I'm trying to drill my steering arms so that I can mount my disk brakes on my dodge. I've gone through 2 blu-mole bits already and they suck. Dewalt doesn't seem to make metal bits larger than 1/2". Where can I find/order what ever a good drill bit.
What are you doing to ruin two drill bits so far ? Running too fast ? No coolant ? What not resharpen the ones you have ? If you want decent drills,try www.travers.com
I have the drill set to the slowest setting and I am using cuting oil to keep things cool. I have tried sharpening the first bit I killed but I'm just going to get a refund on te second one and but another bit from somewhere else. Any one else have issues with Blu-mole bit's before?
are you trying to drill or just open up an already established hole to 5/8"? if its just opening up a hole youd be best off getting a reamer. if you are trying to drill a hole dont use any more of a pilot than what the this point of the drill is, maybe just a hair more, probably around 3/16" in your case. it could be to that your arms are forged steel, which if thats the case all bets are off. if it has become "work-hardened" (youll know because of heat marks around the hole) then hit it first with a 5/8" masonry bit just enough to get it through the hard spot. then go in the rest of the way with a conventional drill. the best drill alloys have cobalt. the more cobalt the more expensive, but 8% cobalt is pretty good. in the least you need high speed steel. try to keep some cutting oil on it too. ace/true value/rigid brand pipe threading oil (also excellent for honing)goes a long way but stinks. some good sights for quality drills/cutting tools are : www.mscdirect.com www.jlindustrial.com just do searches for what youre looking for. hope this helps.
I bought cobalt bits at Sears. Well worth the money. They might not have 5/8ths on the rack though. I know they have 1/2"
f you are going straight at it with a 5/8 and say the hole is orig a 7/16 it will kill every 5/8 you throw at it. You have to use the drill bits in progressive order. Start with the next size from the hole that is there and work upward using every size in between. You can also try a unibit which basically does the same. I prefer regular bits. Obviously this is besides the above advise on lubricants and such. You will be surprised how much easier it becomes instead of tearing up the tip of bits.
Sutton Tools bits hold out pretty well, we use them to drill chassis rails on heavy trucks all day long at work. we generally pilot in steps of 3/16" - 5/16" - 1/2" - 5/8". going from 9/16" - 5/8" is hard going for the bits but can be done. if its tough, you are going to need a reamer. reamers are less likely to grab and rip the drill out of your hands, though im guessing you'd be using a press for this job. we use Wurth cutting oil but im guessing its all pretty much the same stuff, but at least the wurth stuff doesnt stink like dog shit!
WRONG ! I've drilled 1"+ holes with a 1/4" or smaller pilot hole,in steel, no problems.Just a matter of having access to the right equipment,and knowing how to use it.
Sure, you CAN do that, but for those of us who don't wanna blow a fortune on the 'right equipment' to do something we don't do that often, working your way up is fine. Shit, I use a costco drill bit set that I gave $40 for a couple hundred bits and I've drilled holes that big in well over an inch thick material. The other thing you might wanna consider is that if you're using a drill press intended for wood, the lowest speed might not be very low. Mine's not, but I make up for it by drilling lots of holes. I seriously think that even with the bit changing, working your way up is actually faster. At least it is with my limited setup...
I had the luck of watching a sharp machinist's mate sharpen a drill bit on a bench grinder stone in the USN. I can't do it as well as he could but I can sharpen an otherwise trashed bit.
If the drill is burning or wearing on the outside of the cutting edge at what is called the margin or land you are going too fast for the materiel being drilled or your cutting oil is not right . The old cutting oils that had sulfur added were best as sulfur goes to the heat. The earlier post that said drill first with smaller drill is right, your first drill size should be no larger than the width of the point otherwise the larger drill will chatter and your hole won't be round.
