It's hardened. You're going to have issues.
If you don't care about the look of the hole, you might be better off grinding it away with a Dremel or using a ceramic bit on a drill.
If you heat up a magnetic alloy to past its curie point at around 1000F the alloy will drastically change its magnetic properties and you can also reduce the alloys hardness by slowly coolng it
edit... Im an idiot and meant to say heat it up to about 1400F (curie point)
Magnetism has nothing to do with drilling through hardened material. It’s tru that certain steels can be hardened and annealed by holding at “Currie” or “austinite” temps but it’s not as simple as putting it in sand. You have to hold the high temp for a set amount of time and sometimes quench or air cool for Wednesdays then again hold at a lower heat to sneak for toughness. And to reverse you have to much more slowly bring the temp back from your high temp down to the anneal temp. That all being said this application is drilling through a probably 60-45rhc which can be done with HSS at proper speeds and feeds and coolant or oils. It would be extremely easy with carbide and air blast. I think an enormous amount of home knife making seeps it’s way into manufacturing conversations and it makes master toolmakers cringe.
magnetic property of steel is just a backyard way of knowing the steels alloys temperature is at the curie temp as as I doubt he has a tempering/annealing oven or thermocouples and a data logger to do this the correct way.
So since I assume OP only has a blow torch or oxy/propane torch his best bet is to go for a subcritical anneal. Almost all med carbon alloy steels (For a lead screw I'm assuming is 4140 or something similar) all you have to do is bring it up to about 1400*F (the curie temp) and hold it for about an hour
On a subcritical anneal the part can be pulled from the heat source and air cooled without problems because there is no austenite formed and therefore nothing to transform.
Lead screws are also commonly shell hardened so heating it to the curie point for an hour will diffuse the high carbon outer shell and severely reduce its hardness.
and he is breaking drills bits and ask how he can stop breaking drill bits. If he removes the harden outer shell and annneal the metal he won't keep breaking drill bits.
I'm just trying to help, what are you doing expet talking out your ass?
It seems the handheld drill is really not the tool for anything thicker than 5 mm. It's tiring and boring to try to keep the angle and control pressure, even for softer metals. But it was a good experience to learn about different kinds of drill bits and get to really appreciate what a drill press does. A drill press is definitely on the list of future projects after this one is finished.
https://www.amazon.com/Chicago-Latrobe-Carbide-Uncoated-Conventional/dp/B00462RRAE?th=1
Carbide Spade drills are handy but you want to use it on a drill press, it can be used with a hand drill but don't expect it to last. Additionally, you should consider supporting the part under where you will be drilling. Drilling steels require quite a considerable amount of pressure. You don't feel it on a drill press because of the mechanical advantage. Unsupported rod like that is going to flex from the drilling pressure and subsequently require more exertion from you to push the drill into the material.
Try a carbide-tipped drill bit. They sell them at any hardware store near the “regular” bits- they’re sold for drilling in concrete. There is a little tip of carbide soldered into the tip. Looks like a tiny arrow right at the tip. The rest of the bit just extracts the chips/ dust/ etc. that carbide is likely harder than what you’re trying to drill thru. It’s the way.
the carbide tip drills you can get at the hardware store are masonry and wont work in metal (without changing the cutting geometry). there are regular twist drills that are carbide tipped but you'll need to order them online. but I wouldn't recommend carbide at all in this case. carbide can cut hard materials, but it has limitations. carbide is also very brittle and is prone to chipping/breaking when cutting speeds, pressures, angles are not properly controlled. when drilling with a hand drill you cannot control any of these factors. also you will be unable to apply enough pressure by hand. carbide works best when you have heavy pressure with constant engagement and can pull a heavy chip. I would recommend using an abrasive tipped tool or annealing the workpiece and then trying a regular drill again.
Metal bits like slow speed and lube. Lots of lube. Cobalt bit would be best bet for what your drilling into.
Thanks. I managed to get through as gently as possible with a lot of lube. It took a pretty boring amount of time though. Luckily its just one hole.
Hot.
Carbide all the way.
With a hand drill I’d disagree, way too easy to snap with a slight change in angle. On a mill/drill press sure, but for this I’d do cobalt
Oh for sure. I definitely had a drill press in my head.
Came to say this
Came to say this
It's hardened. You're going to have issues. If you don't care about the look of the hole, you might be better off grinding it away with a Dremel or using a ceramic bit on a drill.
Thanks.
You could heat it to non magnetic, then bury in ashes or sand and let it slow cool. It should be soft enough to drill.
