End Mill chamfering bit, 90deg

Afternoon All,

Anyone know where I can buy a 12mm dia, 90deg. chamfering end milling cutter?

The usual UK sources don't appear to stock them, and that well known on-line store has plenty,, but they're all located in China.

i ca

APT do chamfer mills or I use their Drill Mills which will chamfer, both available in 12mm

Edited By JasonB on 10/04/2023 16:58:47

I used a carbide burr, a lot cheaper and also from APT.

Thanks guys,

I knew someone would know a source.

At a pinch, use a countersink.

I must admit to not being familiar with the Drill Mills mentioned. My assumption is you can drill and bore an accurate hole all in one go? There must be a catch as I normally find there is with anything that promises to do several things at once - if so what is it? I guess they are ideal in CNC environments but what about hobby use? Any thoughts appreciated.

Regards Mike

Well knowing that a lot of model engineers don't like putting their hands in their pockets, the burr and making do with a CSK being classic examples I find it a good compromise as I don't tend to do a lot of chamfering.

It does come into its own on the CNC but you can still use the one tool to spot drill, countersink, chamfer and do Vee groves and engraving as well as being able to drill down into a pocket and then start enlarging it buy using the sides like any other milling cutter.

I've probably used it most as a robust engraving tool and secondly to chamfer. This collet rack is an example where I did the lettering and pre chamfered the edge of the holes before opting for a standard 3-flute cutter to do the holes but opted not to do that with the same tool as I had a board below, would have been OK on a through hole. The 6mm suits me as most of my work is fairly small and I can get closer to internal corners with the smaller dia.

This page shows the pink icons of what can be done with just the one tool. If you are wanting to do something like a large 8mmx 8mm chamfer then the chamfer mills would be the better bet as they are a lot more rigid as there are no flutes above the business end. CSK and Burr also tend to have smaller dia shanks so may not be as rigid for large chamfers or need more lighter passes to get to final size.

Thanks for that Jason, very informative.

Nice job on the Collet rack as well!

regards Mike

Having a cutter grinder I have modified an old 1/2" end mill for use as a chamfering tool. Yes we engineers are tight with our money !

The price for the 12mm mill drill certainly caused a sharp intake of breath here. I think most model engineers must have a bigger edge tool budget than me.

Martin

That's another reason I use the 6mm one

But looking at the whole picture it is a lot more robust than your average engraving cutter so less likely to get broken, Two cutting edges so should last twice as long if not damaged and same two cutting edges mean it can be fed faster so machine is not running for so long all of which go some way to balancing out overall cost.

Edited By JasonB on 12/04/2023 13:12:22

I admit to using a countersink - one of the chunky 2 cutting edge ones with an 8mm shaft. Not sure why its looked down on though?

I used a V shaped wood router bit. They have tungsten carbide cutting blades.Did the job

I think a lot comes down to how much you need to do and the size of the chamfers. I the past I've used a countersink, a spot drill which works quite well and will also do Vee grooves, have a two insert little hogger set where one holds the inserts at 45deg and that is quite good but can't get into corners. I have also ground a bit to fit a flycutter that worked well but was a little slow being just one cutting edge. And if all else fails tilt the work or use a file.

Now I have the Chamfer bit that's what I'm most likely to reach for as it does the best job for me.

Thanks Jason, I was wondering what faux-pas I was commiting!

I used the same for 45° milled chamfers. For a long time I had an old slot drill that I'd ground to a 90° point with clearance behind the cutting lips - that worked well, also for countersunk slots and suchlike, but I lost it sometime in the last 20 years or so.

I'd make another, except I don't currently have a good enough reason to repurpose a decent slot drill.

Thanks again for the suggestions guys,

I'm going to try a 1/2" shank 90deg. router bit. Should be rigid enough I think.

I’ve tried router bits in the past and just about got away with it. They are far too fragile for use on metal, at least the one I used was. It was consigned to the round filing cabinet after use …

Edited By Vic on 13/04/2023 16:49:38

For small chamfers I use a ball end mill and just use a little bit of maths or CAD to calculate the offset from the edge to get a good 45 degree representation. The larger the diameter of the ball end, the closer the cut gets from an arc to a straight line.

Jim.

Edited By Jim Guthrie on 14/04/2023 08:42:13