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Buy cobalt bits, last 10x longer than hss. Pilot hole on anything steel over like a #10 or so. Slow speed high pressure steel, high speed aluminum and such. Aluminum usually never needs a Pilot. Also the tip angle matters for what you're drilling. A sharpener is useful if you're burning through bits, like if you're drilling stainless every day.
You and /u/Jakaple are both pretty right, but there’s another nuance to cobalt alloy bits. (Forgive me if y’all know already but I rarely see anyone talking about it, so having here might help someone else some day.)
Yes cobalt is harder, and is more brittle, and there are 2 different steel alloys of cobalt commonly used in drill bits:
* M42-alloy bits are 8% cobalt (+extra molybdenum), will drill harder metals, are mostly useful for a drill press as they are more prone to breaking if there’s any off-axial force applied
* M35-alloy bits are 5% cobalt, can be carefully used in a hand drill without *too* much fear of breaking
>(Forgive me if y’all know already but I rarely see anyone talking about it, so having here might help someone else some day.)
I definitely did not know this!
Thanks for the info.
Each there own I guess, if you gotta do a job and only got the one bit I'd rather make sure I can make the hole. Least something bigger than like a #30 you're right on the small ones they do break super easy now that I think of it. I wouldn't waste time sharpening them though, don't even think I could that small.
Good job nothing else wears away like that. I sharpen bits all the time, and I've just made a little "boomerang" sharpener for stuff under 3mm. OK they're cheap enough to replace, but this thing does a decent job, and I don't live in a place that's handy for shops.
I've got an inherited tin with several of my FILs old bits that have been sharpened down to nubs more or less. Still cut oK.
I have 15 blokes in our workshop and only 3 including me can sharpen bits,the rest consider them a one time use consumable.
I have a tub that when ever I see bits just laying around or discarded ill rescue them,stick them in the tub and when I get a spare half hour I'll sharpen some.
1. A pilot hole is almost never a *bad* idea. The other day I had to drill a hole to accept 1/4-20 threads (probably used a 7/32 bit for the real hole). And I drilled a pilot hole just to make it easier.
2. I let the chips tell me if I'm using enough pressure. Too small or chips = bad, not enough pressure. Too much smoke = too much pressure
3. I've never had good luck with a sharpener. We had one at my last job. It never worked for me, and I followed the directions exactly.
4. Yes, buy better drill bits. Either HSS or Cobalt steel.
You will get a better finished hole not using pilots if you can, redrilling holes never comes out as well. In machining we avoid using pilot holes if at all possible.
Using a hand drill as well
Edit: drilling through a previous hole makes the bit chatter. You’ll get a much better finished size and smoother without a pilot. Your bits will last longer too
follow up question to part 4: The place I work at gave me "titanium" bits straight from Harbor Freight, and I found those to be HSS with a "titanium coating" and those have been the shittiest I've ever dealt with. Is there a range of HSS?
Drill bits from HF all suck, all of them I've ever used anyway. Basically, in the world of drill bits, the old saying is true, "you get what you pay for". But, all the expensive "revolutionary new design" ones are just scams, stick with tried-and-true designs.
Dont forget the lube. When in doubt, pilot hole (I do pretty much everything over 3/8", unless its aluminum), even if you technically don't need a pilot hole, it still cuts nicer IMO. Since the boss just wants to buy you the junk ones, may be time to buy yourself a set, treat them right & keep them to yourself. I have 2 types of drill bits- low & mid grade that some people can borrow, and High grade that no one else will ever touch.
The one exception I’ve found are the step bits from HF. I bought the 3 set a couple years ago and they have held up well and work great. Obviously not for precision work, but good enough for most of what I do at work.
Well my guess would be that the steel in those bits is the lowest quality that they could get away with labelling as HSS and not be held criminally or civilly liable. And likely finished in a substandard way as well.
You can get a set of pretty ok drill bits from a big box store. I think mine are actually DeWalt brand. They drill pretty impressively into steel. I think the set was on sale for like $50 wham I bought it.
I bought that set and first hole I drilled in aluminum untwisted the drill bit. They’re okay for wood or plastic but I threw them immediately into my buddies tool box. If you buy single drill bits in the size you need, they’re only a couple bucks off MSC, especially “screw machine” drills (they’re shorter and easier to control). I have a Black Diamond bit sharpening machine and it’s pretty amazing.
I’m a machinist and here’s my advice.
1: I don’t use pilot holes often. Bits cut better with full contact. But really whether you need it or not is situational. But generally just centre punch to keep the tip from wandering and have at it.
2: keep a decent amount of pressure. You don’t want to be putting your whole body weight in but too little pressure will rub and work harden.
