Hey Drill Bit Manufacturers, Would It Kill You To....
- Thread starter jonshonda
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quickfarms
Well-known member
The problem is that the machine that does the stamping was designed by a group of engineers that have never used a drill bit and it would cost millions to change the assembly line and machinery
scooby074
Well-known member
I have several old drills that had actual stamping in a bare area above the flutes, but below the shank area where the chuck would ride. Now its all laser etched and it *****. Even on good drills. I just keep everything in an index anyways.
...engineers that have never used a drill bit... You forgot to type the / character at the end of your comment.
FrankLee
Well-known member
purplezr2
Well-known member
I'm an engineer, and I have also wondered why they stamp them in the location they do.
I really like the bits with three flats, no spinning that way.
I really like the bits with three flats, no spinning that way.
What percentage of the time does the chuck grab at the correct spot (on the flats) for you? Mine seems to be about 1/4 times it needs adjustment!
cmandp
Well-known member
I'm sure the reason for the location is more for manufacturing and not design. It's probably more difficult to mark higher up from a work holding perspective.
I don't like the bits with flats. They don't chuck as concentrically as a standard round shank. Doesn't really matter in a hand held drill or maybe even a drill press. But the machinist in me can't get over it
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I don't like the bits with flats. They don't chuck as concentrically as a standard round shank. Doesn't really matter in a hand held drill or maybe even a drill press. But the machinist in me can't get over it
.dr_clyde
Well-known member
I would say that if you're using twist drills in a cordless drill chuck, you should buy a set of mechanic's length drills. These have the three flats on them and are designed for use in a cordless drill. Hand drilling holes is inherently prone to runout and crooked holes anyway, the loss of concentricity from the flats is negligible.
Most other applications that hold drills tend not to slip and this isn't a problem. I can't remember the last time I had drills slip in my keyed Jacob's chucks or the keyless Albrecht chucks on the drill press or in the ER collet chucks on the CNC. And I would wager that the vast majority of twist drill users are industrial users, not cordless drill applications.
Most other applications that hold drills tend not to slip and this isn't a problem. I can't remember the last time I had drills slip in my keyed Jacob's chucks or the keyless Albrecht chucks on the drill press or in the ER collet chucks on the CNC. And I would wager that the vast majority of twist drill users are industrial users, not cordless drill applications.
American Locomotive
Well-known member
While it is a bit unfortunate they always stamp the size there, if you have a good drill chuck it's not really an issue. On my Makita, the drill will stall well before it ever slips.
The old Milwaukee M18 drill I used to have at work? Forget it. That thing would slip with a piece of hex-stock chucked in it.
The old Milwaukee M18 drill I used to have at work? Forget it. That thing would slip with a piece of hex-stock chucked in it.
Astro_Pneumatic_Tools
Well-known member
Drill bits are differentially heat treated so that the cutting end and the flutes are hard and the shank, well yeah that's hard too but not AS hard. This is for better chuck grip and for allowing roll stamping.
The problem is, the closer you get to the flutes the harder the material. It's not a huge differential, but enough that roll stamping becomes impossible. (think about the act of stamping and leaving an indented shape and how that might become more difficult on material harder than a tooling die or just willing to shatter from pressure).
This can be compounded by 2 things.
1 material. Lower grades of HSS don't mind as their peak toughness is at a lower hardness, heck some you could probably stamp the flutes.
On Cobalt you sometimes have to go down even further if you want to it readable in any effective way.
2 dill bit length. We're making jobber length which is pretty standard. Mechanic's length, and especially in cobalt, causes roll stamping tooling to last about 1/10th the life and has to be a smidge lower on the shank unless you want sub-optimal drill bit heat-treat.
We're working on stubby length now and we can't even get a stamp on any part of the shank on cobalt versions. Regrettably we have to move to 100% laser etch for those.
TLDR: We're not a$$holes (well, some of us are but anyways..), it's like designing anything. There's gives and takes. And as far as engineers never working with drill bits. That's a laugh, I would venture to guess I'm at over 100,000 holes now. I can't do laundry without finding steel curly ques everywhere.
The problem is, the closer you get to the flutes the harder the material. It's not a huge differential, but enough that roll stamping becomes impossible. (think about the act of stamping and leaving an indented shape and how that might become more difficult on material harder than a tooling die or just willing to shatter from pressure).
