Insert facemilsl, correct use on hardened Steel.

[ChrisBParticipant @chrisb35596]

I have used a banggood 50mm facemill with 4 APMT inserts to shave 4mm off a hardened lathe insert holder. As you say, lots of sparks and hot chips flying everywhere, but the finish was surprisingly very good. I did use branded inserts tho, as the ones supplied with the facemill were not so good for steel.

[Tony Pratt 1Participant @tonypratt1]

Compare the mass of a chip to the mass of a toolholder, guess why the chips get hot but the holder doesn't.

Tony

[Ketan SwaliParticipant @ketanswali79440]

Posted by JasonB on 08/05/2020 19:40:11:

Job's a good un, that's how Ketan likes to use them too!

Indeed Steve

In my defence, I was only following Andrews advice… be it sheepishly.

Ketan at ARC.

[SteviegtrParticipant @steviegtr]

Well that is a surprise. I was expecting a hail of abusive comments about how useless I am. Ok I am anyway. But a great result apart from I set a piece of tissue on fire that was sat on the table. Anyway I did a gopro video of doing it & will compare it to the one I did yesterday, with the different inserts in. Seems these are Iscar, carbide Tialon coated or something like that. They stood up well so just another 3 holders to go.

Steve.

[SteviegtrParticipant @steviegtr]

I previously on another thread asked about using a facemill on hard steel. I had tried it & got a lot of sparks from them. I stopped the work immediately & sought advice.

The general opinion was that something was wrong. It was also suggested that I had the wrong inserts for the job. So I ordered some inserts which were specified for Cast iron & general hard metals. I fitted these & tried again.

The results were even more sparks akin to bonfire night.

I spoke to a friend who does a lot of car repair work & uses his milling machine a lot. I sent him a short video of what was happening & he said no that is fine. Hard steel can be like that. He remarked that say EN1 mild would not do that but a lot of hardened steel & some types of cast iron do too.

I also tried a Chinese one which was a 4 insert version. This did exactly the same , but the finish was a bit rougher. When removed I could see one of the inserts was just shy of the work. But other than that it worked fine. At something like £23 complete with 10 inserts & the Arbor it worked admirably.

The 6 insert one I have is quite an expensive used item & the inserts alone were £33 per 10. Then this was mounted on a Chinese arbor that was very accurate. So I have carried on using the cutter & the results are on a video should anyone care to have a look.

By all means give me your opinion. But the video speaks for itself. My machine is a Tom Senior light vertical with 1/2hp & MT2 spindle so I did not push my luck too much in the way of depth of cut & travel speed..

Making some sparks

Steve.

Edited By JasonB on 13/05/2020 10:01:03

[Thor 🇳🇴Participant @thor]

Hi Steve,

You are not the only one that has experienced sparks when milling hard steel using carbide tipped tools. My experience is that carbide tipped tools work best at a high speed.

Thor

Edited By JasonB on 13/05/2020 10:01:24

[not done it yetParticipant @notdoneityet]

Looks like someone bought cheap from bang good or other really cheap site, if they don’t fit properly.🙂 No recourse for complaint, through ebay or paypal, for those purchases.🙂

They might give back the cost if you posted them back for their appraisal.🙂. Otherwise they might offer you ten per cent off. It’s their way of getting something for their rejects instead of scrapping them.

Edited By JasonB on 13/05/2020 10:01:49

[Martin ConnellyParticipant @martinconnelly55370]

Grinding wheels are ceramic. The tool cutter bits are ceramic. Surely using a ceramic insert cutter on hard steel is akin to grinding hard steel with a bench grinder. We should expect sparks rather than be surprised by them. The mill is just a well controlled way of achieving the metal removal (and a good finish) compared to off hand grinding. Good job Steve.

Martin C

[Ketan SwaliParticipant @ketanswali79440]

Posted by Steviegtr on 13/05/2020 01:53:36:

I previously on another thread asked about using a facemill on hard steel. I had tried it & got a lot of sparks from them. I stopped the work immediately & sought advice.

The general opinion was that something was wrong.

Steve.

I am a little bit confused by what you are saying Steve. Reading through this thread from the beginning, I can't see anyone saying that if there are sparks flying … that something was wrong. All I read was general advice based on what you posted.

