Solid carbide end mills

Has anyone used miniature [1/8] solid carbide end mills for cutting ports? I have some ports to do and thought about buying one of these. My FC3 cutters are a bit blunt. I may have a go at sharpening them on my Quorn but it's getting a bit small to see what I am doing.

I have used 2mm and 3mm solid carbide cutters with great success for cutting ports, I obtained my cutters from Arc Eurotrade and was pleased with both the quality and speed of delivery, no connection to company just a very satisfied customer.

I use them all the time especially on hard steel and castings which may have hard spots etc just run them at a slight faster speed it helps.

David

I decided to make my own loco wheels from solid rather than using cast so have milled eighteen spoked wheels. Used 3 mm carbide initially for finishing but found the speed on the SX2P limiting and bought HSS in packs of ten from Amazon, worked well enough to convince me that HSS was my better option. I did break a number but at the price I wasn’t bothered and most broke due to the rough cut out causing too big a cut and poor swarf clearing in the setup.

Not 3mm but I was using a 4mm solid carbide on steel yesterday, it was a 2 flute really intended for aluminium but it was the only 4mm I had. Ran it at 2500 rpm and 20 thou cuts with no problems at all.

Hi, thanks that's good feedback. I was worried about breaking one in the port because they are very brittle.

Check manufacturer's recommended speeds, if you can't achieve them you will just abrade your endmill.
I've used 0.6mm carbide endmills but at 30000rpm and could probably have used a bit more speed.

my Amat 25 mill does 3000 rpm on high speed and 1500 on low speed. I don't know what the recommended speed for a 1/8th cutter on gunmetal would be. It would be 3200 rpm with HSS on mild steel. Tubal Cain says feeds must be kept up with mills or they just rub. On this basis most of us shouldn't mill ports at all!

FC3 cutters are throwaway cutters.

With small cutters, you use the best speed the machine is capable of. The mill I use only makes 2100 rpm, but it doesn't stop me using 3mm solid carbides occasionally.

What ruins small carbide cutters is sudden jerky movements , like from backlash in the table, or just not winding the table at a uniform rate. Small cutters is small feed rates. They still cut even at 1200 rpm. The other important aspect is removing the very small swarf . So having the shopvac close to the cutting area to vacuum up the stuff and a valve from an airline hooked up to be blowing a small amount of air onto the cutter is also very effective in removing the swarf from small cutters. This will extend the life of the cutter considerably. I find air to be better than using loads of coolant on small cutters.

Neil

Can you still get FC3 cutters? I couldn't find any. Thanks for the advice to blow away the swarf, I'll try to rig that up. I have always used a paint brush to brush it away but that would be a better idea. I've ordered a carbide cutter and will try it on a bit of scrap first.

Plent of FC-3 type cutters about. MSC Direct usually have them on offer for about £5 a piece, similar from Cutwell.

Edited By JasonB on 26/06/2019 08:32:07

It's rare day when I use small HSS milling cutters. Here's a 4mm carbide cutter machining a cast iron bevel gear:

There will be no problem using a carbide cutter to form ports. They have a high Young's modulus so don't tend to bend but will snap if mistreated.

The term solid carbide is incorrect. The tools are formed by sintering tungsten carbide in the form of a fine powder in a matrix of cobalt.

Andrew

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... or perhaps just 'open to interpretation'

I believe that the term came into widespread use to distinguish these cutters from those with steel shanks and brazed-on tips.

MichaelG.

I got my carbide end mill in the post today so will try it out .