This can be compounded by 2 things.
1 material. Lower grades of HSS don't mind as their peak toughness is at a lower hardness, heck some you could probably stamp the flutes.
On Cobalt you sometimes have to go down even further if you want to it readable in any effective way.
2 dill bit length. We're making jobber length which is pretty standard. Mechanic's length, and especially in cobalt, causes roll stamping tooling to last about 1/10th the life and has to be a smidge lower on the shank unless you want sub-optimal drill bit heat-treat.
We're working on stubby length now and we can't even get a stamp on any part of the shank on cobalt versions. Regrettably we have to move to 100% laser etch for those.
TLDR: We're not a$$holes (well, some of us are but anyways..), it's like designing anything. There's gives and takes. And as far as engineers never working with drill bits. That's a laugh, I would venture to guess I'm at over 100,000 holes now. I can't do laundry without finding steel curly ques everywhere.
thank you for the explanation. Question, though, why not stamp the size first, before heat treat?
Astro_Pneumatic_Tools
Well-known member
Drill bits are not heat treated after forming into a drill bit. They are precision ground after heat treat to their final size, otherwise the final size would not be accurate and you'd risk warping (causing run-out or wobbling) or chips from handing or cracks. Which is why it's so costly to make good drill bits, takes awhile to grind into hardened M2 or cobalt.
That's not to say that there aren't some processes done to drill bits after with a wide range of options. But for the most part the material is incredibly hard when brought to the machine shop floor.
ddawg16
Well-known member
I'd rather the drill bit slip a little vs breaking......or breaking my wrist
Walkers
Well-known member
Power the chuck closed to a point smaller than the drill, the reverse the drill and power open until the drill slides in to the chuck and tighten.
Firebrick43
Well-known member
every time. You need to set there and wiggle it as you tighten the chuck so it sets perpendicular to the flat. As for the stamping being torn up, good chucks don't slip. Replace it with a good rohm.
If you have a milwaukee cordless, the chuck is only good to "put in a sock and beat your stupid coworkers with" as I saw it written once. Rohm makes an appropriate threaded chuck for it
Walkers
Well-known member
I have fraction drills, numbered drills, lettered drills, metric drills. Often they are so close it is difficult to tell them apart with a plate gauge. If they didn’t have a different appearance due to different manufacturers it would be hard to get them put away sometimes.
My most commonly used drills all have some scarring on the shank. They usually get replaced once a year or so. I always have calipers around if I am unsure, or need to find a specific size in the box of used spares. I have a loupe in the toolbox to read the sizes if they have them. For anything over 3/16“ or so an end stamp would be ideal.
My most commonly used drills all have some scarring on the shank. They usually get replaced once a year or so. I always have calipers around if I am unsure, or need to find a specific size in the box of used spares. I have a loupe in the toolbox to read the sizes if they have them. For anything over 3/16“ or so an end stamp would be ideal.
That makes perfect sense. Thank you for the clear explanation (and also for making nice tools!)
Thanks for the info ASTRO! I know stamping is difficult, but technology should have eliminated the need for stamping many moons ago I would have thought. Like laser etching in the valley of the flute close to he shank? Idk
But as others have said, hand drilling isn't very accurate so it's not like I desire the precision, just want to know what I am working with!
And I guess I wasn't aware that milwaukee chucks sucked donkey d!ck, but that explains my frustration and chewed up bits.
But as others have said, hand drilling isn't very accurate so it's not like I desire the precision, just want to know what I am working with!
And I guess I wasn't aware that milwaukee chucks sucked donkey d!ck, but that explains my frustration and chewed up bits.
dnschmidt
Well-known member
OK Chris, when do we get the good Astro drill bits? Sign me up for some cobalts.
Put me in this category. If a bit is in question then the calipers come out. I end up with a lot of used bits and once in a while I set up a session at the drill bit sharpener and sharpen, then measure to determine the size. Once the size is determined the bit is put put in the proper place whether it be an index or drawer. If you understand that drill bits are not for making precision holes then life becomes easier.
One poster on another forum determined that there may be near 10,000 different drill bits for making holes under 1/2" in diameter.
lg
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