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MattiJ
01-26-2019, 02:46 PM
Was fooling around with tig brazing (see the scribing caliper thread) and brazed one used DCGT insert to the end of craptastic screwdriver.
These particular inserts are really sharp out of the box and seem to sharpen easily so I wanted to see how sharp I can get the carbide insert if it is shapened to more like woodworking tool angles.

Grind to about 15 degrees, finish with well used 3000 grit diamond wheel to nearly mirror finish ("almost" "glendo" = 5 usd diamond disk on a 20 usd 3000rpm bench grinder)
Seems pretty sharp so time to test:

https://i.imgur.com/v3vj1eMl.jpg

YUP! I'm not much of hairy guy but shaves my arm without any effort (ok, took some effort not to cut myself as the tool shape is far from optimal to shaving)
Took I test cut on my beard, cuts dry with a bit of effort. Would definetely need shaving cream.

Wood?
Yes. This thing cuts dry european Beech like butter:
https://i.imgur.com/UbK1ZRdl.jpg
https://i.imgur.com/FINsD3Rl.jpg
https://i.imgur.com/FmkE8eSh.jpg

Doc Nickel
01-26-2019, 02:52 PM
No one ever said carbide couldn't be sharpened, it's that carbide doesn't stand up to USE very well when closely honed.

The nature of the beast is that tungsten carbide is effectively a powder cemented together with cobalt as a binder. between the brittleness of the TC itself and the fragility imparted by the "sintered" nature of the insert, very fine points and edges simply don't last very long.

Therefore inserts are designed around what are seemingly "blunt" edge profiles, designed to withstand cutting forces for as long as possible, to maximize tool life. That "honed" insert you just made likely won't last long even for woodworking, and for metalcutting, would likely eat itself in surprisingly short order even on aluminum.

Doc.

MattiJ
01-26-2019, 03:05 PM
That "honed" insert you just made likely won't last long even for woodworking, and for metalcutting, would likely eat itself in surprisingly short order even on aluminum.

Doc.
Was actually surprisingly durable. Even a really good carbon steel wood chisel is at the limit if sharpened to ~15 degrees and used for cutting hard endwood like that.
Wouldn't work on aluminium but nobody sharpens aluminium cutting HSS tools neither for 15 degrees :p

J Tiers
01-26-2019, 03:08 PM
+1 on Doc's post.

The books on using older carbide types recommended honing a 3 to 5 thou bevel on the cutting edge to improve tool life for just that reason. There are better carbides, but it is still particles in a matrix. The matrix does not hold tiny thin flakes as well in a sharp edge.

old mart
01-26-2019, 03:23 PM
I frequently use carbide inserts intended for aluminium for finishing steel. You can take cuts of 0.0005" easily when ordinary carbide will just make a mess. I have even used them for machining soft jaws, which is about as interrupted cut as possible. The cheap Chinese ones are the best buy, especially for the doubters to try out without breaking the bank. Even straight out of the box, they could cause a nasty little cut on the finger.

MattiJ
01-26-2019, 03:24 PM
+1 on Doc's post.

The books on using older carbide types recommended honing a 3 to 5 thou bevel on the cutting edge to improve tool life for just that reason. There are better carbides, but it is still particles in a matrix. The matrix does not hold tiny thin flakes as well in a sharp edge.

Works if you want to actually remove some material. (btw bevel is also sometimes recommended for HSS roughing tools)

These alu specific inserts come with zero bevel and seem to last pretty well on finishing cuts on a steel. Much better than any of my tooling HSS on 4140PH and yet able to take 0.02mm off from diameter without a problem (ie 5 tenths DOC)

MattiJ
01-26-2019, 03:27 PM
I frequently use carbide inserts intended for aluminium for finishing steel. You can take cuts of 0.0005" easily when ordinary carbide will just make a mess. I have even used them for machining soft jaws, which is about as interrupted cut as possible. The cheap Chinese ones are the best buy, especially for the doubters to try out without breaking the bank.

Yep, this was originally one of the ebay (fake) korloy DCGT aluminIum inserts I use mostly for steel. :cool:
They seem like a excellent alternative for HSS for light cuts.

J Tiers
01-26-2019, 04:07 PM
"For light cuts".

Yep... many things work for light cuts.

