Trouble Drilling

T

theTrashMan

Joined
Feb 6, 2018
Messages
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Hello everyone, it's been a while since I've been on these forums, but it's come to my attention that I may need the community's help. So I've purchased some 1080 to make some blades, and I've been stuck without a belt sander for a bit. So I decided I'll hand file the blades while I wait for my belt sander to arrive, so I decided to fully anneal the blades to make my life a little easier. However it's seemed to do the contrary, and I've been unable to drill pinholes for my knives, which is, really confusing. It's not the drill press, because it works on my other steels, and it's not the drill bits because I tested them on both the 1080 and on some 1095 (both 1/8") and it worked fine for the 1095. Not to mention I bought new bits but they can't get through the 1080. Any tips? What do I do? is there a specific speed my drill press should be on? (it's at 750 RPM right now), or am I doomed to not have pinholes for my knives?
-The Garbage Man
 
Google Artu drill bits, and these are to be used in a drill press only.
When inspected up close they look like an ordinary masonry drill bit, but i've found the piece of carbide in the tip to be of a noticeably harder quality.
Used them in the past to drill through a fully hardened M2 steel machine hacksaw blade.
 
First of all, what size holes are you trying to drill? If anything much over 1/8" your speed is too fast for a HSS drill. If you're drilling 1/8" holes and having trouble, you're either going to need to do a proper annealing or get a carbide drill. I would steer clear of the masonry style - look for a spade bit, like this:

https://www.amazon.com/Chicago-Latrobe-High-Speed-Uncoated-Conventional/dp/B006O2S4XI

Speed is important for cutting tools. You need to get it right with difficult materials (like hardened steel) or you will trash the tool.
 
eKretz said:
First of all, what size holes are you trying to drill? If anything much over 1/8" your speed is too fast for a HSS drill. If you're drilling 1/8" holes and having trouble, you're either going to need to do a proper annealing or get a carbide drill. I would steer clear of the masonry style - look for a spade bit, like this:

https://www.amazon.com/Chicago-Latrobe-High-Speed-Uncoated-Conventional/dp/B006O2S4XI

Speed is important for cutting tools. You need to get it right with difficult materials (like hardened steel) or you will trash the tool.
Click to expand...
Hm, I'm trying different bits, at first I was attempting to use an 8D nail for a pin, but since the bit didn't seem to like that, I switched to a quarter inch bit because I have some pin material for that, but it doesn't work either. The bits I'm using are black oxide and cobalt (all new) and I annealed the steel (red hot to room temp air cooling). Any recommended speed for quarter inch?
 
Where did the 1080 come from?
How did you heat it "red hot".
Have you removed the scale? ( soak in PH down solution or vinegar overnight)

Scale is a likely culprit. It is much harder than people think.
The annealing you did isn't the best. Try heating to just below magnetic ( don't let it get non-magnetic) and holding it there for a while if possible. Then stick in a big can of ashes or vermiculite to cool slowly overnight.
 
eKretz said:
First of all, what size holes are you trying to drill? If anything much over 1/8" your speed is too fast for a HSS drill. If you're drilling 1/8" holes and having trouble, you're either going to need to do a proper annealing or get a carbide drill. I would steer clear of the masonry style - look for a spade bit, like this:

https://www.amazon.com/Chicago-Latrobe-High-Speed-Uncoated-Conventional/dp/B006O2S4XI

Speed is important for cutting tools. You need to get it right with difficult materials (like hardened steel) or you will trash the tool.
Click to expand...

Generally speaking 750 is not too fast for a 1/4" drill in knife steel, it's about right. I do 900, no pecking, with coolant. Done dry on a drill press 750 is usualy fine. Other than the drill quality and material condition the key is to adequately feed.

I suspect the root cause of his problem is hitting sheets of carbide in the steel. Spheroidizing the steel would help. Simply feeding harder might work. A specialty carbide drill designed for this application would probably work. As a general rule carbide drills suck in steel for most home shop setups.

Running the drill slower, within reason, won't hurt anything but most of the time the answer is to feed harder. Just remember to reduce feed pressure as the web exits the back of the workpiece or you will overfeed and wipe out your corners.
 
Nathan the Machinist said:
Generally speaking 750 is not too fast for a 1/4" drill in knife steel, it's about right. I do 900, no pecking, with coolant. Done dry on a drill press 750 is usualy fine. Other than the drill quality and material condition the key is to adequately feed.

