Help! Beginner Breaking Screws

[Alan Huey]

Lubrication always helps. Wax, Soap, etc. etc.
countersink larger also would help, but be careful not to oversize compared to your threads. You want them to bite for strength

[Jeff DeTray]

Thanks to everyone for the many helpful ideas. It's some consolation to learn I may not be a complete idiot after all and that the low quality screws may be a contributor.

Mark guessed correctly that I am attaching 3/4 stock to something else. After reading your posts, I did a bit of experimenting with scrap.

First I used the #6 countersink and a #6 screw, but I lubricated the screw with candle wax (the only lubricant that was handy). The screw broke.

Next I used the #8 countersink, a #6 screw, and candle wax. The screw did not break. Admittedly, I had the torque on the driver at a fairly weak setting, but I could feel the screw bottom out, so I think it "bit" into the wood.

I also tried the #10 countersink, a #8 screw, and candle wax. That also did not break. So using a larger countersink and lubing the screws will prevent breakage with these screws, but I don't know how strong the joints will be. It might be enough to go up just one size on the countersinks, but of course I have only the even numbers -- #6, #8, and #10.

I'll do more testing when it's not so late at night -- I don't want my shop noises to disturb the neighbors. More results then.

Interestingly, I discovered McFeely's for the first time just a few days ago. Perhaps it's time to place my first order.

- Jeff

[Don Eddard]

So using a larger countersink and lubing the screws will prevent breakage with these screws, but I don't know how strong the joints will be.

Jeff, I think you'll have plenty of strength even though the pilot holes are bigger. Especially considering you're gluing the joints, too.

[Chris Kennedy]

I'll pretty much echo the common thought -- the quality of your screws. I haven't had much trouble with the borg screws as some seem to have had, but I stopped buying them from one of my local hardware stores when I lived in PA. They were junk and snapped all the time (in pine!).

You may also have a defective batch. I had that happen once as well. I bought a box of screws from a very reputable lumber store near my dad's and started having trouble driving them in redwood with sizable pilots. I broke one when drove it by hand. I took them back and at first the guy was reluctant to believe me. Then he drove one by hand and it bent. They pulled the lot from the shelves to test them, and gave me replacements from a different batch. They were fine.

Cheers,

Chris

[Danny Thompson]

If you are in a hurry (no time to mail-order), try the coated deck screws from the BORG. None has ever broken for me.

[Cliff Rohrabacher]

Wood Screws at the Borgs are all made from mouse droppings.

Their higher end wood screws are made from turtle droppings.


Metal processing is not simple or straightforward. Different processes will produce qualities of steel and brass that are different from each other and often in dramatic ways. Then there are the mechanical forming processes used to form things like screws.

The BORGs all use the suppliers who make all their purchasing decision based on cost as the sole factor. Then the BORGS make their decisions based on cost alone. And when you go to the BORG well you are either there because of a "cost first" decision or it's just the place you know. Either way you are taking a hosing on things like wood screws.

Which means you are getting the worst of the mouse dropping screws that humans can make.


Interestingly I have found the Deck Screws at the BORG fo be far superior to those I can get from the local Ace hardware.

Go Figure.

[Christopher Foote]

The second time I broke the head off of a screw in a project (red oak) that I had invested a lot of time in was when I gave up on wood screws. Drilling an oversized hole greatly reduces the strength of a joint. I bought a wood tapping tap from lee valley and use stain-less steel machine screws from the hardware store. It works great. Also for fine furniture the thickness of the piece of wood you are screwing into is generally less than 1". Even with a well engineered screw there is not a lot of depth for holding strength. I got the idea from reading one of David Charlesworth's books, he mentions that he taps holes for many of the hinges he installs on his furniture.

Christopher

[Jesse Cloud]

Above advice is good. However, the glue will give you way more strength for a longer time than any screw. With 'glue and screw', the screws are there mainly as clamps until the glue cures. Bottom line - if the joint closes tightly, don't worry about it.

And I'll add to the chorus that McFeeley's screws are worth the money and the catalog is very educational, too!

[Don Bergren]

My local Ace Hardware carries GRK brand screws and I've found them to be excellent. I've been a McFeely's users for years, but the GRK's have won me over and I am phasing out my great McFeely's square drives in favor of the great GRK brand. I haven't had any problems in hardwood's so far, but proper sized pilot holes are a must with any screw.

[Bill White]

All good tips but you should also lube the screw with bee's wax or other good lube before driving screws into hardwood. Bar soap works in a pinch but it can cause the screws to rust and make them difficult to remove if ever needed. A little lubricant will probably solve the problem with the screws you have.

