Self Drilling Screws

Drill Point TEK Screws to Eliminate Pre-Drilling

Self Drilling Screws

Also Known as TEK Screws, Drill Point, Self Drillers and Self Tapping

Self Drilling Screws are used to fasten together steel or other metals and are typically used to join materials like sheet metal. The unique point or flute acts as the drill bit for the screw, effectively combining the screw with its drill bit. Since the self drillers drill their holes while creating reusable threads, they virtually eliminate the need to drill a pilot hole, tap it, and then install the screw. With these screws, you can do it all in one operation. Not having to pre-drill holes saves both time and effort.

There is some confusion regarding self drill screws and self-tapping screws. Every self-drilling screw is a self-tapping screw but with the added feature of a drill point instead of a sheet metal screw point such as an AB sharp point. If a screw will drill its hole, it is generally a self-drilling screw.

The TEK number of the tip distinguishes these screws. Generally speaking, this number has to do with the drill point's length at each screw's end and, by extension, the material thickness which the screw can reliably penetrate. The most common TEK Screw point is a TEK 3. Thinner metals such as 12 gauge steel are what most self-drilling screws are for, but they can pierce 20 to 14 gauge metals. We recommend a TEK 5 point for 14 gauge metals and below. So long as the unthreaded portion of the TEK point (pilot section) can completely drill through the material before the threads engage, you'll minimize the chance of the fastener binding and breaking.

For the self-drilling action of self drillers to work, they are made of a material that is harder than the material you are drilling. The most common material used in these Screws is 410 Stainless Steel. This grade of stainless will provide the corrosion and rust resistance of standard 18-8 stainless. However, it has been heat-treated (up to 40 Rockwell C) to ensure that the drill point will successfully pierce a given application's metal.

Installing Self Drilling TEK Point Screws in Metal

How to Install Self Drilling Screws
Installing Self Drillers Transcript

Scroll Down To Continue Reading

Bob: Welcome back to Albany County Fasteners - Fasteners 101. I'm Bob and today we're going to talk about TEK screws or self drillers. So let's get started.

So I have five different types of TEK screws here. The most common is the hex head that everybody uses. This has what they call a self driller TEK3 on it. The point is a TEK3 and basically that's the type of steel it can go through. This can typically go through about 12 gauge steel and I'll demonstrate that today

I have some galvanized channel. We're going to test that.

These are the same but basically with different heads. We have a flat head here with a TEK on it: for using it with wood, or attaching wood to metal. This is a panhead, phillips panhead. Same thing, a TEK3 on there.

Then I have a TEK5. You can see this drill point is substantially long. This is made to drill through structural steel and we're going to demonstrate that also today. It has very, very tight threads. These are 12-24. There's a little relief cut in there. That's what starts the threading in the steel.

I also have an alloy Buildex TEK5. This TEK5 is a usa-made product that has a chemseal on the outside of it to prevent rusting. These here that I just showed you are 410 stainless steel. 410 stainless has more alloy in it and less nickel.

As you can see, this is a magnet. They're very magnetized so in a saltwater application these will attract surface rust. If you use any of these screws where you have salt water in the air, such as at the beach, you will eventually see rust accumulation on the surface. So let's get started on testing these screws.

I have a piece of Kindoff here. This is approximately 12 gauge channel. It's used on many construction sites. This is hot-dip galvanized alloy 12-gauge.

I have a hex self driller TEK screw here and this is the the most widely used screw in the industry. This is a number 10 x 1 inch with a number three point. I'm going to demonstrate right now-oops-installing this screw in the Kindorf. I have a hammer drill here with a magnetic holder and let's see how this goes. This is 410 stainless going into 12 gauge.

I gotta make sure my vise is tight here. You don't want to go too fast, it's not a good thing. You want to keep consistent pressure. If you go over 2,300 RPM you'll burn the tip out and it just won't drill. You'll grab another one and you'll have to put another screw in.

We're almost there.

There we go. Now that's pretty heavy, 12-gauge. This is 410 stainless. If you're going into 14 gauge it'll track and stud very easily. This will go through. I wanted to test it on a heavier gauge since once you go below 12 you're now going into structural steel. We're going to test on structural steel but I don't think that this is going to do so well on it. You're really going to have to work that screw to get it in.

So we're also now going to try a TEK5 which is also made for structural steel; that's why it has such a long drill point.

That went a lot faster. That's a TEK5 for you and that is 410 stainless.

Now I'm going to test a TEK5 alloy Buildex screw which is an american-made product. These both are imports from Taiwan. Again you don't want to run the drill too fast; you go too fast you burn the point out.

So I would say that the import did just as well as the USA brand product. Now I'm gonna switch and we're going to try the structural steel.

So I have my 3/8" structural steel here. It's my test piece. We're going to test this standard TEK3 going into the structural steel. Core structural steel has a different makeup, they have higher psi, it depends on the structural steel you're going through. There's harder structural steel versus softer structural steel and you're going to get a result that will be different.

I haven't tested it yet, this is the first time, so let's give it a wheel and see how far we get into this.

Whoops. Gotta grab my screw. I'm applying a little too much pressure but it seems to be doing a pretty good job. Not bad. I'm pretty impressed with that.

Now I'm going to drive another TEK5 stainless steel 410 screw; we're going to test this one also.

It did excellent. Perfect. Another thing you have to think about with TEK5: they are always longer so you can't use them in tight spots. TEK5 are a minimum of 1-1/4" long and go all the way up to four inches.

Now I'm going to use the USA brand product which is alloy with the coating. This is a TEK5 also.

Oops. I have another one here. The key to these screws is that you don't have to pre-drill a hole and then thread the hole for a screw to go in. It does it all in one shot.

So as I demonstrated for you, you can see that a TEK3 and a TEK5 can go straight through structural steel. There is possibility in a TEK3 that you will have the screw heat up and possibly bust. With a TEK5 they're actually made for this application. So if you're going into metal studs, let's just say, 16-gauge, 14-gauge, 20-gauge, these screws will go through there like butter. I'm showing you an application where you're going through much heavier pieces of steel and if you can go through this you can go through anything lighter much easier.