Forstner bits cut larger holes (up to 76mm or 3 inches that i’ve seen). The difference between them and a holesaw bit is twofold

I also don’t really worry about the coating. The drill bits I have (see images) coated in titanium nitride (yellow – see images). All the coatings are designed to extend tool life but I typically buy on price to be honest.

Helix angleaviation

Personally, in my workshop I use metal drill bits mostly because they come in large sets (metric and imperial) and are easier to sharpen.

Having said that the hole usually isn’t the cleanest hole you will ever drill. And for this reason I don’t use them much in the workshop. When I used to work in construction and go ‘on site’ a lot, the spade bits got quite a workout.

Their best use is drilling the same hole again and again, for example screwing on the back of a cupboard or production runs. I didn’t like them personally, even expensive ones. The constant re-adjustment was a real pain.

End mill helix anglefor aluminum

Image

As you can see in the images the hole can get clogged easily but it didn’t matter a great deal the hole was clogged or not. And they weren’t too expensive.

I’ve never bought an individual holesaw although it seems you can (see here). Having a set gives peace of mind. If you do want to try and buy individual you’ll need one with an individual arbor with pins like this. Don’t buy ones that work any other way!

Highhelix end mill

A Bradawl isn’t a drill bit. In fact it looks like a screwdriver. The difference being Bradawls have a sharp point at the end instead of a flathead or philips head tip. They are used to make a point in your work, which helps centre the drill bit you are using.

Image

Wikipedia says that the angle is 118° however I don’t change the angle, I just clean them up when sharpening. I was taught in trade school, the less you do, the better.

To stop breakout, simply put a piece of scrap wood under or behind what you are drilling. It needs to be secure and have no gap between it and the piece you are working on.

Another tip is it helps to keep a good full set somewhere, that way you can always drill the right size hole and don’t get stuck during a job. I have a green Sutton set at work and an Alpha set at home.

Because of this, they serve a very specific purpose. You could use them to drill holes but their sizing is measured by the size of the plug so you might find it hard to get the size hole you want.

Buy good quality here. There are cheaper versions available that use different methods, with different thicknesses of holesaw cutters. They are crap.

They work as intended. If you do want a particular size hole then I would put it in a pedestal drill. This will privide the control you need for a precise hole.

You can get holesaw bits with tungsten teeth. I advise you to stay away from them! If you hit a nail, they are broken. If the tungsten comes off, it is broken. The bi-metal holesaw bits are much better, and last a lot longer.

I haven’t had experience with tapered so I can’t speak to their effectiveness. But the straight ones do cut straight dowel.

But if you don’t have one or can’t use one for a particular job, then I use a square on two angles (front and right hand side) to make sure the drill looks straight before drilling.

Becasue of their unique shape, they don’t really have any other function for woodworkers. They are also expensive so you wouldn’t use it for a different purpose either.

You can get sets of wood bits in a hex shank quick change for your impact driver although I don’t recommend them. The accuracy (which is the biggest benefit of the wood drill bit profile) is gone because the slight looseness of hte quickchange chuck causes the bit to wobble when spinning.

A Reddit for Machinists of all varieties. From Old School conventional guys, to CNC Programmers, to the up and coming next generation.

To stop breakout with a holesaw, drill in one way until you can see the centre drill bit, and then finish your hole from the other side. This will also help you cleaning out your holesaw bit. You can do this technique too with the spade bit when you can see the centre tip coming through the other side of the timber.

Helix anglecalculator

This specialty bit is designed for the pocket hole jig. The reason for the shape is to drill a clearance hole (the large bit) and a pilot hole (the small bit) at the same time.

Plug cutters are different to all the other bits we have covered in the fact that they are concerned with the ‘plug’ not the hole that is left in the timber.

Handy if you ever need plugs, but I must admit I rarely use them. If you need plugs buy the one you want individually. You can also buy a set with most sizes in it.

I don’t use them now, but when I worked in the trade I new someone who had them. They were nice to have but after a while your doing so many that your eye just gets good enough to get the middle each time.

The idea is that the cage around the bit is the right size for your hole, and then you simply drill. With no mucking around about trying to make sure the hole is in the middle.

