Drilling "Caldie" - Need help - Or S7...

I have a customer that is drilling some material called "Caldie" from Boehler Uddeholm.

UDDEHOLM CALDIE | Bohler Uddeholm

I spoke with Boehler about this material several weeks ago, and was told that it's "close to S7".

.7% Carbon
.2% Silicon
.5% Manganese
5.% Chrome
2.3% Molybdenum
.5% Vanadium

Harden-able to 60hrc. Supplied in annealed (215hb) condition.

The customer insists that it's like cutting a "tougher D2" however, their drilling chips don't look like that of D2. In my experience, D2 will produce chips from drilling much like brass - very short, fragmented & broken. The customer's chips in the Cal-Die material are short, and nicely formed & broken, as typical of a H.P. carbide drill in alloy steels.

The spec sheet for this "Cal-Die" material also looks very similar to S7 in chemical composition, and also in regards to hardness vs. toughness characteristics. Not to mention D2 typically has 1.5% carbon & 12-12.5% chrome, and this Caldie material is only 5% chrome.




My customer has to drill several holes 22mm diameter, up to say 6"/150mm in length. Machine is a DMG-Mori NVX5100, less than 1 year old. 15k spindle, 40-taper, with TSC. For shorter holes, they're able to use a short indexable drill, but a 5xD indexable drill will not stabilize on entry, produces a terrible hole quality, and chips the inserts after one hole. (Presumably after initial contact/entry...) The have tried spotting with a matching 2-3xD indexable drill, and milling a counterbore with an endmill, which they claim makes no difference.

They're hesitant to try a Seco crown-loc drill, because of fears over the connection... Lately, they've tried a Guhring replaceable-tip drill from my competitor. They're running that drill slow (350rpm for carbide) and experienced a few holes before chipping/cracking the insert and slightly deforming the cutter body.





Emphasis is on security against broken drills/tips. I'm getting ready to recommend an Allied spade-drill with cobalt inserts because of the toughness of the cobalt insert. This is right in that awkward size/depth range, where indexable's won't work because of the length, and it's too big in diameter for solid carbide drills. So replaceable-tip drills seem to be the only way to go.




I'm looking for people who have worked with this Caldie material, or even S7 at this point.

What kind of replaceable-tip drills have you had success with drilling these materials?

Just FYI - I'm a distributor for Walter, Seco, Allied, Kyocera, OSG, and Dormer. So any direct experience with these lines would be an even bigger plus...

When I drill tougher tool steels like H13 S7 3V D2 I run 110sfm and .004ishh feed per rev and peck about .1 or so depending on my drill dia and set up. Are you pre drilling the hole?

Sorry I have no experience with that particular steel.

"Supplied in annealed (215hb, condition." What does this mean as far as hardness is concerned?

I like the guy above me drill tool steel (CPM, Viscount/V-44, Anviloy) at around 75 to 100sfm at .004" to .005" pre/rev pecking every .1 using a cobalt twist drill. But the steel isn't hard. It's pretty tough but not hard it's RC46ish.

The holes I'm drilling are also deep perk or water line holes and size isn't as much as an issue as just getting to the bottom. Instead of using a long drill with long flutes that I think like to grab I make my own. I thread the end of a cobalt drill then drill and tap a piece viscount drill rod the screw them together and use that.

I hand grind the drill off center to open the hole up to increase my chances of making it to the bottom as the drill wears. Sometimes stopping to sharpen the drill a couple times if need be. It's a slow BS process but that's what I do.

The spade drills will do a good job but I never could get the depth.

Brent

http://www.practicalmachinist.com/v...length-drills-309685-post2628023/#post2628023

I have drilled some real nasty steels pretty deep with cobalt running real slow and frequent pecks.

215hb doesn't even register on the Rockwell-C scale. My best guess is 15-18hrc. However, they have some parts coming in the same material that will be "pre-heat treated..." That could mean anything, although they mentioned today (verbally) that the blocks should be 40hrc...

Size (diameter) is not important. These are counterbores for SHCS. But the are having trouble drilling holes even beyond 3xD. Quantites aren't huge, but enough to make using HSS twist-drills a pain, and for all practical purposes unreasonable.


