all permanent inventory, and the other fastener for stuff that is meant to last just for the show. then if only one driver type is on the deck at strike, the good stuff gets saved.
BTW, screws are a single use item. The biggest source of frustration is trying to save and re-use screws.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

re:
1 - "The problem you mention is easily solved by having a few packages of #2 square drive bits..."
2 - "BTW, screws are a single use item"
1 - Not really and 2 - not in all cases.
At the events that I'm talking about, the equipment that is used by the competitors require - by rule - upwards of 40 # 2 Philips head dry wall screws. Therefore, that is the bit that everyone has in their screw guns. Square drive screws are not an an option in the competitor's equipment. The screws for the competitor's equipment don't get stressed or torqued very tight, so they are used over and over and over again with no damage. The only time they get replaced is when they get lost or rusty.
Now, as for the set up and tear down portions of the events, the organizers opt for # 2 Philips head screws of various types and sizes so that we're not constantly looking for and changing bits depending on whether we're working on the competitor's equipment or the event infrastructure. I know that these screws are single use items, but there are many "helpers" who don't.
At one point I snuck in a bunch of those Deckmate screws that took the square tip Phillips bits. I used them for the heavier construction parts of the set up. Talk about Phillips bit chatter when other people tried to take apart the stuff I had built! I was promptly told to stick with standard # 2 Phillips in the future.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
DerbyDad03 wrote:

I have two screwdrivers I carry in my pockets whenever I'm working. The drivers have flat, Torx, Phillips and square bits because I never know what I'll run into. The bits can also fit a power driver. A good pocket screwdriver is hard to find and I found the best I've ever owned a W W Grainger. It won't poke a hole in your pocket when it's closed up with no bit in it.
http://www.grainger.com/Grainger/items/5PA35?Pid=search
I also carry a lot of other stuff in my pockets that keeps me from having to run back to the van for a tool.
TDD
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Robertson screws are pretty good but the ones with torx heads are really awesome. I re-pitched a roof once with adder trusses held on by torx fasteners that screwed into the original trusses. Long as they were, they never stripped. Unlike some Robertson screws I've used in building decks.
Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 13 Apr 2010 18:30:38 -0400, Wes

I bought a package of Torx head deck screws for erecting pump staging. It's nice to not have to push on the driver at all when you're up on a ladder and reaching as far as you can to fasten the pole braces. Expensive, but much better than Phillips or Robertsons.
--
Ned Simmons

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wes wrote:

A couple of yrs ago I built for my daughter's old cottage in Wales some new kitchen units. She wanted then out of solid wood, in the medieval style. The framing was from 4 by 2 with the tops in 2in thick all from cedar inc the doors which were 1in thick, boards some 20in wide. These boards were planked up when she was 6 and put by. I used them for her some 19yrs later!!.The wood came from her school at that time as we had had the storm of the century and most of the school trees were blown down. I helped to clear up the resultant damage. To fix the frame to the top from the underside needed 3&3/4 in screws. I pilot drilled the 1st 2in through the framing then the remainder with ,would you believe my 1/2in car wheel nut air hammer. the screw heads were countersunk no3 pozidrive and nothing put them in better or faster. Thought it might just be of interest, as no other power tool would work to pull them up real tight. Didnt cam out any. ted in Dorset UK
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 13 Apr 2010 18:30:38 -0400, the infamous Wes

Yeah, my head favorites, in order of favor are: Torx, Robertson, Pozidrive (square and phillips), and Phillips.
For repair work a year or ten later, Robertson/square beats them all. A nail or screw pushed into the recess removes enough dirt and grit to allow the drive to remove the screw without stripping. I keep a camera lens puffer (rubber bulb with small brass tube for blowing) in the truck for things like that. It saves a whole lot of time and frustration when you don't have to drill out any hardened screw heads.
-- Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop away from you like the leaves of Autumn. -- John Muir
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

WhatHeSaid! Torx is your friend....
--
A host is a host from coast to snipped-for-privacy@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I dunno, I used quite a few pounds of square-drives putting up a shed. The drivers didn't wear like a cross-point/Phillips bit would, but quite a few heads stripped out or screws snapped off without driving home. This was with decking screws, U.S.-made at that. I've used a whole lot of regular-type sheetrock screws and didn't have that problem. Wore out a bunch of driver bits, but never had a head strip. Haven't seen stainless drywall screws or I would have used those.
Have a bunch of trim screws off of Fords I picked up in the scrap yard that had interesting threads, went into plastic parts. Were multi- start threads, one start was coarse and heavy, like a sheetrock screw, the other was shallow and thin. Hadn't seen anything like that before. Seem to be pretty resistant to vibration, have to tighten up the other trim screws after awhile, not those.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Apr 13, 7:08pm, snipped-for-privacy@prolynx.com wrote:

Yeah they do kind of a controlled bind-up but they are bad to strip out if you put them in and take them out more than a few times. May work better in wood than they do plastic.
Jimmie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@prolynx.com wrote:

It seems like all of the new electrical panels I'm coming across these days are using square drive screws or combo screws that will work with flat, square or Phillips drivers. I like the torque handling capability of the square drive screws and the absence of cam-out slippage.
TDD
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 13 Apr 2010 16:08:42 -0700, stans4 wrote:

Maybe there are quality issues between brands? I've seen it before with Phillips-head screws, where the amount of material forming the screw can be a lot less from one vendor compared to another. The 'lesser' screws just loved to snap when driven in, whereas the ones with thicker shafts didn't. These days I always buy fastners from real stores (not online) so I can check what I'm getting.

Seen that on doors before - I think it's so they can be screwed into different types of material while retaining strength.
cheers
Jules
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 14 Apr 2010 13:05:52 +0000 (UTC), the infamous Jules

All the local dealers carry are Taiwan-made GripRite screws. I lose very few of those, though. I wonder if stans4 was driving 4" standard tip screws into undrilled hardwood. I never lose screws going in, but have lost a lot backing them out after they've been in. Half the tip/screw is usually left in the hole when that happens.

As to screw reuse, if they're coated for pressure treated wood use, they're pretty much a single-use item. Everything else is good for as long as the drive head is usable. By using good and fresh tips in your screw- and impact-drivers, you increase that lifetime and save money down the line. (Tips cost under a buck.) And if there's one thing I've learned about stripped screw heads, it's that you immediately pull it out if you get even a slight strip (tip spin in the screw head) on the way in. Otherwise, you'll get it almost seated before it strips out completely and leaves you limited or no way to remove it. This applies primarily to flat and phillips screws, but other heads can strip, too.
--
STOP THE SLAUGHTER! Boycott Baby Oil!

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Stuart Wheaton wrote:

I agree. Less hassle getting enough torque. No phillips chatter.
--
LSMFT

I'm trying to think but nothing happens.........
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Normally I'd go with what you said but, I constructed two envelope walls (no studs having conduction from inside to outside for my machine room. The studs are tamarack, fine pitch was easier to use but I did finally resort to drywall nails, some that bent over. For a soft wood, tamarack sure doesn't know it.
Generally fine pitch is for steel studs iirc.
Wes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I'm sure there are exceptions. What the Gougeons learned first was that conventional wood screws didn't hold as well as sheet-metal screws in any wood they tested, probably due to their deeper and fuller threads.
--
Ed Huntress



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.