The problem with carbide is that it is not as general use as HSS... when you get doen to the niitty-gritty, you tend to find out that there is a different insert that is deigned to do just exactly what you are doing. In order to do everything with the best insert, you need drawers full of different specially made $5 to $10 per each inserts, and toolholders to fit them.

Each grade of steel has an optimal carbide, which may be blunt or sharp, round, lozenge, square or triangular. Each type aluminum ditto. And then you get into roughing, finishing, threading, with full form topping, lay down, stand up, etc etc etc. Even left and right hand threading types, and, of course, the TPI means one type per each pitch.

That's fine for the folks doing repetitive production work, but is far less help to the poor schlemazel in the basement shop.

MattiJ
01-26-2019, 04:18 PM
The problem with carbide is that it is not as general use as HSS... when you get doen to the niitty-gritty, you tend to find out that there is a different insert that is deigned to do just exactly what you are doing. In order to do everything with the best insert, you need drawers full of different specially made $5 to $10 per each inserts, and toolholders to fit them.
.
I see no problem with that and my drawers are nowhere near 3-PH lightbulb capacity. ;) 10 usd per insert... these ones I pay less than that per 10pcs box :rolleyes:
This (fake) korloy H01 grade seems to shine on insufficient speeds and very small depth of cuts on steel. (Same what I used for the M 1.4x0.2 threading exercise)

Problem is that these last too well and I don't have scrapped inserts as much as I would like :D

Anyone with used excess nanograin carbide endmills? Lemme know, I'm interested.

BCRider
01-26-2019, 04:35 PM
I frequently use carbide inserts intended for aluminium for finishing steel. You can take cuts of 0.0005" easily when ordinary carbide will just make a mess. ......

You're not the only one by a long shot. When I posted asking about carbide a year or so ago a lot of folks came back recommending exactly this for fine finish cuts on steel. And particularly when used in a holder that is angled to create some amount of back and side rake but not remove all the front and end clearance.

Still haven't got around to ordering anything but that's another story.....

There's more than a few videos on YT about re-sharpening some inserts so they can be used for general turning too.

And there's no doubt at all that carbide can be sharpened to a keen razor's edge. Table saw blades attest to that quite well.

The downside would be if a chisel like edge were used to try to lever waste out of a mortise or groove. I suspect that they might snap the edge off with such loads. Carbide is great when under compression but not forgiving to tension. That's why so many of us clumsy carbide newbies chip the ends when we try to run the carriage back out of a cut or stop the lathe and turn it backwards with the cutter still pressing into the work.

Mcgyver
01-26-2019, 04:50 PM
anyone who's ever scraped knows of course you can get carbide sharp. If it wasn't really really sharp, the 1/10,000" DOC wouldn't be possible, it would skip across the surface. However for taking very small cuts in a manual lathe, I fail to see its advantage over hss and it has obvious disadvantages such as being fragile and of course the cost.....but that's a tired old waste of time religious discussion not worth having again. We're all free to come at in our shops as we see fit.

MattiJ
01-26-2019, 05:37 PM
anyone who's ever scraped knows of course you can get carbide sharp. If it wasn't really really sharp, the 1/10,000" DOC wouldn't be possible, it would skip across the surface. However for taking very small cuts in a manual lathe, I fail to see its advantage over hss and it has obvious disadvantages such as being fragile and of course the cost.....but that's a tired old waste of time religious discussion not worth having again. We're all free to come at in our shops as we see fit.

Some old fart machinist also say that you need carbon steel scraper(old file) for mild steel but it stays enough sharp only a minute or two.. dunno it kind of sucks to scrape with anything.:p

3 Phase Lightbulb
01-26-2019, 05:37 PM
What do you think would happen if I used a 4 flute solid carbide end mill and milled away half of a large HSS end mill clamped up vertically in my vise? Do you think the interrupted cuts will chip the carbide, or maybe the HSS end mill that I'm cutting into will get chipped away? I'm wondering if solid carbide could cleanly mill a HSS end mill in half.

J Tiers
01-26-2019, 05:45 PM
Some old fart machinist also say that you need carbon steel scraper(old file) for mild steel but it stays enough sharp only a minute or two.. dunno it kind of sucks to scrape with anything.:p

Naw.... carbide works very well for scraping. And you need to get it sharp.

BUT... Scraping is usually done with a 5 deg negative rake tool, which drastically extends its sharp lifetime. We KNOW that negative rake tooling in carbide lasts a long time in relative terms.