At this point, I'm leaning toward an Allied Gen-2 spade drill, with their super-cobalt inserts for toughness. A second choice (carbide) is a Dormer "Hydra" drill, for it's connection. It's a full-tip insert, with a serrated connection and 2 screws, so it should be pretty robust.

I'm still open to feedback. Thanks.

Holy Hell, you're supposed to be the guy with all the answers. J/K

This is against what is acceptable procedure these days. I would use 3 drills. First, a stub length 10mm. Second, a full depth 10 mm. And lastly Drill to size and depth. (don' forget the center drill) All 3 TSC, with standard feeds and speeds for tough gummy material. 220 bhn is like 11 Rockwell.

So this procedure is not one that I would normally recommend, as tool tech. is so good these days. But it sounds like you/they need to get the job done right, and quit fucking around. I like the Gen2's, but for this application I would still want a pilot all the way to depth.

FWIW, I think someone is running an Indexable like a bunch of Nancies. I would be willing to place a Dollar amount bet that I could get those holes right with a 5x diameter Insert Drill. No pilot, No peck, No nothing. Unfortunately I cannot speak to the Brands you listed for Drilling. Oldies but goodies;

Iscar DR may be the most dependable all around Drill I've ever used.
ISCAR Cutting Tools - Metal Working Tools - DR-5D-N

Kennametal DFT is pretty much a battering ram.
Drill Fix • DFT

Jashley73 said:

At this point, I'm leaning toward an Allied Gen-2 spade drill, with their super-cobalt inserts for toughness.

Click to expand...

Allied's guru has been active on PM, and not all that long ago. Saved ME from buying spades my AB5/S couldn't use effectively even if I had added a HP coolant system.

Contact them directly?

Oh wait.. new info? Didn't see the bit about your being a "distributor" already.

yardbird said:

"Supplied in annealed (215hb, condition." What does this mean as far as hardness is concerned?

Click to expand...

Jashley73 said:

215hb doesn't even register on the Rockwell-C scale. My best guess is 15-18hrc.

Click to expand...

Correct, 215 Brinell is about 18Rc.

Litlerob1 - They're using Seco Perfomax indexable drills. 3xD and 4xD.

Keep in mind, on a mill you add 3-4” Gage length with the Weldon holder... All together, that becomes a tool assembly about 8” long, on a 40 taper. Should be fine with a true center-point drill. Getting sketchy on an indexable, with no true center.

We will be discussing some short-weldon holders, which are about an inch shorter than normal.


All of this just doesn't compute for me though. It's not a crazy alloy content. The material isn't "hard." So it's not like we're trying to cut Inconel 600. So it doesn't make sense to me why this relatively soft, low/medium alloy STEEL is so difficult to drill.

litlerob1 said:

FWIW, I think someone is running an Indexable like a bunch of Nancies. I would be willing to place a Dollar amount bet that I could get those holes right with a 5x diameter Insert Drill. No pilot, No peck, No nothing.

Click to expand...

Jashley73 said:

Litlerob1 - They're using Seco Perfomax indexable drills. 3xD and 4xD.

Click to expand...

I'm with Rob, pretty sure I could make an insert drill work if I had that job on a machine here.

However at 5xD you need a drill with good centering/tracking characteristics, which all of the square insert drills are really quite poor at.

Lozenge insert drills (Mitsubishi TAF, Tungaloy TDX etc.) are very good in gummy materials at long LxD ratios.

"I'm looking for people who have worked with this Caldie material, or even S7 at this point."

I Have.

"What kind of replaceable-tip drills have you had success with drilling these materials?""

In 16-22mm I have used Iscar Cam Drills.
They work great.
19mm runs at 1787 RPM @ 18 IPM.Chip break the drill cycle.
It was important to anticipate failure because when they fail it is almost always on entry. You end up with a mushroom.

JCarroll said:

"I'm looking for people who have worked with this Caldie material, or even S7 at this point."

I Have.

Click to expand...

Caldie or S7? If both, do they cut quite similar, or is there a marked difference? Also, why so much trouble with the entry? That's consistent with what they're experiencing, but I'm puzzled why.

Thank you for the feedback.