Ketan at ARC

Edited By Ketan Swali on 13/05/2020 11:42:44

[larry phelan 1Participant @larryphelan1]

Why does anyone with light machines bother to buy expensive cutters and inserts, when there is no way they can provide the ideal conditions to exploit them ? Unless your time is MONEY [and if it is, you would have better machines anyway ] ,you are unlikely to gain very much. As another Member said, these inserts/cutters ect are intended for machines around 20 ton Wt with 20/30 HP motors nailed onto them, talking cuts of around 10mm, not exactly backyard workshop style !

[Ketan SwaliParticipant @ketanswali79440]

Larry,

It was part of his bargain eBay purchase, see link to thread… which worked out for him…. after he got a lot of advice on this thread. His last response about general opinion from the collective is a little confusing. To understand, one needs to read this thread from the beginning.

Ketan at ARC.

Edited By Ketan Swali on 13/05/2020 12:14:38

[JasonBModerator @jasonb]

Posted by larry phelan 1 on 13/05/2020 12:04:25:

Why does anyone with light machines bother to buy expensive cutters and inserts, when there is no way they can provide the ideal conditions to exploit them ? Unless your time is MONEY [and if it is, you would have better machines anyway ] ,you are unlikely to gain very much. As another Member said, these inserts/cutters ect are intended for machines around 20 ton Wt with 20/30 HP motors nailed onto them, talking cuts of around 10mm, not exactly backyard workshop style !

I think on of the biggest advantages is that you can use them on iron castings that may well have hard spots or chilled areas. Go at them with HSS and it will blunt the cutter in seconds. Keep using a solid carbide cutter for facing cuts and all you are going to do is blunt the end before you have use the rest. In both cases four inserts at say £3 each will be cheaper than a decent 12mm HSS cutter and definately less than a 12mm solid carbide particularly when you get two or three new edges depending on the shape of the insert.

With the right inserts they will work on most things and again stop you wearing just the end of a solid cutter so work out quite an economical way to machine flat areas, or in the case of the 90deg shell mills vertical faces too.

Don't really agree with your comments about big machines and 10mm cuts. Plenty of commercial CNC use on smaller machines will use these cutters to skim maybe 1mm off the top surface of the oversize stock. They don't want to waste machine time doing 6 or 8 stepover passes where one pass with a facemill will do, as you said "time is monet".

Then there are those that can't grind a flycutter bit so the facemill provides a useful alternative for them to face large areas.

 

Edited By JasonB on 13/05/2020 13:28:08

[Grindstone CowboyParticipant @grindstonecowboy]

Just as an aside, but still relevant, here is a bit of video from Eccentric Engineering showing sparks from carbide tooling that coincidentally popped up on my Facebook feed.

In case the write-up that accompanies it fails to come with the video, it reads: " Sparkly! “>🤩
Milling the two sides that had previously been flame cut was a bit of a light show “>😁
It was quite a bit tougher to get through too going by the marks left by the face mill.
Once through the surface the sparks stopped on the subsequent passes. "

Hope this works, not tried a video before!

**LINK**

[SteviegtrParticipant @steviegtr]

In response to why used such a cutter on a small mill. I did try a HSS 3/8" ? from memory cutter. This did not touch the steel. I then tried a HSS flycutter of which it just took the edge off straight away. I have some good quality carbide 3 & 4 flute end & slot mills of various sizes. I have not tried them yet.

I was just giving the 50mm one a try seen as I already had one. Apart from the sparks galore the results were good. I did try taking deeper cuts, but felt it was maybe too much for the machine. That is just my thought, the machine may take deeper cuts but the last thing I want is a great jam up & an eye out. Time is not important so going slow is no problem. From comments given I may try running at a higher speed. Heat does not seem to be an issue so I higher speed maybe the answer. All in all I was happy that the cutter actually worked with only 1/2hp to drive it.

The other one I tried but not shown in the video was a ebay special. It was very cheap & complete. It did perform well but had 1 of it's 4 inserts just slightly missing the work. I did buy that one new & regret not buying from a reputable seller like Arc etc. I have a lot of alloy to work on for another little project & I am sure it will be ok on that.

Steve.

[SteviegtrParticipant @steviegtr]

Posted by Ketan Swali on 13/05/2020 11:42:09:

Posted by Steviegtr on 13/05/2020 01:53:36:

I previously on another thread asked about using a facemill on hard steel. I had tried it & got a lot of sparks from them. I stopped the work immediately & sought advice.

The general opinion was that something was wrong.

Steve.

I am a little bit confused by what you are saying Steve. Reading through this thread from the beginning, I can't see anyone saying that if there are sparks flying … that something was wrong. All I read was general advice based on what you posted.

