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Drill bits for 1/4" steel?

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If it's just mild steel, most any HSS bit will work. TiN-coated bits are better (and I have never seen the coating flake off) and just turn into regular bits when the coating is worn through. Cobalt bits are the best.

As always, you get what you pay for. Cheap bits aren't straight and wear quickly.

Wear the appropriate safety equipment and always center punch your hole centers before drilling.
 
Solid cobalt is about the best price/performance you'll get for home usage. Make sure you keep the drill straight, with consistent pressure. Oil is a must, and make sure you look to see if chips are spirAling out of both flutes, if not, ones toast and the other will be shortly 😛
 
Triumph said:
Actually I do, and I realized that it didn't matter too much because the guy is not running a machine shop, he just wants to put a hole in something for a stupid home job.
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Get off your high horse Triumph, If you bothered to read, I just told you how to make a drill guide out of wood, so the guy can put a hole in something successfully. Its the difference between leaving a giant burr on the material, and a bent and dull dull drill after just one hole.

All it takes is two scrap pieces of wood and one or two c-clamps. How hard to understand is that?

And if you ever open up your mind, one can learn to drill hard to drill materials like glass, stone, and even ceramics using primitive home equipment.
 
Triumph said:
Actually I do, and I realized that it didn't matter too much because the guy is not running a machine shop, he just wants to put a hole in something for a stupid home job.
Click to expand...
-----------------------------------------------------------------------------------------Get off your high horse Triumph, If you bothered to read, I just told you how to make a drill guide out of wood, so the guy can put a hole in something successfully. Its the difference between leaving a giant burr on the material, and a bent and dull dull drill after just one hole.

All it takes is two scrap pieces of wood and one or two c-clamps. How hard to understand is that?

And if you ever open up your mind, one can learn to drill hard to drill materials like glass, stone, and even ceramics using primitive home equipment.
 
stargazr said:
I doubt he'll get it that hot.

"High-speed tool steels have in common the ability to maintain high hardness at elevated temperatures: typically, 52 HRC at 540 °C (1000 °F) and 48 HRC at 595 °C (1100 °F). Thus, as the term high-speed implies, these steels are primarily used for cutting tools that generate considerable heat during highspeed machining of steels and other metals. In addition to excellent hot hardness, sometimes referred to as red hardness because of the ability of the highspeed steels to resist softening even when red hot, the high-speed steels possess a number of unique alloying and processing features. These features include sufficient alloy and carbon content to provide excess alloy carbides in heat-treated tools, hardening at temperatures close to or at their melting points, hardening with fine austenitic grain sizes, deep hardening by cooling in still air, and prominent secondary hardening during tempering."


The Materials Information Society


http://www.asminternational.org/por...toid=ccd394be27de9110VgnVCM100000701e010aRCRD
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key word is resist. use a tool long enough and it will break 😛

but yeah, a HSS bit should do just fine. like i said - just go slow and use plenty of lubricant and he'll be good to go!
 
Lemon law said:
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Get off your high horse Triumph, If you bothered to read, I just told you how to make a drill guide out of wood, so the guy can put a hole in something successfully. Its the difference between leaving a giant burr on the material, and a bent and dull dull drill after just one hole.

All it takes is two scrap pieces of wood and one or two c-clamps. How hard to understand is that?

And if you ever open up your mind, one can learn to drill hard to drill materials like glass, stone, and even ceramics using primitive home equipment.
Click to expand...

Get off MY high horse??? Hahaha...you're the one that came in here to post 1/4 of the Machinery Handbook when it clearly wasn't necessary, for no other reason than to say to everyone, "Hey everyone look, I'm a machinist and none of you know what you're talking about!" 🙄
 
BlackTigers said:
Solid cobalt is about the best price/performance you'll get for home usage. Make sure you keep the drill straight, with consistent pressure. Oil is a must, and make sure you look to see if chips are spirAling out of both flutes, if not, ones toast and the other will be shortly 😛
Click to expand...

so if the bit is no longer sharp, how do i sharpen it?
file?

or dont bother and buy another one?
even for 3/8" or 1/2" bit?
 
110814_16lo.jpg


the difference? a metal case. 😀

Also, the product in my link is made in the USA and specifies the exact steel type (M42)
I don't know my steels very well, but the import bits may be of lower cobalt content (e.g. M35)

Also also, my link has free shipping; so the actual price difference is $40 (to my zip code at least)
 
Jaepheth said:
110814_16lo.jpg


the difference? a metal case. 😀

Also, the product in my link is made in the USA and specifies the exact steel type (M42)
I don't know my steels very well, but the import bits may be of lower cobalt content (e.g. M35)

Also also, my link has free shipping; so the actual price difference is $40 (to my zip code at least)
Click to expand...
Might not even be cobalt tool steel at all.
 