And, I have never seen a number for the total length of cut that a carbide scraper will make before sharpening is needed. That, not time, is the real deal. And it is s tough thing to study, since the tool is used to make cuts that vary fro maybe 15 mm down to perhaps 2 or 3 mm for very precise high spot count work.

The length of cut for a carbide tool in a lathe can be more easily estimated, by diameter, rpm, and time in-cut.

This would make a very interesting study subject for someone, although I bet the carbie manufacturers already know the result.

Sparky_NY
01-26-2019, 05:52 PM
Naw.... carbide works very well for scraping. And you need to get it sharp.

BUT... Scraping is usually done with a 5 deg negative rake tool, which drastically extends its sharp lifetime. We KNOW that negative rake tooling in carbide lasts a long time in relative terms.

.

You seem confused between rake angles and edge prep. Edge prep is specified in the long part number for carbide inserts and a separate parameter beyond the angles. I'll bet you knew that even though it did not appear so.

http://www.carbidedepot.com/formulas-insert-d.htm

Mcgyver
01-26-2019, 06:31 PM
Some old fart machinist also say that you need carbon steel scraper(old file) for mild steel but it stays enough sharp only a minute or two.. dunno it kind of sucks to scrape with anything.:p

maybe your'e doing it wrong :D

The advantage of steel is its easier to sharpen or at least you need less stuff. For carbide scraping imo you pretty much need a rotary lap from a practical standpoint. I've heard tales of preferring steel in the field for that reason. However properly equipped with a lap, carbine scrapers are much better imo (and most everyone opinion i've read of those you use them). I've not notice any correlation of age or flatulence.

J Tiers
01-26-2019, 06:31 PM
For scraping, the tool does not generally use an "insert" of that type, so there is no point to mentioning part number structure.

The edge is sharp, i.e. it comes to a very tiny "edge radius", but it is also at a negative rake with regard to the "top" surface of the tool, meaning the surface that the cuttings peel off along, which is literally the top of a lathe tool, but is the "front" of a scraper, the very end of it..

strokersix
01-26-2019, 07:54 PM
What do you think would happen if I used a 4 flute solid carbide end mill and milled away half of a large HSS end mill clamped up vertically in my vise? Do you think the interrupted cuts will chip the carbide, or maybe the HSS end mill that I'm cutting into will get chipped away? I'm wondering if solid carbide could cleanly mill a HSS end mill in half.

Please post the video.

754
01-26-2019, 08:17 PM
You are better equipped than us for this, what speed will you use for 1/2 inch ?

RB211
01-26-2019, 09:40 PM
Watched a video from Sanvik on how they make inserts. This forum suffers a ton from people locked into a 1950’s to 1970’s understanding of how things are made and work. Technology has evolved, and machining has kept up with it! *Gasp*

Mcgyver
01-26-2019, 10:22 PM
Please post the video.

I do stills not videos :). This is into steel stamps, obviously not as hard as hss. I don't believe carbine would cut through an hss endmill

https://i.imgur.com/9vnOhGo.jpg

3 Phase Lightbulb
01-26-2019, 11:25 PM
I do stills not videos :). This is into steel stamps, obviously not as hard as hss. I don't believe carbine would cut through an hss endmill



That's too much drama... I'll try doing this except with a solid carbide end mill cutting through a HSS end mill.


https://www.youtube.com/watch?v=nhy9LLxnDeI

strokersix
01-26-2019, 11:34 PM
HSS twist drills have soft shanks.

thaiguzzi
01-27-2019, 12:16 AM
"For light cuts".

Yep... many things work for light cuts.

The problem with carbide is that it is not as general use as HSS... when you get doen to the niitty-gritty, you tend to find out that there is a different insert that is deigned to do just exactly what you are doing. In order to do everything with the best insert, you need drawers full of different specially made $5 to $10 per each inserts, and toolholders to fit them.

Each grade of steel has an optimal carbide, which may be blunt or sharp, round, lozenge, square or triangular. Each type aluminum ditto. And then you get into roughing, finishing, threading, with full form topping, lay down, stand up, etc etc etc. Even left and right hand threading types, and, of course, the TPI means one type per each pitch.

That's fine for the folks doing repetitive production work, but is far less help to the poor schlemazel in the basement shop.

New word for me.
I can guess, but what is a "schlemazel"?