Ketan at ARC

Edited By Ketan Swali on 13/05/2020 11:42:44

Posted by not done it yet on 08/05/2020 07:51:29:

No, it is not “OK” for lots of sparking to occur.

[Ketan SwaliParticipant @ketanswali79440]

Posted by Steviegtr on 13/05/2020 14:55:39:

Posted by Ketan Swali on 13/05/2020 11:42:09:

Posted by Steviegtr on 13/05/2020 01:53:36:

I previously on another thread asked about using a facemill on hard steel. I had tried it & got a lot of sparks from them. I stopped the work immediately & sought advice.

The general opinion was that something was wrong.

Steve.

I am a little bit confused by what you are saying Steve. Reading through this thread from the beginning, I can't see anyone saying that if there are sparks flying … that something was wrong. All I read was general advice based on what you posted.

Ketan at ARC

Edited By Ketan Swali on 13/05/2020 11:42:44

Posted by not done it yet on 08/05/2020 07:51:29:

No, it is not “OK” for lots of sparking to occur.

Apologies. Got it, and thanks for clarifying the confusion.

Ketan at ARC

[Ketan SwaliParticipant @ketanswali79440]

Posted by Steviegtr on 13/05/2020 14:40:55:I did buy that one new & regret not buying from a reputable seller like Arc etc. I have a lot of alloy to work on for another little project & I am sure it will be ok on that.

Steve.

Nothing to regret Steve. We all learn something new everyday, and everyone has their own experience with their purchase.

Ketan at ARC.

[SteviegtrParticipant @steviegtr]

Ha ha. No problem. Since watching your video, sparks are no longer a concern. I did set fire to a tissue sat on the tray though.

Steve.

[Ketan SwaliParticipant @ketanswali79440]

I think Jason just posted a screenshot of my video. I do not think he put up the whole video, which I would not like uploaded, because I was potentially abusing the tool and the machine to test out Andrews theories. It was me playing with the shell mill, milling away some stainless steel I had acquired for testing from the late JS.

Ketan at ARC

[SillyOldDufferModerator @sillyoldduffer]

Posted by Steviegtr on 13/05/2020 01:53:36:

I previously on another thread asked about using a facemill on hard steel. I had tried it & got a lot of sparks from them.

…

I spoke to a friend who does a lot of car repair work & uses his milling machine a lot. I sent him a short video of what was happening & he said no that is fine. Hard steel can be like that. He remarked that say EN1 mild would not do that but a lot of hardened steel & some types of cast iron do too.

…

By all means give me your opinion. But the video speaks for itself. My machine is a Tom Senior light vertical with 1/2hp & MT2 spindle so I did not push my luck too much in the way of depth of cut & travel speed..

Making some sparks

Steve.

Entertaining video, and turns out Steve sounds just like my Brother-in-Law!

Anyway, I think the sparks are because the inserts are rubbing as much as cutting. The polished look of the job suggests rubbing too.

Steve's Tom Senior has a ½HP motor, which is very much on the small side for driving a whopping big 5 toothed cutter through hardened steel. The depth of cut and feed rate available to Steve are well below optimum. Lack of grunt obliges a shallow cut producing small, fine swarf at high temperature. Most of the firework display is due to swarf burning, not the cutting operation. The swarf is catching fire.

If the depth of cut were increased to 1 or 2mm then the improved cut to rub ratio would make less frictional heat. Also, bigger chips can absorb more heat without their temperature sky-rocketing. And their smaller surface area to mass ratio makes them less likely to catch fire or keep burning.

Steve mentions he thinks his inserts might be going blunt. Worth checking them with an eye-glass. It's possible; if most of the mill's motor power is converted to bright red heat due to rubbing the inserts narrow edges, then the carbide may well suffer. Again, lack of power and speed are relevant. Carbide inserts aren't designed to scrape metal off a surface, rather the point is meant to penetrate deep under the surface and then wedge chips off. Working properly, the delicate edge of an insert isn't in contact with the job at all. As with getting a speedboat to hydroplane though, quite a lot of power is needed to start the process properly, especially with the blunt inserts recommended for steel.

For this job: bigger motor (not a good idea), much bigger mill (yes please!), or sharp inserts and fewer teeth on the face-mill. Be interesting to try a fly-cutter with a single carbide insert and a deeper cut. I think the job would take about the same time, leave the insert in good condition, produce bigger chips, a milled finish, and less fireworks. It's how best to apply that ½HP to this particular job. Probably not a real problem for most work: the mill and cutter might perform well-enough on mild-steel, and the pair are only struggling because the tool-holder is made of something extra tough!