I know that this may sound too hi-tech, but I have a toilet bowl wax sealing ring in my shop fridge. Any time I need to drive some screws, out comes the old bowl ring. Voilla!!

Bill

[Mark Smith, too]

Next I used the #8 countersink, a #6 screw, and candle wax. The screw did not break. Admittedly, I had the torque on the driver at a fairly weak setting, but I could feel the screw bottom out, so I think it "bit" into the wood.

I also tried the #10 countersink, a #8 screw, and candle wax. That also did not break. So using a larger countersink and lubing the screws will prevent breakage with these screws, but I don't know how strong the joints will be. It might be enough to go up just one size on the countersinks, but of course I have only the even numbers -- #6, #8, and #10.

If DeWalt sized their drill for softwood, the next size up drill is only about 1/64 of an inch larger than what is needed for the smaller screw in hardwood. So an 8 drill should only be 1/64 larger than the recommended size for a 6 in hardwood under the above scenario.
This means you'll get plenty of grip using that approach. Glue will give you a joint that won't pull apart.

Again, drill a clearance hole through the top board (drill it after creating your first hole so things line up) and you can probably get away with the 6 drill for a 6 screw.

[Harry Goodwin]

Somewhere some time others have used my tip. If you are in a shop use a wax ring for toilet for lubrication. works great and cheap. Bees wax for off site instllatioins. Harry

[Peter M. Spirito]

I set the clutch on my DeWalt to run the screw almost all the way in. The last half-turn I do by hand. I use McFeelys screws exclusively.

[Mike Henderson]

Spax are good screws, also, and I can get them at a local hardware store. If they're available in your area, buy a small pack and give them a try.

Mike

[Lon Schleining]

Can't resist jumping in here.

I've driven a lot of screws; a very wide variety of both different screws and different woods. I mean thirty years worth of screws. I quit using tapered bits decades ago. I also quit using the combo countersink and drill bit sets about the same time.

The countersink hole you get with these bits is poor to say the least compared with a nice clean Forster bit hole. The taper means that the hole is too small in some places. The size might be fine in more forgiving woods like pine and poplar, but not so good for oak or maple. Most importantly, though, IMO, is that the 'top' piece; the one in which you are drilling the counter bore, should have a shank pilot hole large enough for the screw to freely drop through. The taper/counter bore bits don't drill this most important hole the corrrect size.

The idea is to pull two pieces of wood together. That will happen if the threads grab only in the 'bottom' piece and not the top one.

I use three different bits every time I drive a screw into a piece of wood. (Yes, I change bits three times for each screw size, and no it is not tedious, at least not for me.)

Hole#1 -- First, I drill the counter bore hole sized for the plug I'm using.

Hole#2 -- Then I drill a shank hole through the 'top' piece. This is a hole large enough so that the screw drops through it without slowing down.

Hole#3 -- Third, into the 'bottom' piece, I drill a pilot hole sized for the threads, the screw material, the screw size and the wood I'm using; taking all four into account. (see below)

I use a dial caliper to measure the actual shank diameters of the screw first where the upper smooth shank is, then at the threaded shank area. (That's why there's a knife edge on part of the caliber jaws; so the caliper fits in between two adjacent threads.)

This is the diameter for my upper and lower pilot holes in most cases; usually a size larger for the smooth shank area to give it lots of clearance. I pluck the drill bit out of the index using the same caliper setting and off I go.

But if I'm using brass (soft) screws in hard maple, (extreme example) this is only a starting point for the threaded shank pilot hole.

In my opinion, the threaded shank pilot hole should allow you to drive the screw with a screwdriver (yes by hand) quite easily without lubrication. In pine, (soft wood) this pilot hole might even be a touch smaller than the shank. But in hard maple (just about the hardest wood most of us will encounter) the hole will have to be larger; up a size or even two larger, especially if it's one of those @#$%$## small brass hinge screws for that fancy figured maple jewlery box.

If the screw is hard to drive by hand, you risk twisting it off. At first try two or three different sized holes and see how it feels. (If you're worried about the pilot hole being too large, try to pull the screw out with a claw hammer. Trust me you won't be able to do it. I'll break off every time.)

Finally (in closing much to the relief of the audience) my habit these days is to drive the screw almost all the way home with my trusty cordless. And I mean almost. Then, I tighten 'er down by hand with this really good and carefully sized screwdriver I have just for that size.

For those who (yes, I was almost finished, but not quite) like a lot of you are groaning at going to all of this trouble just to drive a screw into a piece of wood, just remember I've driven enough of 'em to finally figure out what works (for me, at least) every time.