I suspect the root cause of his problem is hitting sheets of carbide in the steel. Spheroidizing the steel would help. Simply feeding harder might work. A specialty carbide drill designed for this application would probably work. As a general rule carbide drills suck in steel for most home shop setups.

Running the drill slower, within reason, won't hurt anything but most of the time the answer is to feed harder. Just remember to reduce feed pressure as the web exits the back of the workpiece or you will overfeed and wipe out your corners.
Click to expand...

No, not if it is fully hard. That's pushing 50 SFM, and would easily destroy an 1/8" drill nearly instantly. If he's only around 30Rc then he'd be okay at that speed
 
eKretz said:
No, not if it is fully hard. That's pushing 50 SFM, and would easily destroy an 1/8" drill nearly instantly. If he's only around 30Rc then he'd be okay at that speed
Click to expand...
Perhaps I misread, are we talking about fully hard material?
 
Dang it. Had a whole big reply and it got erased somehow. Anyway, it seems that it's been accidentally hardened to quite a high level if he can't get through with new drills. We need more info from the O.P. The spade drills I recommended ARE designed for just this application - drilling through small L : D ratio hard steel. Regarding the hole exit, I'd recommend putting another piece of steel behind the blade and clamping them together. This will prevent any accidentally overfeed on exit.

And I worked in machine shops for over two decades, I have a little experience as well.
 
Last edited:
theTrashMan said:
Any tips? What do I do? is there a specific speed my drill press should be on? (it's at 750 RPM right now), or am I doomed to not have pinholes for my knives?
-The Garbage Man
Click to expand...
Buy this and you can drill hole in anything you want ..........
WRYAN70.jpg



I finally find time to make short video so you can see how this drill bits drill some crazy hard steel ... like in cake ;) Speed is 515rpm/min but ordinary I drill on 900 with this drill bits .This is small drill press so I need my two hand to put right pressure but because I hold phone in one hand I can t do that ...You don t need any coolant ...just drill :thumbsup:
https://www.bladeforums.com/threads/sharpening-masonry-drills.1540592/
 
kwackster said:
Google Artu drill bits, and these are to be used in a drill press only.
When inspected up close they look like an ordinary masonry drill bit, but i've found the piece of carbide in the tip to be of a noticeably harder quality.
Used them in the past to drill through a fully hardened M2 steel machine hacksaw blade.
Click to expand...
I got them but I've never tried them . I can not find them where I left them , it's been three years since then :D I think besides the quality of carbide tip ,the difference is in how they are sharpened . I sharpened cheap masonry drill and they easy drill HSS steel too ............
 
theTrashMan said:
Hm, I'm trying different bits, at first I was attempting to use an 8D nail for a pin, but since the bit didn't seem to like that, I switched to a quarter inch bit because I have some pin material for that, but it doesn't work either. The bits I'm using are black oxide and cobalt (all new) and I annealed the steel (red hot to room temp air cooling). Any recommended speed for quarter inch?
Click to expand...

Oh, missed the question about speed. Since you've updated to say you're using a 1/4" drill, try running at about 300 rpm with the cobalt drill. That's about 20 SFM, and if the drill won't hold up at that speed you're probably going to need carbide if you can't get a good annealing. And I agree with Mr. Apelt - heat and hold, then slow cool. You can use a bucket of sand as well. Not a bad idea to preheat the sand either, so there's no sudden temperature change sticking the blade into a bucket of cold sand.
 
Hello everyone, thank you for all the tips, I'm going to be trying all of them (except maybe not buying more drill bits, as I am not very good with money) I didn't remove scale, so I will be trying that out and re annealing with the tips given by Stacy over the coming weekend. Thanks very much and I will keep you posted
 
Post a picture of the cutting edge end of your drill. If it's in bad shape you should either sharpen it or use a new one if you don't have the capability.
 
Not much to add. If it's hot rolled, there may be hard spots throughout. I've not had tremendous luck "home annealing" carbon steels to dead soft, unless you can really slow down and control the cooling.

Regardless of material, assuming you have a sharp bit, feeds and speeds are the key. A little cutting fluid may help. Be forceful/purposeful with the down feed, and watch the chips. You don't want to "punch" the bit through the steel, but you don't want to feather it either.
 
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