Not really a gunsmithing question but i'm sure there are plenty of you who have knowledge of working with hardened metal. I bought some Hardox600 plates (much like AR500 just 600 brinell hardness) and i have a serious lack of professional equipment. I tried drilling holes trough it (got the Cobalt drill, used coolant however i don't have fixed drill stand or a mill) using hand drill, however i get to somwhere 0.1" and then drill just stops drilling and doesn't bite anymore (it's not dull mind you as i can easily go trough normal steel). I get same result from small bits or .25" (as this is the hole i want). I don't want to take tamper off the plate with using blow torch or gas cutter. Is fixed stand or mill only option for drilling such material or am i just doing something wrong.
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Gunsmithing Drilling hardened steel
- Thread starter sharac
- Start date
Re: Drilling hardened steel
Dont know the properties of that material but it sounds like it is work hardening , using a drill press or mill will certainly work better especialy is you use a carbide bit.
You probably running to many RPMs and not enough pressure with the hand drill , trouble it if you lean into it for more pressue then you run the risk of breaking the bit beacuse your can't hold even down pressure.
Either try a drill press or find sombody with a water jet
Dont know the properties of that material but it sounds like it is work hardening , using a drill press or mill will certainly work better especialy is you use a carbide bit.
You probably running to many RPMs and not enough pressure with the hand drill , trouble it if you lean into it for more pressue then you run the risk of breaking the bit beacuse your can't hold even down pressure.
Either try a drill press or find sombody with a water jet
Re: Drilling hardened steel
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">risk of breaking the bit</div></div>
2 small ones gone with the wind
...
I guess i'll have to go to a pro i was just impatient trying to do it over weekend...
Thanks for advice anyway.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">risk of breaking the bit</div></div>
2 small ones gone with the wind
I guess i'll have to go to a pro i was just impatient trying to do it over weekend...
Thanks for advice anyway.
Re: Drilling hardened steel
Just to add (if anyone considers similar endeavor), drilling with drill stand and various drill bits didn't work, it starts cutting but somewhere in the middle gets stuck and doesn't do much (got info from Ssab that plate gets tougher from the surface on). What did the job was a mill machine with a carbide cutter (something like this ) and even that with huge amounts of pressure, cooling liquid and arround 600rpm. After the 10th hole cutter started to get a bit dull and even more pressure was required...
Was a pain to do this job but the plate is finished now should be a nice gong ( i just hope it will live up to its 600 brinells)...
Just to add (if anyone considers similar endeavor), drilling with drill stand and various drill bits didn't work, it starts cutting but somewhere in the middle gets stuck and doesn't do much (got info from Ssab that plate gets tougher from the surface on). What did the job was a mill machine with a carbide cutter (something like this ) and even that with huge amounts of pressure, cooling liquid and arround 600rpm. After the 10th hole cutter started to get a bit dull and even more pressure was required...
Was a pain to do this job but the plate is finished now should be a nice gong ( i just hope it will live up to its 600 brinells)...
Re: Drilling hardened steel
What you needed is a tungsten carbide tipped bit. The carbide is sweated to the drill
tip and is very brittle. They are a little pricey and easy to break so a drill press
would be in order. You've seen hammer drills/masonry bits that are made that way
I'm sure.
What you needed is a tungsten carbide tipped bit. The carbide is sweated to the drill
tip and is very brittle. They are a little pricey and easy to break so a drill press
would be in order. You've seen hammer drills/masonry bits that are made that way
I'm sure.
Re: Drilling hardened steel
Tried all that can be done on AR500 armor plate, ended up taking it to a guy who cuts metal with a hydro-cutter (water jet cutter). Cut through it like butter. Took less time then it took me to drive it over to him.
Tried all that can be done on AR500 armor plate, ended up taking it to a guy who cuts metal with a hydro-cutter (water jet cutter). Cut through it like butter. Took less time then it took me to drive it over to him.
Re: Drilling hardened steel
10mm (4/10" approx) and i've tried several inox/hardened steel bits (i sure as hell didn't want to spend more than 30$ on a drill bit) which i had but no joy. Well this milling machine did it and i'm quite happy. I tried the same bits that wouldn't cut this piece on some other pieces and they made holes as expected so at lest i didn't ruin them...
Water jet is the way to go for sure but as my neighbor had this milling machine i first tried the easy way (couple of beers and an afternoon) and backup plan was either EDM or water jet and -few$...
PS: I probably overcomplicated matters as i'm pretty sure even using torch to make holes would be acceptable and would make material softer only locally i was just intrigued as to what it would take to drill trough it and if it was doable by hand (i'm an IT man bored with its current job and kinda like meddling with tools and machines...)
10mm (4/10" approx) and i've tried several inox/hardened steel bits (i sure as hell didn't want to spend more than 30$ on a drill bit) which i had but no joy. Well this milling machine did it and i'm quite happy. I tried the same bits that wouldn't cut this piece on some other pieces and they made holes as expected so at lest i didn't ruin them...
Water jet is the way to go for sure but as my neighbor had this milling machine i first tried the easy way (couple of beers and an afternoon) and backup plan was either EDM or water jet and -few$...
PS: I probably overcomplicated matters as i'm pretty sure even using torch to make holes would be acceptable and would make material softer only locally i was just intrigued as to what it would take to drill trough it and if it was doable by hand (i'm an IT man bored with its current job and kinda like meddling with tools and machines...)
Re: Drilling hardened steel
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> i'm pretty sure even using torch to make holes would be acceptable and would make material softer only locally </div></div>
I wouldn't count on it. Millwrights cut out a couple of liner plates (AR500) and blew the holes in it with a CNC plasma. All that was left was for me to do countersink the holes. They didn't check the hole size, ended up undersized. A HSS countersink won't scratch the holes... It's gonna be cheaper to buy more plate and start over (leaving the holes for me to put in) then buying the carbide tooling to save the plates.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> i'm pretty sure even using torch to make holes would be acceptable and would make material softer only locally </div></div>
I wouldn't count on it. Millwrights cut out a couple of liner plates (AR500) and blew the holes in it with a CNC plasma. All that was left was for me to do countersink the holes. They didn't check the hole size, ended up undersized. A HSS countersink won't scratch the holes... It's gonna be cheaper to buy more plate and start over (leaving the holes for me to put in) then buying the carbide tooling to save the plates.
Re: Drilling hardened steel
Generally the way to do it is use a small torch tip or a carbon electrode to spot heat (and anneal) where you want to drill the hole. It softens the metal at the drill spot so that the tooling will cut it. If I was getting items made from AR500 I would just have them waterjetted, as you found out, it goes through plate pretty damn quick.
Generally the way to do it is use a small torch tip or a carbon electrode to spot heat (and anneal) where you want to drill the hole. It softens the metal at the drill spot so that the tooling will cut it. If I was getting items made from AR500 I would just have them waterjetted, as you found out, it goes through plate pretty damn quick.
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