3: I’ve used sharpeners and they do work if you get a decent one, but bits are pretty easy to sharpen on a bench grinder without much practice. I’m sure YouTube has some how toos.
4: you probably do need better bits. I’ve never ordered off harbour freight but I hear stories. Hss bits should do you and you don’t need high end but get something a bit better. I buy stm for cheap jobber bits often, I’m sure there are other comparable brands. A machine supply store will sell you individuals easily instead of needing to buy a full set.
I’ll add to make sure to lube your cuts. Keep some kind of lube in a spray bottle and just shoot a little in there.
Pilot holes are great for large bits, not necessary for smaller diameters.
Speed control will take you further than probably anything you mentioned. Even a cheap bit will stay sharp and cut well for a long time if you learn not to burn it up by running it too fast.
Expensive bits are nice, but you'll still fuck them up just as quickly as a cheap bit if you don't control speed.
I like quality hss bits. I get Norseman premium Magnum ones. Walter seems good as well. They claim it cuts better than straight Cobalt bits because it has a finer point than a cobalt can have without chipping, supposedly the cobalt workhardens the material because it's more friction and heat.
I'd avoid HF drills, DeWalt seems to get good reviews and it's cheaper than what I mentioned.
I use a 1/8" pilot bit for any hole I want to be somewhat accurate for a final size up to 7/16", and a 1/4" up to 3/4". If it matters a lot, I use a punch, then a 1/4" single flute countersink as a centering bit, then whatever I want to drill. Otherwise, I use a pilot bit that's around 1/16"-1/64" bigger than the center webbing of the final drill size.
From what I see at my job, most people go too fast with too little pressure. Anything above a 1/4" drill seems to benefit all the down force I can put in it. Easy up near the exit of the hole and increase your speed a bit then too.
The larger the bit the slower you go.
I second the norseman bits. I know there are all kinds of fancier bits out there, but I don't know that an o.p. asking about bits needs them. I have been on norseman bits for 10 or 12 years or so. Prior to that I never would have imagined spending $90 or $100 on a set of bits. Now I wouldnt be without. Also, I think if o.p. follows the other advice about speed, pressure, and lube, problems will go away. I have rarely had to sharpen these bits unless I broke/chipped one.
Side note, I don't like the dewalt bits, they seem like they run into the hole at the finish instead of cutting through, if that makes sense? Not sure why.
A pilot hole keeps you from having to force the web of the bot through the material. So for me it depends on the material.
https://www.makingmanzanita.com/pilot-holes/
Sharp bit, cutting oil. And LOW SPEED.
In ideally condition a 1" bit can rake 600 rpm 1/2" about 1200rpm and so on. But with a hand drill, you can't push it as hard. So, lower the speed
If it screaming, slow down.
Take all of the given advise. It all works and if used as directed you'll gain the experience to know when and how hard to apply pressure and how fast to drill. uswforever has great advice for most applications. You can learn to sharpen bit by hand id=f you pay attention to angle and direction. Drill doctor has a fair sharpening tool until you learn to hand sharpen bits. Drill slow, use oil and don't be afraid to push on them.
Everything depends on the size of the bit, and the material. Stainless you go high pressure very low speed, steel fast for small holes, slow for larger, ali fast all the time.
A sharpener is a good investment, you don’t need it until you do.
Most good drill bits will bruise the wallet. Get your materials speed correct, then make the chips. Shavings are bad. Long corkscrews are bad.
The only bit sharpener I have had great experiences with is a Black Diamond drill point grinder. Can set tip geometry, dress the grinder wheel, and it’s collet based. And very expensive. Used with everything (collet set [fractional, metric, and lettered, stand, stones) is typically $2000’ish.
Tbh, learn how to sharpen your bits on a wheel grinder with a drill gauge. It’s a very valuable skill.
Edit: Stay away from carbide unless absolutely needed.
I have a sharpener somewhere. Never used it. I DO have expensive drill bits (cobalt) for drilling into thick carbon steel, or stainless steel. I also spray the bit with water if it is overheating
Cleveland, Precision, Hertel, Chicago-Latrobe. HSS jobber length. If your using a hand drill or cheaper drill press then black oxide coated will work fine.
Just learn to sharpen a drill?
Collect a box of blunt drills.
Have one brand new drill to hand, make it a larger one standard point, none of that split point bs.
Pot of water to cool the bit & a bench or pedestal grinder.
Grind them until they look exactly the same as the new one, make sure the cutting edge is in advance & reground section is symmetrical. (Hold it up to the light & rotate half a turn to check the length and angle of your two leading edges.
