I am slowly moving over to carbide for steel/iron as I replace worn HSS but now do a lot of my aluminium and non ferrous with carbide cutters that have a specific geometry for these metals. I also use carbide almost exclusively on the "hobby" CNC to make better use of the higher speed spindle and the resulting faster feed rates it allows.

Unlike the general purpose inserts solid carbide milling cutters are sharp so should put no more load onto the machine than HSS so you don't need extra power or rigidity. Also if it's an electric variable speed you can run faster which puts the motor in it's sweet spot. If you are wanting to try insert cutters than lighten the load by going with inserts for aluminium and non ferrous

The high spec 6 flute cutters are expensive so if you could half that to three flute that makes a reasonable general purpose cutter. You are also unlikely to be able to turn the handle fast enough to avoid too small a chip load so will end up with them rubbing which will blunt them. Also if used in a confined space you may not be able to clear the swarf which will result in recutting the swarf which again blunts the cutter. They are a bit more delicate than HSS so don't drop when changing and take care when touching off with a stationary cutter.. Looked after they will outlast HSS and more than cover the quite small cost difference.

This is a good video that shows that carbide if more than a match for HSS on a small machine even if run at HSS speeds I have posted this before when people say you cant get the speeds needed for carbide on a hobby/old machine

Edited By JasonB on 06/02/2023 08:05:12

Somtimes you get cast iron with chilled spots which can easily machine with carbide cutters. Recently I repaired a casting by brazing a piece on and the line next to the join was very hard but cut well with a carbide endmill and I have a small 25mm diamiter tip cutter which can remove surface hardness.

David

I sometimes use small carbide cutters on my mill and they work ok most of the time. I have thought clogged a couple of cutters using them on Aluminium Alloy. I’ve had to resort to popping the cutters in some caustic soda to clean them off!

Slower feed rate and lubrication should cure most of the clogging.

Tony

I had a SX2P and got used to cutting mostly steel with solid carbide cutters from 3 to 8mm diameter dry and held in an ER collet chuck. Since moving to a larger machine I still do the same except when cutting larger widths I use cutters from 12 to 50mm diameter usually held in an R8 collet. Use very little HSS in either the mill or the lathe although I trained using HSS many years ago.

I bought HSS(2x flute) and 2x carbide 4x flute endmill sets. I milled a lot lately and am so impressed with the carbide endmills(Have not touched the 2nd set), found the 10mm & 12mm very usefull, used the 12mm the most.
Have not break one so far even the 4mm.
I was surprised how long they last, and the ones I got alliminium don't weld to it, unlike whats happenning on the lathe.

With my hobby mill SX2P (2500rpm) and Warco 918 lathe (2000rpm) I use carbide cutters 99% of the time I only tend to use hss for making form tools. I have not had any problems with cutters running at slower than recommended speeds I just keep the feed rate and depth of cut lower depending on the job.The only thing I would say is to buy half decent cutters and inserts, I know some say they use cheap as chips carbide tooling and they are fine but that has not been my experience.

Jason,

I have got 2 types very decent AP?T inserts from a friend last year having a 0.8 mm nose radius. I was forgotten that I already bought a 12 mm holder for these inserts, found it in a drawer searching for the inserts. The next time I have to face some steel, I will test these 3 inserts under the same conditions. If it doesn't get any better, I will make some 12 mm boring bar holders for my DCMT070204, CCMT060204/8 and CCGT060204 inserts.

On a hobby machine, you can't utilise carbide cutters to the max. For that you need more power, more speed and more rigidity but you can still benefit from carbide.

For me, HSS is not out of the picture. For coarse threading, when I reach the limits of my lathe, I use a HSS threading tool because HSS tools don't break/chip that fast. My form tools are made from HSS because HSS is easy to grind and HSS dust is not so harmful.

Edited By Huub on 09/02/2023 22:37:43

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This may be a good time to mention that [in the best possible sense of the word] this might be termed abuse.

The flash of inventive genius came to someone, somewhere, when they realised that inserts specifically designed for one purpose could be ab-used to serve another.

This is the creativity of the ‘Amateur’ nicely demonstrated.

… Whoever it was, they surely deserve our thanks !

MichaelG.

Thanks for that, Jason

… and my belated thanks to KWIL

MichaelG.