Forstner Bits

[CS Bespoke Furniture]

Hey everyone, need some advice on Forstner bits.

I currently have a 40mm bosch knife edge bit and it burns like crazy. I heard recently the knife edge bits are much better when below 25mm. So I've been looking around and have come across a few different designs. A wavy edge bit, a saw tooth bit and a carbide bit. They all seem to offer the same thing for very similar prices.

Im using the bit 99% of the time on hardwood (Ash and Oak) and sometimes on end grain. Does anyone have any advice or light they can shed on my dilemma please?

Also don't want to spend over £20 on a new 40mm forstner if I can help it. recommendations would be appreciated.

Thank you
Chris

 

[MattRoberts]

What speed are you cutting at? And how blunt is the bit (how much use)?

 

[sunnybob]

perfect timing, just watched this a couple days ago.

https://youtu.be/LeBFcCTXZkA

 

[woodbrains]

Hello,

Sawtooth bit on end grain, you need some form of gullets to relieve the sawdust. The wavy ones run a bit cooler on side grain cutting and give a nice, smooth wall, but are no better than regular Forstner bits on end grain, in other words, hopeless. Carbide for man made boards.

Mike.

 

[Ttrees]

Marius Hornberger has just done a recent video with some on the subject too.
Interested to see what some of you folks (on a budget) are using.
Can some cheap ones be fettled to work nearly as good?

I don't even need any yet, but now have an excuse since I got a lathe

Watching with interest
Tom

 

[pollys13]

I have some Fisch wavecutters which are very nice but not cheap. Also they are limited by available extenders for them. I also got some Colt again, top quality and quite expensive but a selection of extenders are available for them.
Trend do a good price on a beginners set, about £30 I think on Ebay.

 

[MikeJhn]

Changing from the Trend bit to a Weldon tools offering was a revelation on how good a bit can be.

Mike

 

[OscarG]

Changing from the Trend bit to a Weldon tools offering was a revelation on how good a bit can be.

Mike

Yep, I had exact same experience.

I was used to the bit burning with my Trend bits, taking forever to cut. I bought a 22mm single Forstner from Wealdon and the difference is staggering, cuts through anything like it's going through cheese, no burning and clean as a whistle.

 

[Bill Derr]

Are these the best type for mdf and veneered ply?

https://www.wealdentool.com/cgi-bin/sh0 ... _2dFS_2f10

 

[Beau]

I use the Fisch bits and really cant fault them. Clean fast cutting in most woods. Just drilling out some end grain today with them and was pretty quick cutting but does not track a nice straight line.

 

[custard]

Are these the best type for mdf and veneered ply?

https://www.wealdentool.com/cgi-bin/sh0 ... _2dFS_2f10

For the odd hole they'll work fine, but if you work a lot with sheet goods you'll find there's are (much) more expensive versions from top end manufacturers like Famag designed for sheet goods that will hold their edges far longer. The trick with any Forstner is to learn how to sharpen them, it's not hard but it makes all the difference. If you drill into end grain you'll need to re-sharpen regularly, and even on a brand new drill you can generally improve the edge and produce a cleaner cut by some judicious honing.

The other issue with Forstner bits is if you want matching plugs to fit the holes precisely, if that's the case then you're again better off digging deep and going for something like Famag.

 

[MikeK]

Are these the best type for mdf and veneered ply?

https://www.wealdentool.com/cgi-bin/sh0 ... _2dFS_2f10

I have a few Bosch straight side Forstner bits like these and it takes a while to drill through MDF. I was boring some 20mm and 25mm holes in a sheet of 19mm MDF, and I had to stop every few millimeters to clean off the cutting edge of the bits. They were new, so I thought they would be sharp enough, but didn't work so good. I think I'm going to buy some Fisch wavy Forstner bits.

 

[kevinlightfoot]

I use Clico Forster bits they bore beautifully clean holes and are accurately sized,these I generally use for fine work,I also have a set of sawtooth bits for general everyday use in manmade boards or rough timber.It is though necessary to keep them sharp and to use a slow drilling speed to avoid burning or overheating of the edge.This is just my way and others will opine differently.I buy my forstner bits from Thomas Flinn not cheap but I think they are very good.

 

[Simou1]

One of my boys bought me a set of Festool Zobo bits for my birthday. They are superb and produce shavings that are almost translucent. The removeable centre point is on a taper and the set includes a longer one for angled cuts and a drill bit to ensure absolute accuracy when boring from both sides.

They are lovely to use and are equal to the two Famag forstner bits I bought years ago whilst serving in Germany.

 

[Ttrees]

One of my boys bought me a set of Festool Zobo bits for my birthday. They are superb and produce shavings that are almost translucent. The removeable centre point is on a taper and the set includes a longer one for angled cuts and a drill bit to ensure absolute accuracy when boring from both sides.

Those sound very useful indeed 8)
Here is the cheap way I have been doing that
Its a bit backwards though :?

Sounds like you make a flat bottomed hole with those

Tom

 

[MikeJhn]

Are these the best type for mdf and veneered ply?

https://www.wealdentool.com/cgi-bin/sh0 ... _2dFS_2f10

I used those on four recent MDF wardrobe doors, after twelve holes they still seem just as sharp, with the Trend it only took two holes to notice the difference.

Mike