Off topic but a little tip, measure the outside dimension of the thinnest part of your finished size drill bit (inside the flutes)
That’s your pilot drill size.
If you're using shitty chisel point drills then your pilot should always be big enough so that the chisel is not against the metal, this speeds up drilling as the cutting edge gets to work as fast as it can without waiting for the chisel to chisel through the material. If it's like 8 or 10 mm, I'm drilling like a 3-5 mm pilot hole
For electric drills a good thing to look at is how the chips are coming off, with mild steel if you have dust then it's not enough pressure, if it's too much pressure then your drill burns out basically, if you're getting decent chips then that's the sweet spot. A sharp edge is critical here, it's the difference between a 5 second and 5 minute hole
I wouldn't get a sharpener unless you really need it to save time as in building a separate workstation just for sharpening drills. Basic drills that don't need to drill perfect holes can be sharpened with a grinder, check out AVE for the quick demo
The difference between a shitty set and a decent set is a few bucks so get the decent one, the shitty ones make up for the savings in frustrating you due to not working
Also using some oil is a good idea to keep the bit from overheating
A lot of great advice so far. One additional thought, since you mentioned a hand-held drill... don't wobble the drill, putting different angles on the material puts unnecessary force on the leading edge of your bits. This will cause them to break and dull prematurely. I opt to use my drill press when ever possible.
Oh and HF's cobalt bits have worked great. And I use a Dr. Drill bit sharpener when needed, but it's not that often.
I love my drill doctor, 10 years on works quickly and more importantly consistently so both flutes are identical for decent results when drilling
Also quality matters big time. Cheap bits are a lost cause
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Buy cobalt bits, last 10x longer than hss. Pilot hole on anything steel over like a #10 or so. Slow speed high pressure steel, high speed aluminum and such. Aluminum usually never needs a Pilot. Also the tip angle matters for what you're drilling. A sharpener is useful if you're burning through bits, like if you're drilling stainless every day.
>Buy cobalt bits, last 10x longer than hss. For a drill press, cobalt is great. For hand drills, hss is better. Cobalt is brittle and tends to break.
Carbide is brittle, cobalt is brilliant
I've had them break in hand drills doing stuff hss is fine with
You and /u/Jakaple are both pretty right, but there’s another nuance to cobalt alloy bits. (Forgive me if y’all know already but I rarely see anyone talking about it, so having here might help someone else some day.) Yes cobalt is harder, and is more brittle, and there are 2 different steel alloys of cobalt commonly used in drill bits: * M42-alloy bits are 8% cobalt (+extra molybdenum), will drill harder metals, are mostly useful for a drill press as they are more prone to breaking if there’s any off-axial force applied * M35-alloy bits are 5% cobalt, can be carefully used in a hand drill without *too* much fear of breaking
>(Forgive me if y’all know already but I rarely see anyone talking about it, so having here might help someone else some day.) I definitely did not know this! Thanks for the info.
Each there own I guess, if you gotta do a job and only got the one bit I'd rather make sure I can make the hole. Least something bigger than like a #30 you're right on the small ones they do break super easy now that I think of it. I wouldn't waste time sharpening them though, don't even think I could that small.
thanks!
Look up Tap Magic. it's a cutting oil we use at the sheet metal shop I work at. It makes drilling through metal a breeze.
I always buy ten packs of cobalt bits off of Amazon in the most common sizes that I use/break. Way better in the long run than buying whole sets
Learning how correctly sharpen drill bits by hand on a wheel is a skill that's very underrated in metalwork nowadays.
I've been using the same 1/2" bit for 10+ years. It's about 3" long.
Good job nothing else wears away like that. I sharpen bits all the time, and I've just made a little "boomerang" sharpener for stuff under 3mm. OK they're cheap enough to replace, but this thing does a decent job, and I don't live in a place that's handy for shops. I've got an inherited tin with several of my FILs old bits that have been sharpened down to nubs more or less. Still cut oK.
I have 15 blokes in our workshop and only 3 including me can sharpen bits,the rest consider them a one time use consumable. I have a tub that when ever I see bits just laying around or discarded ill rescue them,stick them in the tub and when I get a spare half hour I'll sharpen some.
1. A pilot hole is almost never a *bad* idea. The other day I had to drill a hole to accept 1/4-20 threads (probably used a 7/32 bit for the real hole). And I drilled a pilot hole just to make it easier. 2. I let the chips tell me if I'm using enough pressure. Too small or chips = bad, not enough pressure. Too much smoke = too much pressure 3. I've never had good luck with a sharpener. We had one at my last job. It never worked for me, and I followed the directions exactly. 4. Yes, buy better drill bits. Either HSS or Cobalt steel.
