Driver Choices for Confirmat Screws

Experiences using battery-powered and air-powered impact drivers to drive Confirmat screws, and some thoughts on screw selection. April 18, 2006

We are trying to improve how we drive our confirmat screws into the cabinet box. We use 3/4 inch thick prefinished plywood boxes with 1/2 inch thick prefinished backs. We drill a pilot hole around the perimeter with a 5 mm bit in an air drill, then follow this up with a step confirmat drill. We've tried doing this with just the confirmat step bit, but depending on the configurations of plys in the plywood core, it sometimes drifts or goes askew.

Driving the confirmats home is what I am trying to optimize. Electric drills are quite a bit faster than battery drills but not as convenient. It was suggested that we consider a battery driven impact driver. I went to Tool Crib to see what my choices were and that is how I ended up back here. There are too many choices. Has anybody used battery driven impact drills and do they work? Which models would you recommend? Can you suggest another method altogether? I would optimally like to see this done with a flashlite shape drill attached to a tool balancer from above. Any ideas?

Forum Responses
(Cabinetmaking Forum)
From contributor A:
I use a Makita 14.4v impact driver. It was a revelation compared to just using a cordless screw gun (I'm ambivalent about the light that comes on and illuminates the area around the screw you're about to drive when you squeeze the trigger). Bear in mind that it only drives - it's not a drill. I like the balance of the Makita more than other manufacturers. I feel that the 14.4v is a better compromise of the power to weight ratio than 12 or 18v. Also, if you buy it as a kit, each tool comes with 2 batteries and a charger for little more than the cost of 2 batteries alone (remember that extra batteries are about $80 each). When it's time to replace worn batteries, I just buy another kit. When I got this driver, it came in a kit with both a 14.4 drill and an impact driver. Honestly, though, there is a limit as to how many cordless drills one man needs.

From contributor B:
We are using an air impact driver, model # BT302, sold by Beaver Tools to drive our confirmats. We used to use 18V cordless drills, and the air impacts run circles around the previous operation. We also have the guns suspended by a tool balancer. They work fantastic!

From contributor C:

I've been using a Makita 12v and it has plenty of torque to drive home a confirmat. In fact you have to be sure to release the trigger after just a couple of impact cycles (fraction of a second) or it will mushroom out the end panel. I also use it for installing - it has much more torque then an 18v drill and is much faster.

From contributor D:
We've been using the 12V Makita impact drivers for years. They are light and have plenty of power to drive the confirmats. Check out Tyler Tool on the web. I don't think there is a need for balancers with this tool. We cut nested so the 7mm holes are right on target. The edge bore is done on a Morbidelli boring machine with 5mm bits. We modified the boring machine by adding removable fixed stops for referencing the front edges of the box. In MDF we go with just a little bigger bit since MDF is so prone to separation. Bits are available from European Tooling.

From contributor E:
Those impact drivers are great. I got the 18v and it has more power than I need. To test it out I drove a 3" self tapping screw with washer head into a 6x6 pc of red oak with no pilot hole. It countersunk it effortlessly 1/4". I was sold. I failed to mention it was a Dewalt. For drilling into plywood or particle board, 12v or 14v is surely plenty. Yes, it is a little heavy and no, I would not want to lug it around all day. I use mine to screw cabinets to the wall through the nailers without having to pre-drill.

From Brian Personnett, technical advisor CNC Forum:
We use both the Beaver model mentioned as well as another from Cooper Tools, Air Power, I believe. I had two giant beefs with battery operated tools. 1. They're too heavy. When we first started I was the one out there all day lugging the thing around, and it just wore me out. 2. The speed - battery operated drivers are just too slow. Snce switching to the 5mm confirmats, we haven't seen the need to use the impact mechanism. With the larger 7mm, it was a necessity for us.

From contributor F:
Hafele's "Zentrix" with sleeve/spacer assembly is made to fit on an electric drill. With it you drill the complete hole in one operation, square to the case and accurately spaced from the edge. Regular battery or air guns happily drive 7 mm confirmats into these with no trouble.

From Brian Personnett, technical advisor CNC Forum:
The impact mechanism I was referring to was on the Beaver driver. We could not get the Beaver's standard driver to set the heads of the confirmats flush. We have never used the Zentrix bit - well.....I should say I used it once. We bore on a P2P, so the holes that we have are not countersunk. They are however fairly "square to the case and accurately spaced from the edge." Battery operated drivers will sink them fine.

From contributor F:
The Zentrix is certainly low-tech next to a P2P or CNC, but it sounded like the original post was using two separate hand drilling operations to get a hole that he could get accurately in one pass with a Zentrix. We just bought 5mm confirmats, and will do some testing with them - occasionally we get some "pooch-out" sinking the 7mm screws into prefinished 3/4" that I'm trying to avoid.

From Brian Personnett, technical advisor CNC Forum:
To contributor F: In my admittedly crude testing and evaluation, basically I put boxes together and dropped them, and hit them with a hammer, and lastly used a fork truck to simulate a load being put on the shelf. I found the 5mm confirmats to actually hold better than the 7mm's.
I also experienced the bubbling or pooching - this was particularly annoying on the bottom of wall units. I also one time did a giant job of cubbies, and it was a major issue. Since switching to the 5mm's, it doesn't happen.

The main reason I went with the 7mm's in the first place was due to AWI's specs. Since switching, that's never been an issue either. Most of the architects that I deal with are guys I've dealt with for years, but I do have the occasional PITA, and I haven't ever been questioned by him either. In my submittals, I usually gussy the language up a little. I don't give the size, I just label it "Confirmat European Assembly Screw" If it's European, it has to be better, right?

From contributor G:
I'll share a couple of tips that have helped me. First, if you have a construction boring machine, you can use this to drill your confirmats. I use 5mm and 7mm drills. It is 2 different operations, but it works like a dream. Second, like others, we use an air impact – it is super fast. I actually have the guys use a cordless until they get the hang of it, then move them to the air. Third, I use screws from Fustabo. They are in CA, and sell through distributors. Their screws have a couple of features that I really like. First is their combi-head. You can use a #3 pozi, a #2 square drive, or a combi (square/phillips) driver. I prefer square drive for other screws, so we don't have to change bits often. The second feature that I like are the hi/lo threads. It seems to give us much better bite. These things don't tend to strip in softer materials and have excellent holding in plywood.

From the original questioner:
I just bought a Milwaukee 14volt impact driver. The guys say it's a bit faster than the way we’re doing it but it sounds a machine gun going off. This work station is right outside my office so we may be doing some more research on this one - or else relocating this particular pond somewhere else in the value stream.