I work with tool steels all the time and this is a head scratcher, it leads me to believe that it's not anything specific to the material. Annealed S7 or Caldie isn't a particularly difficult material. The only thought I have is that tools steels hate heat, if the SFM is too high or coolant flow not adequate you could be hardening the material especially at the outside of the hole.

What do the chips look like, they should be bright, no discoloration. Hot tool steel is hell on tools.

Jashley73 said:

All of this just doesn't compute for me though.

Click to expand...

If things are to "compute", what do we know about what coolant, if any, is being used?

Characteristic to all the "Allied" hole-bragging videos I have seen is a serious flow of high-pressure coolant.

"Modern" tooling lets us get away with working so VERY many things "dry" it may have become a bad habit?

I've used those Allied replaceable cobalt tip drills in prehard H13 with good results.

Coolant is Blaser Blasocut 2000. They have thru-spindle coolant on the machine. Pressure unknown - probably the standard 100psi or whatever is "standard" for the machine. Flow is limited by the coolant holes in the drill of course. I've already told them to up the concentration from their normal 8% to 12-14%.

I should say however that I think the coolant is irrelevant at this point. They haven't "worn" a single drill so far. Failure mode has always been some kind of chipping/fracturing/breaking...

I'm of the opinion that doesn't happen mid-hole on solid material. Any kind of mechanical damage should occur on entry/exit.

Next time I visit, I'll check run-out of the holder & drill-tip. I'll also try to load a tool in the spindle, and push against it, observing deflection with an indicator, and compare to their other machines. I'm not sure what else to "check" short of trying a HSS/Cobalt/Allied drill...

Jashley73 said:

Coolant is Blaser Blasocut 2000. They have thru-spindle coolant on the machine. Pressure unknown - probably the standard 100psi or whatever is "standard" for the machine. Flow is limited by the coolant holes in the drill of course. I've already told them to up the concentration from their normal 8% to 12-14%.

I should say however that I think the coolant is irrelevant at this point. They haven't "worn" a single drill so far. Failure mode has always been some kind of chipping/fracturing/breaking...

I'm of the opinion that doesn't happen mid-hole on solid material. Any kind of mechanical damage should occur on entry/exit.

Next time I visit, I'll check run-out of the holder & drill-tip. I'll also try to load a tool in the spindle, and push against it, observing deflection with an indicator, and compare to their other machines. I'm not sure what else to "check" short of trying a HSS/Cobalt/Allied drill...

Click to expand...

Has the aroma of "work hardening" to my nose. Remote though it may be...

Jashley73 said:

I have a customer that is drilling some material called "Caldie" from Boehler Uddeholm.

UDDEHOLM CALDIE | Bohler Uddeholm

I spoke with Boehler about this material several weeks ago, and was told that it's "close to S7".

.7% Carbon
.2% Silicon
.5% Manganese
5.% Chrome
2.3% Molybdenum
.5% Vanadium

Harden-able to 60hrc. Supplied in annealed (215hb) condition.

The customer insists that it's like cutting a "tougher D2" however, their drilling chips don't look like that of D2. In my experience, D2 will produce chips from drilling much like brass - very short, fragmented & broken. The customer's chips in the Cal-Die material are short, and nicely formed & broken, as typical of a H.P. carbide drill in alloy steels.

The spec sheet for this "Cal-Die" material also looks very similar to S7 in chemical composition, and also in regards to hardness vs. toughness characteristics. Not to mention D2 typically has 1.5% carbon & 12-12.5% chrome, and this Caldie material is only 5% chrome.




My customer has to drill several holes 22mm diameter, up to say 6"/150mm in length. Machine is a DMG-Mori NVX5100, less than 1 year old. 15k spindle, 40-taper, with TSC. For shorter holes, they're able to use a short indexable drill, but a 5xD indexable drill will not stabilize on entry, produces a terrible hole quality, and chips the inserts after one hole. (Presumably after initial contact/entry...) The have tried spotting with a matching 2-3xD indexable drill, and milling a counterbore with an endmill, which they claim makes no difference.

They're hesitant to try a Seco crown-loc drill, because of fears over the connection... Lately, they've tried a Guhring replaceable-tip drill from my competitor. They're running that drill slow (350rpm for carbide) and experienced a few holes before chipping/cracking the insert and slightly deforming the cutter body.