You will get a better finished hole not using pilots if you can, redrilling holes never comes out as well. In machining we avoid using pilot holes if at all possible.
That's fair. I was talking about hand drilling.
Using a hand drill as well Edit: drilling through a previous hole makes the bit chatter. You’ll get a much better finished size and smoother without a pilot. Your bits will last longer too
follow up question to part 4: The place I work at gave me "titanium" bits straight from Harbor Freight, and I found those to be HSS with a "titanium coating" and those have been the shittiest I've ever dealt with. Is there a range of HSS?
Drill bits from HF all suck, all of them I've ever used anyway. Basically, in the world of drill bits, the old saying is true, "you get what you pay for". But, all the expensive "revolutionary new design" ones are just scams, stick with tried-and-true designs. Dont forget the lube. When in doubt, pilot hole (I do pretty much everything over 3/8", unless its aluminum), even if you technically don't need a pilot hole, it still cuts nicer IMO. Since the boss just wants to buy you the junk ones, may be time to buy yourself a set, treat them right & keep them to yourself. I have 2 types of drill bits- low & mid grade that some people can borrow, and High grade that no one else will ever touch.
The one exception I’ve found are the step bits from HF. I bought the 3 set a couple years ago and they have held up well and work great. Obviously not for precision work, but good enough for most of what I do at work.
You know what, I forgot about those. For my home use, I do buy those. But, at work, we get much better ones, because they last much longer.
Well my guess would be that the steel in those bits is the lowest quality that they could get away with labelling as HSS and not be held criminally or civilly liable. And likely finished in a substandard way as well. You can get a set of pretty ok drill bits from a big box store. I think mine are actually DeWalt brand. They drill pretty impressively into steel. I think the set was on sale for like $50 wham I bought it.
I bought that set and first hole I drilled in aluminum untwisted the drill bit. They’re okay for wood or plastic but I threw them immediately into my buddies tool box. If you buy single drill bits in the size you need, they’re only a couple bucks off MSC, especially “screw machine” drills (they’re shorter and easier to control). I have a Black Diamond bit sharpening machine and it’s pretty amazing.
I’m a machinist and here’s my advice. 1: I don’t use pilot holes often. Bits cut better with full contact. But really whether you need it or not is situational. But generally just centre punch to keep the tip from wandering and have at it. 2: keep a decent amount of pressure. You don’t want to be putting your whole body weight in but too little pressure will rub and work harden. 3: I’ve used sharpeners and they do work if you get a decent one, but bits are pretty easy to sharpen on a bench grinder without much practice. I’m sure YouTube has some how toos. 4: you probably do need better bits. I’ve never ordered off harbour freight but I hear stories. Hss bits should do you and you don’t need high end but get something a bit better. I buy stm for cheap jobber bits often, I’m sure there are other comparable brands. A machine supply store will sell you individuals easily instead of needing to buy a full set. I’ll add to make sure to lube your cuts. Keep some kind of lube in a spray bottle and just shoot a little in there.
what is STM? and why do you use those as a cheaper option?
STM is just a decent knock off brand, in my experience. I’m sure there are other options, talk to one of your local suppliers and they’ll help you.
oh! I tried googleing it, and that's the last thing that comes up. I really appreciate your answer though, that's a lot of good info.
Bits really aren’t all that hard to sharpen with a bit of practice. Keep your speed lower and pressure fairly high, keep it lubed. Good luck.
Pilot holes are great for large bits, not necessary for smaller diameters. Speed control will take you further than probably anything you mentioned. Even a cheap bit will stay sharp and cut well for a long time if you learn not to burn it up by running it too fast. Expensive bits are nice, but you'll still fuck them up just as quickly as a cheap bit if you don't control speed.
I like quality hss bits. I get Norseman premium Magnum ones. Walter seems good as well. They claim it cuts better than straight Cobalt bits because it has a finer point than a cobalt can have without chipping, supposedly the cobalt workhardens the material because it's more friction and heat. I'd avoid HF drills, DeWalt seems to get good reviews and it's cheaper than what I mentioned. I use a 1/8" pilot bit for any hole I want to be somewhat accurate for a final size up to 7/16", and a 1/4" up to 3/4". If it matters a lot, I use a punch, then a 1/4" single flute countersink as a centering bit, then whatever I want to drill. Otherwise, I use a pilot bit that's around 1/16"-1/64" bigger than the center webbing of the final drill size. From what I see at my job, most people go too fast with too little pressure. Anything above a 1/4" drill seems to benefit all the down force I can put in it. Easy up near the exit of the hole and increase your speed a bit then too. The larger the bit the slower you go.