Dave

[JasonBModerator @jasonb]

Posted by SillyOldDuffer on 13/05/2020 15:42:38:

Steve's Tom Senior has a ½HP motor, which is very much on the small side for driving a whopping big 5 toothed cutter through hardened steel. The depth of cut and feed rate available to Steve are well below optimum. Lack of grunt obliges a shallow cut producing small, fine swarf at high temperature. Most of the firework display is due to swarf burning, not the cutting operation. The swarf is catching fire.

If the depth of cut were increased to 1 or 2mm then the improved cut to rub ratio would make less frictional heat. Also, bigger chips can absorb more heat without their temperature sky-rocketing. And their smaller surface area to mass ratio makes them less likely to catch fire or keep burning.

Dave one moment you say Steve's machine does not have much power and then you suggest he takes off upto thirteen times as much metal off in a pass, I doubt it would do that in mild steel let alone hardened, I know 2mm on a similar width of mild steel would have the X3 popping it's trip and the SX2.7 would not be happy doing half that. What type of cuts can you do on yours with a similar facemill?

[SillyOldDufferModerator @sillyoldduffer]

Posted by JasonB on 13/05/2020 16:23:03:

Posted by SillyOldDuffer on 13/05/2020 15:42:38:

Steve's Tom Senior has a ½HP motor, which is very much on the small side for driving a whopping big 5 toothed cutter through hardened steel. The depth of cut and feed rate available to Steve are well below optimum. Lack of grunt obliges a shallow cut producing small, fine swarf at high temperature. Most of the firework display is due to swarf burning, not the cutting operation. The swarf is catching fire.

If the depth of cut were increased to 1 or 2mm then the improved cut to rub ratio would make less frictional heat. Also, bigger chips can absorb more heat without their temperature sky-rocketing. And their smaller surface area to mass ratio makes them less likely to catch fire or keep burning.

Dave one moment you say Steve's machine does not have much power and then you suggest he takes off upto thirteen times as much metal off in a pass, I doubt it would do that in mild steel let alone hardened, I know 2mm on a similar width of mild steel would have the X3 popping it's trip and the SX2.7 would not be happy doing half that. What type of cuts can you do on yours with a similar facemill?

I put it badly Jason, I'm explaining the fireworks, not suggesting they can be fixed by hammering the Tom Senior. I meant if Steve had a machine powerful enough to take heavy cuts, then he could go deep and hard without fireworks. I'm suggesting his relatively small machine scrapes hot thin swarf that catches fire, whereas big chips produced by a more powerful machine driving the same face-mill into the tool-holder wouldn't burn. Smoke and blue, but less likely to flame.

I think the combination of carbide face-mill and that steel is too much for the small motor, and Steve might do better with a fly-cutter. My 1100W WM18 wouldn't take 2mm cuts in hardened steel either!

Dave

[old martParticipant @oldmart]

I use a 50mm diameter Ceratizit shell mill with 5 round 12 mm inserts for machining harder types of steel. Not really hard, but the shanks of indexable lathe tools. The life expectancy of the inserts is about one tool reduced from 20mm to 17.53mm, the centre height of the lathe. This is not as bad as it seems, as the round inserts are indexable in 8 positions in the holder. The Ceratizit is designed for die machining for stainless steel, so the insert grade is not ideal, but I have amassed a good quantity at an average of £2 per insert.

It is easy to see when the inserts are going off, the sparks increase and the workpiece heats up. New edges put very little heat into the workpiece.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by SillyOldDuffer on 13/05/2020 16:47:14:

[…]

I think the combination of carbide face-mill and that steel is too much for the small motor, and Steve might do better with a fly-cutter.

.

Indeed he might … but:

With a six-insert face-mill, it would seem simple enough to try using three, or two inserts … maintaining balance but reducing load on the machine.

MichaelG.

[SteviegtrParticipant @steviegtr]

Posted by Michael Gilligan on 13/05/2020 17:34:24:

Posted by SillyOldDuffer on 13/05/2020 16:47:14:

[…]

I think the combination of carbide face-mill and that steel is too much for the small motor, and Steve might do better with a fly-cutter.

.

Indeed he might … but:

With a six-insert face-mill, it would seem simple enough to try using three, or two inserts … maintaining balance but reducing load on the machine.

MichaelG.

You are not the 1st to say that, so I will give it a try maybe tomorrow & report back.

Steve.

[Author]

Posts