Is there ANY way to drill through hardened tool steel?

[Zach England]

So I have a number of 1/4 inch thick irons from Steve Knight and I'd love to drill a couple of holes in them so I can add chipbreakers. Should I just forget it and order some different irons for my upcoming army of Krenov planes?

[David Weaver]

Order different irons and save those, that would be my first choice (and second, and,...)

I've been able to drill 1095 with HSS bits, but never hardened O1 (never even tried, it's just too close in hardness). Even the hardened 1095 spring steel is very hard on HSS bits and I have to sharpen them every time I drill two holes, and the cuts are not that great - i've probably been just using the HSS bits to run the temper out of the 1095 until they will drill it.

You do have one other option, I guess (and this is just a guess), and that would be to put the business end of the iron in water to keep it cool and try to use a mapp torch to run the temper out of the spot you want to drill (or drill twice and file out into a slot). I have never tried that, but it is an option - one that might be a little easier on a longer and thinner iron.

Steve's irons are probably low 60s in hardness in their hardened state (and they are very good irons, maybe the best I've seen in O1). You really would be better off just getting the right irons for what you want to do.

[Zach Dillinger]

Any particular reason for those chipbreakers? I'd just skip 'em. A 1/4" thick iron is going to see very little benefit from a chipbreaker.

[Zach England]

Any particular reason for those chipbreakers? I'd just skip 'em. A 1/4" thick iron is going to see very little benefit from a chipbreaker.


Because it would make my project more difficult, complicated and expensive, all of which are necessities for anything I do.

[David Keller NC]

to answer the direct question - yes, you can drill through hardened steel with either a carbide bit or a diamond bit. Both of these generally require cooling to avoid cooking the bit and de-bonding the carbide or diamond particles from the substrate. For a chip breaker, though, one usually requires not just a hole, but a slot so that the chipbreaker can be retracted as the iron is sharpened. A commercial metal working shop would be able to do this with either a plasma cutter or a water jet cutter, but both of these options may be more expensive that you wish to pay for a couple of irons.

[john brenton]

Somewhere I read about heating up the iron and putting ashes on the spot where you are going to drill. Debunk away.

[Zach England]

Thanks for the input. I think I'll just go with the irons sans chipbreaker and order some different ones if I run into problems.

[Bruce Page]

Because it would make my project more difficult, complicated and expensive, all of which are necessities for anything I do.
That's my normal MO also.

To answer your question, as David mentioned, it can be done using carbide or diamond tipped bits but it is not something a layman can do on a drill press in his garage, at least not without a lot of frustration. I have drilled out broken taps on the milling machine using a specially ground carbide drill and feeding the drill 2 or 3 thousandths at a time, it’s a tedious process. If you took it to a machine shop they would likely turn the job down unless they had an EDM (Electrical Discharge Machining). An EDM could burn a hole though it in a matter of minutes.

[Ray Gardiner]

Hi Zach,

If you can get some solid carbide slot drills, that would work. I have heard of using a carbide router bit but I've not tried it.

Set the job up properly clamped in a drill press and use cutting lubricant.

Regards
Ray

[Ray Gardiner]

That's my normal MO also.

To answer your question, as David mentioned, it can be done using carbide or diamond tipped bits but it is not something a layman can do on a drill press in his garage, at least not without a lot of frustration. I have drilled out broken taps on the milling machine using a specially ground carbide drill and feeding the drill 2 or 3 thousandths at a time, it’s a tedious process. If you took it to a machine shop they would likely turn the job down unless they had an EDM (Electrical Discharge Machining). An EDM could burn a hole though it in a matter of minutes.

Hi Bruce,

I think we cross posted, I generally agree with your comment about drilling out broken taps, but that's going to be an interrupted cut, and your likely to chip the carbide anyway. The other point is that the plane blades are probably not as hard as a tap, and it's not an interrupted cut. I think it's worth a shot.

Regards
Ray

[george wilson]

You can drill holes right through a file with carbide masonry drills,especially if you grind or hone a negative edge angle on them. The main thing is to not let the bit get too hot,or the brazing of the tip will melt.

