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.
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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.
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.
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.
On 14 Apr 2010 03:25:24 GMT, the infamous "DoN. Nichols" scrawled the following:
That was either a Type-17 or Self-drilling type tip, Don. Good Schtuff(tm)!
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I had seen and used only the self-drilling types up until half a decade ago, when I found the nice Type-17 tips and Robertson heads on better deck screws.
On Wed, 14 Apr 2010 13:05:52 +0000 (UTC), the infamous Jules Richardson scrawled the following:
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.
But sheet metal screws don't look like drywall screws. More likely they were Drill Point Drywall Screws, as shown at top of and one screen down in . The latter also shows (near the end, after the Trim Head Drywall Screws section) Auger Point Deck Screws that look somewhat like drywall screws. (With Type-17 point, as mentioned in the link Larry Jaques gave, .)
The screws you mention are for self drilling, self tapping holes in fairly thick metal. The commonest place you see them is for fixing steel roofing sheets to girders on agricultural/industrial buildings. They usually come with a washer with a weather seal under it.
Heh, I'm surprised that some here have asserted that it is the fine thread that's used on metal studs, coarse for wood. Not disputing it, just surprised that this would be so, as it would seem that the greater the ratio of major to minor diameter, the more grab possible on thin sheet metal.
In fact, there's a company that exploits this with some fancy sheet metal screws -- forgot their name, but I have a sample pack from them somewhere...
In re-thinking all this, pilot holes could be used to tailor any material to a coarse thread. Except that, well, altho pilot holes are good, they are also a pita.
I used to buy only fine thread, pretty much out of reflex, but now I find myself much more leaning toward coarse thread, overall. Plus, coarse threads are easier to tap, less chip binding it seems.
My understanding is that fine threads on big bolts is a torque/force consideration, for getting mating stuff really tight.
But, other than that, I think fine threads may be pretty much superfluous for general applications, unless, for example, metal studs really do call for a fine thread screw.
Bottom line is, I think I've convinced myself to dispense with fine thread anything, unless an application specifically benefits from a fine thread. Sure will simplify the organization/storage aspect.
I've always thought that the fine threads were for metal studs.
I've used the self-drilling ones in metal studs, but also in one room in my house where the ceiling joists were made of something resembling kryptonite. The normal sharp-pointed screws would just not screw all the way in. The self-drilling ones shot right in.
Also, for what it's worth, coarse threads require fewer turns to screw in, and therefore, go in faster.
Yes -- drill point bugle head blued like other drywall screws I've seen.
The first SELF-DRILLING in that list (just past "TYPE 25 POINT" is exactly what they were using. And given the application, they made sense. One tool (battery powered drill/driver), one screwdriver bit (Phillips) and the screw which did its own drilling. Not what I would have used to make a pretty job, but something which got the contract done quickly. :-)
The screws were guided by the pre-drilled holes in the replacement desk tops, and the steel which they had to drill through was probably about 12 Gauge or thicker. (I never tried to measure it, but those were *heavy* GSA steel desks.)
In case it matters, I'm in here from rec.crafts.metalworking, not from alt.home.repair, so what I regularly work with is likely quite different from what the ahr crowd (who is part of the cross-posting) does.
There are 4 types of screws typically used for drywall..
Coarse Thread from 1inch for pocket door walls to 3 inch for going over old sheetrock/plaster , multiple layers in firewalls ...For use with WOOD studs
Sharp Point fine thread..Same as above except for use in METAL framing..
Self Tapping fine thread , sams as above but for higher gauge steel like in exterior or load bearing steel framed walls..
Laminating Screws...Fat coarse thread 1 1/4 screws for laminating sheetrock on steel framed walls as in stairwells or elevator shafts where sheetrock thickness is an inch or more...
Other than sheetrock I use Torx...Square heads are good as well....
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