Well hell, if you are drilling steel or cast Iron, why accept inferior substitutes, or debate the difference between ordinary M2 HSS or genuine M-42 cobalt grades. Or pay for Titanium Nitride coated drills in either HSS grade?

Why not buy the best, a solid carbide drill in either C-2 for cast Iron or C-6 for mild steel.

A 1/16 to 3/8 drill index in 1/16 increments will only set you back a grand. And their edges won't soften at 1400 degrees F, a full 200 degrees better than M-42 Cobalt.

And the answer is an remains, the typical home person who does not know what they are doing will break such a solid carbide drill on the first hole.

M-2 and M-42 cobalt drill are fairly forgiving and will take a lot of abuse. A super brittle carbide drill will break at any abuse.

And I had to laugh my head off at the OrooOroo posted video of the performance of 13/16 super duper cobalt drill in mild steel. Using a $50,000 dollar plus CNC drill that only made 500 holes in an hour with no coolant. And at the end they showed the chips being swept up. Not even a slightly blue or even brown chip in the bunch. In Industry any foreman would be screaming at the operator, for running far too slow. In mass production you can't afford to have a super expensive machine operating at half its potential. Without at least brown chips, M-2 HSS steel would do equally well. And they only showed the front face, as the rear face may need a super expensive deburring operation.
 
Lemon law said:
Well hell, if you are drilling steel or cast Iron, why accept inferior substitutes, or debate the difference between ordinary M2 HSS or genuine M-42 cobalt grades. Or pay for Titanium Nitride coated drills in either HSS grade?

Why not buy the best, a solid carbide drill in either C-2 for cast Iron or C-6 for mild steel.

A 1/16 to 3/8 drill index in 1/16 increments will only set you back a grand. And their edges won't soften at 1400 degrees F, a full 200 degrees better than M-42 Cobalt.

And the answer is an remains, the typical home person who does not know what they are doing will break such a solid carbide drill on the first hole.

M-2 and M-42 cobalt drill are fairly forgiving and will take a lot of abuse. A super brittle carbide drill will break at any abuse.

And I had to laugh my head off at the OrooOroo posted video of the performance of 13/16 super duper cobalt drill in mild steel. Using a $50,000 dollar plus CNC drill that only made 500 holes in an hour with no coolant. And at the end they showed the chips being swept up. Not even a slightly blue or even brown chip in the bunch. In Industry any foreman would be screaming at the operator, for running far too slow. In mass production you can't afford to have a super expensive machine operating at half its potential. Without at least brown chips, M-2 HSS steel would do equally well. And they only showed the front face, as the rear face may need a super expensive deburring operation.
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Not all plants use their super expensive machines in high volume.
 
I will also suggest a cobalt drill bit. They hold up very well. Also a slow drill speed is best and you should use a cutting lubricant, especially if you are doing a lot of holes. Minimum drill pressure is best, let the bit do the work. If you have a drill press, that is the best way.
 
bruceb said:
I will also suggest a cobalt drill bit. They hold up very well. Also a slow drill speed is best and you should use a cutting lubricant, especially if you are doing a lot of holes. Minimum drill pressure is best, let the bit do the work. If you have a drill press, that is the best way.
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You want heavy pressure on the drill if it's a work hardening material.
 
You want enough feed pressure to see chips around the drill bit flutes. Too little and you will not be cutting. Too much and all you will end up doing is burning out the drill bit (it will get very hot and dull) after a few holes. Drill bit lubricant also plays an important role, especially in hard materials. The OP also asked about sharpening the the bits. The best tool for that, for a home shop is a device called the Drill Doctor ... they are not that costly and after some practice on old bits, your bits will work like new. http://www.drilldoctor.com/ ... They make a few models, and you can find one in your price range.

750.jpg
 
bruceb said:
You want enough feed pressure to see chips around the drill bit flutes. Too little and you will not be cutting. Too much and all you will end up doing is burning out the drill bit (it will get very hot and dull) after a few holes. Drill bit lubricant also plays an important role, especially in hard materials. The OP also asked about sharpening the the bits. The best tool for that, for a home shop is a device called the Drill Doctor ... they are not that costly and after some practice on old bits, your bits will work like new. http://www.drilldoctor.com/ ... They make a few models, and you can find one in your price range.

750.jpg
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thx!
but will this work for titanium coated bits? (underneath the coating is cheap potmetal??)
 
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