J Tiers
01-27-2019, 01:17 AM
New word for me.
I can guess, but what is a "schlemazel"?

Well, old explanation: A Schlemiel is the guy who often spills soup on people. A screwup. A Schlemazel (or Schlemasel, Schlimazel) is the guy that people often spill soup on..... not the clumsy one, but the guy who is typically a victim, stuff goes wrong for him and it isn't really quite his fault.

MattiJ
01-27-2019, 01:21 AM
What do you think would happen if I used a 4 flute solid carbide end mill and milled away half of a large HSS end mill clamped up vertically in my vise? Do you think the interrupted cuts will chip the carbide, or maybe the HSS end mill that I'm cutting into will get chipped away? I'm wondering if solid carbide could cleanly mill a HSS end mill in half.

As we have saying around here you got fifty-sixty chances. ;)

You will probably get trough the HSS endmill but the carbide is going to get pretty much toasted in the process too. Here is a demo video of milling M2 HSS at 62RC: (with special carbide tooling)
https://youtu.be/VzfAMvnxMXY?t=84

I have milled hard HSS. On my Aciera F1! Depending on grade and hardness of the HSS your carbide cutter lifetime is going to be measured in cubic millimeters of removed material. Cleveland Mo-Max HSS lathe tool bit was particularly nasty.
Cutting forces get uncomfortably high pretty fast

MattiJ
01-27-2019, 01:52 AM
maybe your'e doing it wrong :D

The advantage of steel is its easier to sharpen or at least you need less stuff. For carbide scraping imo you pretty much need a rotary lap from a practical standpoint. I've heard tales of preferring steel in the field for that reason. However properly equipped with a lap, carbine scrapers are much better imo (and most everyone opinion i've read of those you use them). I've not notice any correlation of age or flatulence.

I use the same setup (3000 grit diamond wheel) for carbide scrapers so they are literally razor sharp. But blunt. ;)

I said I don't much like scraping mild steel with anything :p
Myself I haven't notice much difference how carbide or carbon steel scraper works other than carbon steel stays sharp for about 15 nanoseconds.

JRouche
01-27-2019, 02:37 AM
I use the same setup (3000 grit diamond wheel) for carbide scrapers so they are literally razor sharp. But blunt. ;)

I said I don't much like scraping mild steel with anything :p
Myself I haven't notice much difference how carbide or carbon steel scraper works other than carbon steel stays sharp for about 15 nanoseconds.


Umm? 3000 is pretty keen. I like it. JR

Sparky_NY
01-27-2019, 06:30 AM
HSS twist drills have soft shanks.

True, the shanks are softer. Many of the comments on the video point this out, so the guy made another video drilling through the point area of a Hansen HSS bit. https://www.youtube.com/watch?v=A8LPGGFxnNA

As for carbide cutting HSS, I will add that it is pretty common practice to mill out a broken tap with a carbide endmill in shops. The endmill suffers but does the job routinely. ( I have done it many times)

Milling hard steels, up to about Rc64 is getting more common these days, the term used is "Hard Milling", carbide endmills are used but it requires a very rigid machine/setup. Here is a explanation of the process https://www.acuity.com/acuity-focus/2016/manufacturer-focus/ask-the-manufacturing-specialist-what-is-hard-milling

(Note: Hard turning is also done in the lathe world too )

Milling a HSS endmill on a bridgport with carbide??? Going to be very challenging, if even possible, mostly due to the non rigid bridgport. I suspect the corner of the endmill will chip off quickly. A very very low feed will be needed with max rpms. A flat on the shank stands the best chance, at least its not going to be a interrupted cut !

Mcgyver
01-27-2019, 08:33 AM
I said I don't much like scraping mild steel with anything :p


agreed, I first thought you were saying scraping anything sucked, but yeah, scraping mild steel sure does.

old mart
01-27-2019, 12:50 PM
I broke a 1/4" tap in an undersize hole and drilled it out easily with a solid carbide drill.

J Tiers
01-27-2019, 02:27 PM
The carbide will drill the tap etc. but the issue often is the interrupted cut due to the shattered and rough end, possibly with more than one piece jammed in place.

Breaks a spade bit without a nanosecond hesitation, that I know.