Emphasis is on security against broken drills/tips. I'm getting ready to recommend an Allied spade-drill with cobalt inserts because of the toughness of the cobalt insert. This is right in that awkward size/depth range, where indexable's won't work because of the length, and it's too big in diameter for solid carbide drills. So replaceable-tip drills seem to be the only way to go.




I'm looking for people who have worked with this Caldie material, or even S7 at this point.

What kind of replaceable-tip drills have you had success with drilling these materials?

Just FYI - I'm a distributor for Walter, Seco, Allied, Kyocera, OSG, and Dormer. So any direct experience with these lines would be an even bigger plus...

Click to expand...

Monarchist beat me too it... And others...

Time is limited today (been goofing off too much lately ;-) ).

I read the first PDF on the U-Caldie link. Have to find time to read the other two pdfs

The key aspect of that material is how incredibly resilient it is to surface cracking when hardened (in all manner of ways)... AND it has incredible compressive strength properties. Its almost like its designed to form a super strong "Skin" that is also very tough and is super resistant to cracking... I.e. very difficult to make a chip from.

The other thing that caught my eye was how easy it is to "Flame Harden" 58-62 HRC to depth of about 3 mm (with a pretty lame oxyacetelene torch... ). My father was originally trained as a hand engraver (in Germany) and he taught me engraving as a teenager (for a few years), so it IS actually very easy to harden a tool steel with a low temperature flame... and relatively quickly and same with "Spring Steels"/when blued.

Also on the PDF under TIG welding 54-62 HRC ...


The machine is a DMG Mori NVX 5100 is a very powerful machine, box ways and tons and tons of torque... Probably too much for a 40 taper anyway.

So I think your (@jashley) basic hunch of how to "Sneak" into the surface of the material and "Follow" through in a different way IN-CUT seems to "feel" right. OR plunge very dramatically and duck (so the material does not have time to build up heat and almost work harden in cut.) So keeping the cutting surface as cool as possible would be critical, as that's a really deep cut. Pecking in the wrong way could cause severe work hardening.

In the case of the NVX I could imagine a situation where the material hardens by friction and heat build up as the machine does not react to the material and it seems the material is doing it's best to "Bite back".



I really wonder how this would go in a fairly meaty manual mill, so you can almost "Feel" the reaction forces and the "FEEL" one or two ways to make it into the material (different roads to Rome).

In some ways also your hunch for a less perfect "Connection" might also be the ticket as the connection might give just at the surface by the right amount at exactly the right instant.


I'm just saying I think your intuitions kinda chime with mine a bit @jashley... (Even though I may be smoking crack).

Personally I think the machine is the problem as it's too unyielding and how its being used. Or like what LittleRob is saying they are being p*ssies (apologies for not being politically correct in this instance)...

Anyway too much skiving off from me.

______________________________________________________________________________________________________________

Long story short the combination of compressive forces (almost forging the surface of the material) and simultaneously work hardening the surface of the material may be causing that "Bite back" effect at the surface. So maybe pilot holes and different sizes and make sure that major forces are not applied and absolutely no heat build up... Sounds like something more subtle is needed (to be programmed also that is more subtle than conventional pecking drilling or plunging... ).

I'd be interested to see how this would go on a manual mill.

On the NVX would have to be to tiny peck, cool, tiny peck, cool, peck-PLUNGE (massive) fast retract... Then repeat as there is no way to do it one... When they figure out how to negotiate the material (by whatever means) I'd be interested to see the G-code on that, as it seems something more subtle / clever might be needed? [All wild guesses].

I've cut a few S7 parts in my time, it can give you headaches if things go bad.
Never cut the material in question though.
Guhring deep hole drills are the cat's ass but I don't think they make one that large of a diameter unfortunately.

Seco Crown Loc drills are good, I doubt any of the big name brands have a bad replaceable tip drill to offer.
Sandvik, Seco, Guhring, Iscar,Kennametal, etc...

cameraman said:

Monarchist beat me too it... And others...

Click to expand...

Not me, personally. Guy named "Hadfield", and brutal lessons learnt the hard way a long time ago. The hint was here:

.5% Manganese

Click to expand...

And in "the usual suspects" it plays so well with:

5.% Chrome
2.3% Molybdenum
.5% Vanadium

Click to expand...