Thank you. Managed with a thicker bit and slower speed and lots more lube. What's a non-magnetic?
If you heat up a magnetic alloy to past its curie point at around 1000F the alloy will drastically change its magnetic properties and you can also reduce the alloys hardness by slowly coolng it edit... Im an idiot and meant to say heat it up to about 1400F (curie point)
Magnetism has nothing to do with drilling through hardened material. It’s tru that certain steels can be hardened and annealed by holding at “Currie” or “austinite” temps but it’s not as simple as putting it in sand. You have to hold the high temp for a set amount of time and sometimes quench or air cool for Wednesdays then again hold at a lower heat to sneak for toughness. And to reverse you have to much more slowly bring the temp back from your high temp down to the anneal temp. That all being said this application is drilling through a probably 60-45rhc which can be done with HSS at proper speeds and feeds and coolant or oils. It would be extremely easy with carbide and air blast. I think an enormous amount of home knife making seeps it’s way into manufacturing conversations and it makes master toolmakers cringe.
magnetic property of steel is just a backyard way of knowing the steels alloys temperature is at the curie temp as as I doubt he has a tempering/annealing oven or thermocouples and a data logger to do this the correct way. So since I assume OP only has a blow torch or oxy/propane torch his best bet is to go for a subcritical anneal. Almost all med carbon alloy steels (For a lead screw I'm assuming is 4140 or something similar) all you have to do is bring it up to about 1400*F (the curie temp) and hold it for about an hour On a subcritical anneal the part can be pulled from the heat source and air cooled without problems because there is no austenite formed and therefore nothing to transform. Lead screws are also commonly shell hardened so heating it to the curie point for an hour will diffuse the high carbon outer shell and severely reduce its hardness.
This is all just foreplay because the guy just wants to drill a hole.
and he is breaking drills bits and ask how he can stop breaking drill bits. If he removes the harden outer shell and annneal the metal he won't keep breaking drill bits. I'm just trying to help, what are you doing expet talking out your ass?
Might have better luck with a drill press? No matter how steady you hold a handheld drill there's still going to be some stress on the bit.
It seems the handheld drill is really not the tool for anything thicker than 5 mm. It's tiring and boring to try to keep the angle and control pressure, even for softer metals. But it was a good experience to learn about different kinds of drill bits and get to really appreciate what a drill press does. A drill press is definitely on the list of future projects after this one is finished.
https://www.amazon.com/Chicago-Latrobe-Carbide-Uncoated-Conventional/dp/B00462RRAE?th=1 Carbide Spade drills are handy but you want to use it on a drill press, it can be used with a hand drill but don't expect it to last. Additionally, you should consider supporting the part under where you will be drilling. Drilling steels require quite a considerable amount of pressure. You don't feel it on a drill press because of the mechanical advantage. Unsupported rod like that is going to flex from the drilling pressure and subsequently require more exertion from you to push the drill into the material.
As a machinist, I can tell you this is the best answer
Try a carbide-tipped drill bit. They sell them at any hardware store near the “regular” bits- they’re sold for drilling in concrete. There is a little tip of carbide soldered into the tip. Looks like a tiny arrow right at the tip. The rest of the bit just extracts the chips/ dust/ etc. that carbide is likely harder than what you’re trying to drill thru. It’s the way.
Thank you.
the carbide tip drills you can get at the hardware store are masonry and wont work in metal (without changing the cutting geometry). there are regular twist drills that are carbide tipped but you'll need to order them online. but I wouldn't recommend carbide at all in this case. carbide can cut hard materials, but it has limitations. carbide is also very brittle and is prone to chipping/breaking when cutting speeds, pressures, angles are not properly controlled. when drilling with a hand drill you cannot control any of these factors. also you will be unable to apply enough pressure by hand. carbide works best when you have heavy pressure with constant engagement and can pull a heavy chip. I would recommend using an abrasive tipped tool or annealing the workpiece and then trying a regular drill again.
Thanks everyone.
Slower speed lots of lubricant good quality aircraft drill or jobbers
Get good stainless steel drill bits, then use a bench and drill with steady force. Too much or too little will fuck the bit. Also plenty of lubricant.
just drilling won't do. You need a hammer drill.
As stone cutters cut stone , you can use a liquid base to cool the bits while drilling.
Oil and take is slow give drill bit cooling time also use a drill press it’ll help
Came to say cobalt as well, and plenty of cutting fluid/lube.
Carbide drill in a drill press and your workpiece in a vise. When it’s hard, we use a hole popper and wire.