I'd sooner sink a mounted grinding point in first to make a spot to drill. Never tried that yet.

danlb
01-27-2019, 02:42 PM
Keep in mind that there are several different grades of carbide, from very tough to very hard. Interrupted cuts are not a big deal with the right carbide, and has not been for many years. Just choose appropriately.

Dan

J Tiers
01-27-2019, 04:03 PM
Keep in mind that there are several different grades of carbide, from very tough to very hard. Interrupted cuts are not a big deal with the right carbide, and has not been for many years. Just choose appropriately.

Dan

I DO actually know that..... and already commented about it.

The "right" carbide goes directly back to my comment of needing drawers full of carbide of each shape, size, type, etc in order to have the "right" one available. Very few of us will have the "right" one available when needed for the specific thing that it is good for.

At that point, carbide becomes a problem and not a help.

I just refuse to deal with it... I have a half dozen or so varieties here, mostly by the accident of them being in the lot I bought. I have no interest in buying a couple of dozen more of them with their additional permutations of size and shape variations added to that in order to always have the "right" one on-hand.

I have lots of abrasives, and there is no issue with interrupted cuts then. No waiting days to get the job done with the "perfect matched variety" of carbide in just the form needed..

With all the specialization, carbide has become a very expensive luxury. If 3 or 4 varieties are not enough, then screw it. I am not in production here, at least not of items that need the last second of time squeezed out, so I am much less interested in the very most matched-tool-to-job situation.

Folks like you, with drawers of bins of insert carbide, drills, etc * can walk over and get the correct item. I just do not need to do that, there are other ways.

Older machines like the Logan are carbide shatterers.... flat belt machines tend to be. Comes with the territory, so I use as little ass I can get away with, in as few varieties as possible.

* Yes I am aware that you are not "3PL", and so do not have a room full of drawers with all types in there.... I was exaggerating....

MattiJ
01-27-2019, 04:24 PM
Whaddayoutalkingabout? ;)
https://i.imgur.com/s7klwbhh.jpg
https://i.imgur.com/CKwdZKNh.jpg

Those are the inserts that I haven't needed yet ;)
Some oddities etc but I paid 50 or 100 usd for the whole lot so can't complain (edit: nope, more than that as it looks like some of my CBN inserts are also included in the photo)

JRouche
01-27-2019, 05:03 PM
Keep in mind that there are several different grades of carbide, from very tough to very hard. Interrupted cuts are not a big deal with the right carbide, and has not been for many years. Just choose appropriately.

Dan

Exactly. I use carbide exclusively with my lathes. Yes, even my slow 800rpm SB 10L, flat belt. I dont destroy tips anymore. I did at first due to stalling, then I learned.

For broken taps I always go to a modified masonry bit. Works like a charm and they seem to be indestructible. JR

danlb
01-27-2019, 05:10 PM
I DO actually know that..... and already commented about it.



Jerry, it would be quite useful to keep in mind that if YOU already know that, then you were probably not the intended audience for the post. Assume it was for everyone except you. Then you don't need to get yer britches in a bunch and won't waste time posting about it.

old mart
01-27-2019, 05:15 PM
Modified masonry bits have one shortcoming, the steel shanks are too flexible. I have a set of Bosch multiconstruction bits which are sharp enough to drill steel which hss cobalt drills cannot manage. I will try sharpening some ordinary masonry bits, they don't have any use except for soft walls when you have SDS.

3 Phase Lightbulb
01-27-2019, 05:16 PM
For the solid carbide through a HSS end mill test, I'm wondering if I should use a solid carbide roughing end mill or a 2, 3,4,5 or 6 fluted end mill. I'll be using my CNC bridgeport so I think the precision ball screws and a controlled feed rate will probably help keep the chatter down. Maybe I'll try it out tomorrow.

old mart
01-27-2019, 05:25 PM
I would do some tests first. A centre cutting four flute works for me, although a drill would be my first choice.

J Tiers
01-27-2019, 06:42 PM
Matti is well set up with inserts, but I'd bet that when you need some special type it will not be in that lot. Carbide selection seems to have gotten almost to the point of offering the equivalent of "certified telephone sanitizers".

Masonry bits are a reasonable alternative in some cases, but they were never really intended to be sharpened, and it shows. I have drilled hard chuck jaws with sharpened masonry bits, but they seem to break down fairly fast to their usual somewhat blunt stable state. I doubt they use any particularly special carbide, except for the hammer drill ones. THOSE will take almost any abuse, but are limited in sizes available.