That is a good way to ruin your drills. It will chip off the web on the outer cutting edge, and on split point drills, with chip on the split point. A pilot hole should be large enough to clear the split point, and small enough to be far from the outer web. There is a formula for this (I forget it), but if the size of the pilot hole drill's outer diameter falls around the center of the cutting edge on the larger drill (halfway between the outer web, and the split point) you should be ok, and not ruin the drill. Also, GO SLOW, heat is your enemy, and most people dont drill slow enough. You should use slow speeds, a good amount of cutting oil, and firm pressure. The chips should come off in fairly large "shavings" of metal, or a light spiral in the very early stage of the hole. If the chips are hot, thats fine, they are carrying the heat of the cut, and keeping it off of the drill. If no chips are being produced, and the drill is just spinning, STOP. All you are doing is building up heat, and in effect, annealing the cutting edge of the drill. If no cutting is taking place, you have a dull edge, and its often caused by past abuse. High speeds/high heat buildup soften the cutting edge, and it will go dull very fast. Cheap drills also are not made of the same quality steel, and are not heat treated the same as a high end drill. Also, Cobalt is ok for a drill press (a good solid press with a rigid setup, not a cheap one with lots of runout, and poorly secured work pieces), but its harder, and much more brittle than HHS, and with a hand drill, with chip much more easily, especialy with abuse (like enlarging holes). A good set of HHS bits should run around $100 -150 for a 29 piece 1/16-1/2" set (I know you need larger than that, but just a price reference). A cheap set of HSS drill is a waste of money (as is a cheap set of cobalts), they dont last very long. A good high end set of HSS drills, that is PROPERLY used should last for years, a cheap chinese set will last a few months. You cannot buy good quality drill sets (or individuals) at Home Depot (Or lowes, tractor supply, sears, etc.) Go to an industrial supply. Grainger, Enco, MSC, etc all sell drills from Triumph, Chicago Litrobe, Precision Twist, etc. Also check out Champion and Norseman. I have a 29 piece Norseman set, and 2 eqivalent Champion sets, and the Norsemans are really good. Check out the 29 piece Norseman mechanics length set. They are shorter (better clearance and less chance of breakage) than Jobber length, and also have 3 flats ground on the shank, they are the best size for a hand drill. Check out one of the drill manufacturers above, they are all USA made drills from companies with decades of experience, you cant go wrong. Treat them with the proper care, and they will last a long long time, and perform better than the Asian made junk sold at home stores.
i have a set i bought at industrial metal supply (american made cobalt) they were pricy but they have outlasted every drill bit i have ever bought by 100 times. so the cost seems to be worth it. i never drill a pilot hole and always use a drill press. lots of cutting oil and pressure make the best holes for me. if your piece is work hardened just heat and cool it slowly, it will anneal the piece and let you drill it easier.
Ahhh the voice of reason!! Thanks Ian! Some of you guys giving advice should take some notes here. You CAN drill BIG holes so long as you got the HP and SPEED (or lack there of) to do it. Most home type drill presses (and hand drills) run ENTIRELY TOO FAST to drill much bigger than a 3/8" hole. They are also normally WAY UNDERPOWERED. When you have these hurdles you have to learn to fudge things a little. What I do is learn to lean on that sucker hard enough to SLOW it down to a more resoanable speed. There will be a sweet spot between how much load you put on the tool and how fast you can run it. The next thing is to take as big a cut as practical - in some cases this will be rather small. I've read the posts that say you can't cut 1/32" step when drilling - HOG WASH. The problem when you do this is that you're drilling so little that it is EASY to push TOO HARD - you're basically drilling a 1/16" hole (bear with me) in terms of cut - so you gotta treat it like that - now add in the fact that you are cutting at a rate that is pretty fast for your diameter nd pretty soon you'll smoke the bit - resulting in you swearing it can't be done. The dril bit knows nothing - other than speed, feed, d.o.c - you can't lean on a 1/2 drill bit the same way if you're cutting 1/4" versus a 1/16". Lok at your chips - if they're BLUE - you're pushing the limits way too far and you're gonna smoke it in short order. Once you smoke it you often kill the heat treat so that when you resharpen it - it smokes instantly no matter how you correct your approach. When you sharpen them - you need to keep them relatively cool. Annealing them is bad mojo. The next problem when smokining bits is possibly hardening the material - not a problem so much with mild steel, but can be a mojor problem with others. Stainless is a good one for that - it'll work harden on you and reward you with misery. The solution is keeping the bit sharp to begin with. When it starts to dull STOP!!!!!! Don't force it - you'll only make matters worse. To the origional question - just get one made in the USA - nothing worse than fighting with crap bits to begin with.
I don't use drills on anything larger than 3/8" Mcmaster has a 7pc set of holecutters(rotobroach) around 65 bucks. drill a 1/8 pilot hole than use the hole cutter. It cuts a totally clean burr free hole. You can drill a 3/4 hole in frame stock in 30 seconds. You some coolant lube. Large drill bits suck
I can drill em all day long and not use a pilot hole or go progressive.. But ive been the tool business since i was 13.. Im 55 now.. Im just chuckling at the replies and im not gonna give an answer.. Good Luck Dave
How about taking the steering arms to a local machine shop and let them ruin their bits on them? Might wind up being cheaper in the long run.
Well then, it's really too bad we can't learn from your vast pool of knowledge. Glad we could enertain you though.
Calculate the proper rpm,the formula is in any decent machine shop text book,along with cutting speeds for different materials. In this case: (Cutting speed x 4) divided by the diameter = rpm. (50 x 4) / .625 = rpm 200 / .625 = 320 rpm By over heating the drill bits,you might have created a localized hard spot. SOMETIMES you can drill through them from the other side. Worst case,you would need a Carbide drill bit. Carbide tipped Concrete drills are a lot less money, but are usually oversize.And they don't last as long as a real carbide drill.
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