Image

I tend to use Forstner bits in the high school workshop becasue holesaw bits get hot and getting kids to take out the ‘hole’ in the holesaw bit takes time. It’s easier for them to clean up their mess.

Good to have around although sometimes can’t give the quality of hole required. I have a set of Irwin spade bits at home that hardly ever gets used, but it does come in handy sometimes.

We are doing a long run production job at work, and my boss got me a bunch of various endmills to use to test to see which I preferred. I can understand various endmill coatings, but whats the deal with Helices? I would imagine a higher helix is better for chip breaking? (More cuts per length?) How would that help with deflection? can I feed it higher? Or just take a larger depth of cuts? Are there formulas for this?

There are two different styles of plug cutters. Straight and tapered. A tapered plug has a slight diameter changed and is designed to make it easier to put in the hole. Straight ones are straight.

These bits save time and get better accuracy as only one hole needs to be drilled for each screw. They also tend to come with a little steel ring that acts as a depth stop that is put on with an allen (hex) key.

Buy and use brand names here as they get used a lot. Here’s a good place to start for a full set and here’s what I keep in my office to replace broken bits.

On the negative side, you can get some smoke from them when in use due to the friction created by the hot spinning bit and the material so they do need to be semi-regularly sharpened.

These ‘twist’ bits are the drill bits I use 95% of the time. They are easy to use, come in good size sets and can be sharpened pretty easily.

Once you get a good set, you can replace bits individually. A good drill bit set is a good thing to ask for as a present (Birthday, Christmas, etc.).

Great to have in the workshop for those occasions where they are better than metal bits, but not 100% necessary. I learned while writing this that you can get specialist larger than 13mm brad tips as well, but for larger than 13mm I like to use a Forstner bit.

They look a cone with a hole in it. And because of their shape and cutting action, there is no chattering. They create perfect circles every time.

These drill and countersink in one bits have been around in a while. They are a bit fiddly and in my experience need to be re-adjusted semi-regularly (because the drill bits slide in).

But hole saws are tougher. These ones (which is the style that I have) can take some beating and even a nail or two in case you decide to remodel your kitchen.

I do keep some wood bits and use them mostly on the pedestal drill to help students who are drilling repetitive holes. The tip on the wood drill bit removes the need for the bradawl, effectively removing a step and making the process faster.

Teaching Woodwork is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Holesaw bits can get quite big. 121mm (4 and 49/64 inches) is the largest ive seen but there could be larger. Holesaws keep the hole section which is the difference between them and the forstner bit.

But for fine woodwork, they aren’t suited I find. They turn the hole into wood shavings like the Forstner bit but their construction means they don’t have the support at the drilling face.

Variablehelix end mill

The good news is that these work a lot better than the star pattern countersink bits. Every hole I did (as long as I kept the drill relatively straight) was a circle.

Helix anglevs leadangle

Better off with a smaller range of bits than a cheaper set. Although a good set like this does make a good christmas/birthday present for someone that doesn’t know what to buy you.

The main thing with drill bits is the steel that they are made from. Better quality steel will last longer. But it’s hard to compare this from different manufacturers.

Plugs can be used to fill screw holes for finishing (instead of putty) or for making items like toys and other fine woodworking. They are extensively used when constructing with the pocket hole method.

It can also help to have someone else (who has a technical eye) to check your drill by sight to make sure it is 90° to your work.

But the truth is they didn’t always work properly. They often created a ‘star’ pattern, instead of a circle. The reason being is that the star countersinks tend to chatter and jump around when spinning at speed.

It came in the mail (from eBay) and it works. I didn’t realise exactly how big it was. You can see in the picture in comparison with a AA battery.

You don’t need these (you can use holesaws to drill large holes), but they suit me perfectly in the workshop. They don’t need to be cleaned out after every hole and they are also the best option for boring holes.

Spade bits are great if you just want a hole in something. The length of the bit allows you to drill quite a deep hole, and the point does allow you to start the hole precisely.

The only time I had an issue with drill bits is when I bought a couple of hex shank sets on eBay (no brand) and they were rubbish out of the box.