Jerry, it would be quite useful to keep in mind that if YOU already know that, then you were probably not the intended audience for the post. Assume it was for everyone except you. Then you don't need to get yer britches in a bunch and won't waste time posting about it.

Your concern and worry about my convenience is noted, but unnecessary. Besides your note about interrupted cuts gives you away......

danlb
01-27-2019, 06:51 PM
Your concern and worry about my convenience is noted, but unnecessary.

Really, I don't give a rats patoot about your convenience. As the saying goes... Not everything is about you. But I do care about others and I've been told that the sniping between you and I is irritating others.

MattiJ
01-28-2019, 04:41 AM
Matti is well set up with inserts, but I'd bet that when you need some special type it will not be in that lot. Carbide selection seems to have gotten almost to the point of offering the equivalent of "certified telephone sanitizers".

Home shop guy doesn't need to get carried away with carbide grades, just like you don't need to care much if you are using Rex 95, REX AAA, T4, M2, Mo-Max or M42 HSS in the home shop...
You might lose some "productivity" or insert lifetime if you are using steel grade for stainless or alu insert for titanium but so what...

Interrupted cut gets mentioned a lot with carbide.. mostly non-issue in lathe work if the lathe is anything better than smallest stock 7x14 noodle. Almost any of the current carbide grades handle interrupted cuts beyond your wildest dreams. Problems usually start to show up at hardness levels where HSS is already feeling miserable.
Try parting 10mm Bondhus hex key with HSS and tell how does it go with HSS. ;) (about HRC 58-60 high carbon Cr-V steel)

3 Phase Lightbulb
01-28-2019, 08:47 AM
The carbide will drill the tap etc. but the issue often is the interrupted cut....

I DO actually know that..... and already commented about it. :p:p:p:p

old mart
01-28-2019, 12:37 PM
One slight downside of having lots of solid carbide which is not in the original packing is the lottery of whether the cutter is the best for the job. I destroyed a brand new Kennametal solid carbide drill in steel, with hindsight, the relief angles were more for aluminium. The 1/4" tap which I broke was dead tight in steel and using a solid carbide drill intended for hardened steel worked partly because of it's stiffness. My feed rate was very slow.

stefang
01-28-2019, 02:44 PM
Look at a carbide single flute endmill for machining aluminium - Superfine finshed cutting edge and very small cutting angle. And they last looooong.

The everlasting myth of carbide that cant get a sharpe edge. There are many factors to this.

A sharp edge is simple, as stated before by other, just look at a scraper blade.
Acute Angles are a bit more of a problem, but they are also with Hss.


However for taking very small cuts in a manual lathe, I fail to see its advantage over hss and it has obvious disadvantages such as being fragile and of course the cost

Break a good quality carbide endmill and you have a source for nice, high quality micrograin carbide ;)

I stoped grinding form tools out of Hss for the most part, almost everything I do is carbide now. I find it easier/faster to grind, it keeps the edge in tough materials longer and its stiffer (relevant when the tool hangs out).

Hss is also very fragile if you bump it against a hard surface, done that enough times. Dont bump your tools.


For the solid carbide through a HSS end mill test, I'm wondering if I should use a solid carbide roughing end mill or a 2, 3,4,5 or 6 fluted end mill. I'll be using my CNC bridgeport so I think the precision ball screws and a controlled feed rate will probably help keep the chatter down. Maybe I'll try it out tomorrow.

In a pinch, when I make parts that need to be hardened, I use a piece of a HSS blank, grind/mill it to shape. Drilling is also possible, either with a good carbide drill or with a ball-endmill. Countersinking with a 4-flute carbide chamfermill.

Thats a custom key for a Schaublin70 support out of a Hss Blank:
http://gtwr.de/div/pro_schaublin70_anschlag_006.jpg

Drilling a HssCo10 blank to become an alignment-guide for the wheelhead of my T&C grinder:
http://gtwr.de/div/knuth_werkzeugschleifmaschine_043.jpg

In Place:
http://gtwr.de/div/knuth_werkzeugschleifmaschine_045.jpg

Stefan

MattiJ
01-28-2019, 05:13 PM
Stefan, same here, I also grind speciality tooling and one-offs e more often from carbide. Endmills and used inserts are free. And if you know someone in pcb business the printed circuit board drills are nice source of material.