I drill out hardened steel at about 2000rpm. The speed lets the carbide ruin the temper in the steel,and then scoop it out. Let the bit cool every 1/16". Actually though,I have drilled right through files without stopping. Buy an extra bit. They are only a few dollars each.

[Bruce Page]

Hi Ray, I haven’t tried using a slot drill. It’s been a while, but I would use a modified carbide pantograph type cutter with a hand ground ~20° tip. I’d run the mill at 2500 RPM and use the quill’s thumb wheel to feed down a couple of thousandths at a time, all the while keeping it flooded in black oil. This process saved my butt a few times when I broke a tap in something too big to move to the EDM and remove.
I have never tried it on a dp but I don’t think a drill press would be rigid enough. I think the quill would wobble under pressure and wipe out the carbide. JMO

[george wilson]

I always just used a drill press. The hardest thing to drill with a masonry bit is HSS. I got a bunch of SOLID HSS power hacksaw blades about .050" thick,and made several kitchen knives out of them. I found that I had to touch up the edge of the masonry bit with a diamond wheel every hole I made for the handle rivets. If not,the blade would pop in two. carbon tool steel,or files are much easier than HSS to drill.

I drilled my holes dry. I was relying upon the carbide making heat to ruin the temper in the hole being drilled,rather than cooling it and relying just upon the carbide cutting the steel. If we have both drilled such holes,it must work either way,but my way is simpler and cleaner and doesn't require anything but a drill press,which may be something the home shop user could do with what he has access to.

For guitar fret files,I also drill and countersink both ends of a Nicholson file. Then,I screw it to a narrow block of wood where you can get a finger grip on it. If the file is a bit hollow,I just put shims behind it,and tighten the screws down to bend the file straight.

[Bruce Page]

George, I know I was a little off topic but I was relaying my experience/process in drilling out High-Speed steel taps. I have never tried to drill a Nicholson file or a hand plane blade.

[Zahid Naqvi]

why not just sell the blades and buy new ones from LV/LN they will easily fit a wooden plane.

[Jim Koepke]

I have cut plane blades with a wheel on a dremel. It wears the wheel quickly, but they are cheap.

jtk

[Mike Siemsen]

I prefer to cut steel with an air powered die grinder with a 3" diameter disk. Dremels have always seemed underpowered to me. Check your plane irons. Many plane irons are only hardened up to the bottom of the slot. Maybe yours are only hard on the first 2 inches. I would get different ones if you really want the slot. You will save time and money and not ruin the irons you have. While you are at it you could buy irons with cap irons already on them and go straight to plane making. If the irons are O-1 and you are determined to use them, anneal them, do your metal work and re-harden.

[Zach England]

How about bevel-up krenov planes? Anyone? Would it be possibly to securely seat a wedge that would not shift in use?

In any event, I have a big stack of these things and am determined to invent a project for them.

[Zach England]

And yes, I understand that I may not necessarily need a chipbreaker with irons this thick and that indeed Mr. Knight does not use chipbreakers in the plane kits he sells. I am just thinking about all the interesting things that I can do with them.

[john brenton]

Wow...that sounds like a serious chore. I'm not sure what wheels you're using, but I used up a butt-load of the thicker "reinforced" ones just the other day cutting up an old sawzall blade. You just watch those little wheels dwindle down to nothing right before your very eyes. Every minute I was unscrewing that little tiny screw to replace the wheel...I'm amazed that I didn't lose it. That's the kind of thing that falls...and POOF...it's gone, then you have to buy a whole new thing just to get another one.


I have cut plane blades with a wheel on a dremel. It wears the wheel quickly, but they are cheap.

jtk

[jim goddard]

I would also recommend a carbide bit or end mill. I had occasion to drill cast iron which is very hard and this type of bit easily cut it.

[Jim Underwood]

Absolutely you can drill through hardened steel- with your drill press.

I bought a Bad Dog Tool drill bit set so I could make parting knives out of some air hardening spring steel. I wrecked two or three standard HSS bits and a couple of masonry bits even after spot annealing with a nail and a really high RPM drill press.

Finally I just bought the set and punch right through the stuff now.

