Is a 1/2hp drill press sufficient for 1/4" holes in hardened steel chisels?

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Old 06-12-14, 12:50 AM
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Is a 1/2hp drill press sufficient for 1/4" holes in hardened steel chisels?

Hi, I need to drill 1/4 inch holes through the blades of Irwin M44434N hardened steel chisels. Using a cobalt bit, about how long will it take per hole using the cheapest $62.99 Harbor Freight #60238 1/2hp drill press? How many holes will I get before needing to change the bit?
 
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Old 06-12-14, 03:40 AM
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Not so much the drill press (which 1/2 hp is plenty big), but the number of bits you will go through. I have to ask in all fairness, just why do you see the need to drill holes in chisels? The chisel will be basically worthless as a chisel after you do this, you know that, right?
 
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Old 06-12-14, 03:58 AM
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I have HF drill press but I think mine is just 1/3 hp. I've had it for 25-30 yrs and it's worked well for me. The main thing when drilling hard steel is to go slow and keep the bit lubricated! The bits can be resharpened.

I'm also curious as to why you are drilling chisels ??
 
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Old 06-12-14, 05:49 AM
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Like Chandler has already said. It's not the power of the drill press. Even a cordless hand drill will have enough power to turn the bit. The hard part is finding a bit that is harder than the hardened steel chisel you're trying to drill.

I'd consider annealing the drill area to make drilling easier depending on what you want to do with the chisel afterwards. If you leave the chisel hard I would pilot drill with about a 1/8" and maybe use an intermediate size before drilling the 1/4". You'll want either cobalt (not the brand but the type of steel used to make the bit) drill bits with a titanium coating or carbide tipped bits. Cobalt drill bits do not handle heat well so make sure to keep the work lubricated to ease cutting and to cool the bit.
 
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Old 06-12-14, 10:49 AM
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Depending on how many you need done, it might be cheaper/faster/easier at a machine shop or a water jetting place. Of course, you won't have the press afterwards, but you also won't spend $50 on bits.
 
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Old 06-12-14, 12:47 PM
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But Vic! how are we supposed to fill our shops if we don't use every excuse we can find to buy a new toy and it's accessories
 
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Old 06-12-14, 11:07 PM
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I need to add ball bearings for better control when removing old window glazing compound. My usual source wants $28 for each chisel, so I figure I'd make them myself. But if it takes an hour to drill one and chews up three cobalt bits, it won't make sense to make them myself, so I was wondering how much time it will take and how many chisels I'll get per bit (or, how many bits I'll need per chisel.) Any estimates?
 
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Old 06-12-14, 11:49 PM
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A heat gun and a putty knife will remove the glazing.
 
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Old 06-13-14, 02:44 AM
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EPA rules prohibit heat guns on lead paint. I get better results anyway with infrared and microwave. Putty knives don't give precise enough control over the depth of the cut, risking glass breakage. The roller chisels work best. I just need advice on drilling the holes.
 
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Old 06-13-14, 04:04 AM
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Have you given thought to a tool meant for the purpose? I have one of these and it works well. Prazi USA PR9000 Putty Chaser - Power Drill Accessories - Amazon.com
 
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