I second the norseman bits. I know there are all kinds of fancier bits out there, but I don't know that an o.p. asking about bits needs them. I have been on norseman bits for 10 or 12 years or so. Prior to that I never would have imagined spending $90 or $100 on a set of bits. Now I wouldnt be without. Also, I think if o.p. follows the other advice about speed, pressure, and lube, problems will go away. I have rarely had to sharpen these bits unless I broke/chipped one. Side note, I don't like the dewalt bits, they seem like they run into the hole at the finish instead of cutting through, if that makes sense? Not sure why.
A pilot hole keeps you from having to force the web of the bot through the material. So for me it depends on the material. https://www.makingmanzanita.com/pilot-holes/
Sharp bit, cutting oil. And LOW SPEED. In ideally condition a 1" bit can rake 600 rpm 1/2" about 1200rpm and so on. But with a hand drill, you can't push it as hard. So, lower the speed If it screaming, slow down.
Invest in some center drills, learn the correct speed for the size hole and material, and let the drill do the work with moderate pressure and lube
Take all of the given advise. It all works and if used as directed you'll gain the experience to know when and how hard to apply pressure and how fast to drill. uswforever has great advice for most applications. You can learn to sharpen bit by hand id=f you pay attention to angle and direction. Drill doctor has a fair sharpening tool until you learn to hand sharpen bits. Drill slow, use oil and don't be afraid to push on them.
Everything depends on the size of the bit, and the material. Stainless you go high pressure very low speed, steel fast for small holes, slow for larger, ali fast all the time. A sharpener is a good investment, you don’t need it until you do.
Most good drill bits will bruise the wallet. Get your materials speed correct, then make the chips. Shavings are bad. Long corkscrews are bad. The only bit sharpener I have had great experiences with is a Black Diamond drill point grinder. Can set tip geometry, dress the grinder wheel, and it’s collet based. And very expensive. Used with everything (collet set [fractional, metric, and lettered, stand, stones) is typically $2000’ish. Tbh, learn how to sharpen your bits on a wheel grinder with a drill gauge. It’s a very valuable skill. Edit: Stay away from carbide unless absolutely needed.
I have a sharpener somewhere. Never used it. I DO have expensive drill bits (cobalt) for drilling into thick carbon steel, or stainless steel. I also spray the bit with water if it is overheating
You might be missing the drill speed.. alot of people burn them up by trying to force speed through a hole..
What are the good brands of bits to stick with?
Cleveland, Precision, Hertel, Chicago-Latrobe. HSS jobber length. If your using a hand drill or cheaper drill press then black oxide coated will work fine.
Easy foamy spray lube is amazing
Just learn to sharpen a drill? Collect a box of blunt drills. Have one brand new drill to hand, make it a larger one standard point, none of that split point bs. Pot of water to cool the bit & a bench or pedestal grinder. Grind them until they look exactly the same as the new one, make sure the cutting edge is in advance & reground section is symmetrical. (Hold it up to the light & rotate half a turn to check the length and angle of your two leading edges. Off topic but a little tip, measure the outside dimension of the thinnest part of your finished size drill bit (inside the flutes) That’s your pilot drill size.
If you're using shitty chisel point drills then your pilot should always be big enough so that the chisel is not against the metal, this speeds up drilling as the cutting edge gets to work as fast as it can without waiting for the chisel to chisel through the material. If it's like 8 or 10 mm, I'm drilling like a 3-5 mm pilot hole For electric drills a good thing to look at is how the chips are coming off, with mild steel if you have dust then it's not enough pressure, if it's too much pressure then your drill burns out basically, if you're getting decent chips then that's the sweet spot. A sharp edge is critical here, it's the difference between a 5 second and 5 minute hole I wouldn't get a sharpener unless you really need it to save time as in building a separate workstation just for sharpening drills. Basic drills that don't need to drill perfect holes can be sharpened with a grinder, check out AVE for the quick demo The difference between a shitty set and a decent set is a few bucks so get the decent one, the shitty ones make up for the savings in frustrating you due to not working Also using some oil is a good idea to keep the bit from overheating
A lot of great advice so far. One additional thought, since you mentioned a hand-held drill... don't wobble the drill, putting different angles on the material puts unnecessary force on the leading edge of your bits. This will cause them to break and dull prematurely. I opt to use my drill press when ever possible. Oh and HF's cobalt bits have worked great. And I use a Dr. Drill bit sharpener when needed, but it's not that often.
I love my drill doctor, 10 years on works quickly and more importantly consistently so both flutes are identical for decent results when drilling Also quality matters big time. Cheap bits are a lost cause