The guy who demos these at the woodworking shows drills through files, taps and HSS drills all the time.

I'm not a representative of the company, just a satisfied customer.

http://www.baddogtools.com/dotnetnuke/

[george wilson]

I can't tell from the little picture if those bad dog drills have a carbide tip.

Years ago I suckered in and bought a 5 piece set of German carbide tipped drills at a woodworking show. they had files laying around 1/4" thick,that looked like Swiss cheese. I was in a hurry,and didn't look at them closely. After I got home,I found that the drills were exactly like masonry bits,but with a negative ground cutting edge on them. I used them,but just used masonry bits when the German drill's tips would get too hot and the brazing would let go. Sometimes I'd bother to grind a negative cutting edge,but most often I just used them straight,touching up their cutting edges as said,after drilling through HSS hacksaw blades.

Since I've actually drilled out many holes in hardened steel and HSS,I guarantee you will do just fine IF you follow my directions. Those small size masonry bits are about $2.75 each,IIRC. I'd buy a few,and if you melt the brazing off one,be more careful with the next one. After drilling a few holes,you'll gain the experience to do fine every time.

I also use small carbide end mills to drill out broken HSS taps. You should NEVER use an end mill in your drill press,because they will also cut sideways(as designed),and will grab and ruin your blade with an unsightly gash. A milling machine with a vise prevents sideways grabbing from happening. The milling machine's spindle is also stout enough to not allow sideways flexing,where the end mill can grab.

[Luke Townsley]

If you are good, I believe you could do it with a hand held oxy/fuel cutting torch and a #0 or #1 tip. You would have to get some heat into it to get it to cut right (just the plunge hole would probably be enough or almost enough as long as the steel was room temperature to start with, but not so much heat as to loose the temper of the business end. You would have to run the torch fairly "cold" and cut fast. And you would run the risk of cracking it if you used water. I think I could have done it pretty easily with a burning machine when I used to work in a steel shop, but I'm probably not steady enough to do it by hand, but some welders would be. Of course, if you have a way to clean it up with a grinder of some sort after the fact, then neatness isn't quite as important.

[Jim Underwood]

I can't tell from the little picture if those bad dog drills have a carbide tip.

Yep they do. And I do believe they're a tad tougher than regular masonry bits because at the demo they bang 'em like there's no tomorrow and they don't chip like masonry bits do. I've chipped up plenty of masonry bits in the past.
There's a lifetime warranty on these bits, and they'll sharpen them for you too. If you follow the directions, I don't believe you'll melt the brazing off, but it could happen. If it does the company will replace 'em, no questions asked.

Anyway, you might think they're too pricey at $90 set, but mine paid for themselves after selling a few of my parting tools...

[Leigh Betsch]

Hole poper EDM. "drill" it with a piece of $10 copper. Course the hole popper will cost you $20k (used).

[Fred Krow]

Send it to a machine shop and have them Wire EDM the slot you require.
They would use a Plunge EDM to make the initial hole then any shape could be made with the wire EDM.

No mess up of hardness and a nice neat edge.

Regards,
FK

[Johnny Kleso]

You can drill it with a carbide spade drill but you will only have a hole not a slot..
You can water jet a slot (high pressure water and grit in a fine stream)

Worth it ??? I dont think so..

[Ed Looney]

Yes you can drill through tool steel. Rodman & Company sells drill bits that will drill through a file without coolant. I have used them to drill holes in hardened dowel pins. The trick with these drills is to spin them at the recommended RPM.

If you are interested in these drills you can view their web sight here.
http://www.rodmanandcoinc.com/rodmanandcoinc.com/item04c5-2.html?UCIDs=1307321%7C1307323&PRID=1492961

[Johnny Kleso]

This type is best for very hard material
http://www.travers.com/product.asp?RequestData=CA_Search&q=item_id+'20-420-184'&catalog=100266

194301

[george wilson]

I use those type too,Johnny,but they cost a lot more than masonry bits. I tend to use the cheapest consumable drilling tool I can get by with for non critical diameter jobs. I have the means to sharpen those solid carbide drills,but most won't.