Thread: Forstner Drill Bit - How I love Thee (WIP)

Looks good. Great idea.

I love my forstner bits.

I have a number of them in just the right sizes for particular jobs.

I 2 that are the right size for 2 of my wood turning chucks to bung a hole in my bowl blanks big enough to go straight onto the chuck.

Also have one just the right size for Tea-Light candles for making turned candle holders.

I have another 2 that are the right size for making salt & pepper grinders.

Good idea.
Re the narrow edge. I'd leave it, just be careful when you move house or crash it into things.

Must be decent bits to cut into end grain like that.

I really do need to go and get some decent Forstner bits, can anyone recommend a brand etc?

Colt (M2 steel) - you can get a set from Carbatec, but I buy them individually as required from Lee Valley or Infinity Tools (USA) direct.

These make every other Forstner I've ever tried look hopeless, go a very long time between sharpenings, and have been designed for easy sharpening when the need finally arises.

Also, I believe one of the local Festool outlets sell some decent Zobo branded forstners - never tried them myself though

CENTROTEC ZOBO (Forstner style bits)

Cheers

Reckon these will be ok:

16 Piece Forstner Bit Set : CARBA-TEC

The other ones are either HSS steel or Tungsten tipped however they are very expensive, but I guess you get what you pay for.

You said it - with Forstner bits you really DO get what you pay for. I had a set of those Carbatec ones to start with, and they are frankly rubbish. The steel obviously has a very high cheese content, because they need sharpening after every cut.

One I forgot to mention, which might be a good compromise between the best and the cheapest, are Carb-i-tool.

I'm pretty sure Carbatec sell them, but there are other outlets for Carb-i-tool products.

You're better off buying just the sizes you need in a reasonable quality, rather than get a bargain basement complete set of rubbish for the same money IMHO.

Originally Posted by Mr Brush

Colt (M2 steel)

G'day Mr B. I thought the same when I first investigated Colt Forstners, but they are indeed High Alloy steel. The Colt 5* Brad Points are HSS M2, and I think this is where I mislead myself.

Colt have released an HSS Forstner series, and instead of having the usual Brad Point pilot, they have a retractable 5* drill (which can be removed completely for the ultimate flat bottom). The supply of these is a bit unreliable though, it seems (I'm pretty sure that Colt do not manufacture these new ones themselves).

The other thing that Colt released last year was an increased size range for their MaxiCut Forstner range - right up to 100mm - at a price mind you.

Arry do yourself a huge favour and stay right away from those Chinese bits. There really is only one brand of forstner to purchase - there are a couple of others such as Famag and Fisch, but they are very hard to get, and not necessarily superior to Colt. If you buy those Chinese bits then you will spend your money twice, and that makes the subsequent (and better) purchase very expensive indeed.

As far as TC tipped forstners are concerned - TC is not able to be sharpened to the same level as steel (either High Alloy or HSS), and this means that your holes could easily be a little more ragged around the edges. Also, you'll need some diamond files to sharpen TC. Personally I would only go for TC if I was drilling that hole size in the hundreds, and was not after a really clean hole.

Btw, Colt also make a series of TC forstners, but in a more limited size range. They are aimed at commercial producers for use on CNC machines and come Left or Right rotation. They are for much much higher rpm speeds, and for use in the very abrasives materials used for kitchen manufacturing (primarily).

A word of caution on rpm speed: don't forget that the bigger the diameter of the bit, the higher the tip speed. This is a linear proportional relationship, i.e if the diameter is double then so is the circumferential tip speed at the same rpm. That means that you have to slow right down with bigger bits (and go to a higher torque setting) to avoid burning or a broken wrist (NEVER hand hold something like a 50mm diamter bit if it can be avoided).

HTH
Brett

While placing an order with Lee Valley, I came across this:

Lee Valley Tools - Important Announcement

These are the ones I have bought, and they are indeed M2 steel. I'm pretty sure they have "M2" engraved on the shank as well. Explains why they go so long between sharpenings.....

Originally Posted by Mr Brush

While placing an order with Lee Valley, I came across this:

Lee Valley Tools - Important Announcement

These are the ones I have bought, and they are indeed M2 steel. I'm pretty sure they have "M2" engraved on the shank as well. Explains why they go so long between sharpenings.....

Mr B, the manufacturer told me that they are not HSS M2, but high alloy. This is also evidenced by the fact that they will rust slightly, and in the same conditions the Brad Points (which are HSS M2) do not rust. None of mine have any stamp to declare the material. The Colt forstners that are HSS (MaxiCut Plus) have a retractable pilot drill and are twice the price.

There seems to be a wide misconception (which initially included myself) that MaxiCuts are HSS M2, but they are definitely not.

No, haven't used Famag - smaller range, bigger price, harder to get, but I don't doubt their quality.