drill bit sharpening

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Hi. Its been a while since Ive been here. Ive had no pc for a while. Anyway, has anyone got some tips on sharpening drill bits. Im drilling 1/2 inch holes in a stainless beer keg. I get one hole done and then the bit wants to burn up. Im thinking it could be the angle im sharpening them on. Thanks
Reply:get the drill doctor for sharpening your bits. best money my wife ever spent on tools.  i can sharpen thebig bits by eye but those smaller ones are a pain.G3miller... 225g, s32p, 250x, 304, 12vs, MSW41     victor o/a thermal dynamics cutmaster 50 lenco panel spotter        hobart hf-boxG3 Farms.....raising cattle, hay, kids and hell, ...oh yeah I'm a fire sprinkler contractor by trade.
Reply:I agree, best tool my wife ever bought me also. Drill bit need to be sharpened on 2 angles at the same time, my luck was always hit and miss when I tried.If you don't want to stand behind our Troops, feel free to stand in front of them.
Reply:Stainless is more difficult to machine than regular steels; as you already have found out.  It tends to smear and gall, rather than cut producing a nice chip.  Here's some suggestions, based on my work with machinists:1 - Agree with everyone else here.  Sharpen your drill bits.  If you're doing this by hand, put a steeper rake on the cutting edge than you would for cutting plain carbon steel.  If you can buy carbide drill bits, they may work better for this job...2 - Use cutting fluid, if you're not already.  Heat buildup in the stainless steel and the drill tip is bad.  It makes the steel tougher to cut, and softens the steel in the drill bit.3 - Drill a succession of larger holes, don't start with a half inch bit.  For a half inch diameter hole, I'd drill an eighth inch pilot, step up to a quarter inch, and then finish with the half inch bit.4 - If you can, use slower speed with the larger diameter bits.  This will help keep the heat down.5 - Use more pressure along with slower speeds.  This, along with the steeper rake angle on the tool will help 'gouge' out larger chips, rather than smearing the stainless steel and work-hardening it.  It's a fine line between using enough pressure and snapping your smaller drill bits, so be careful.Good luck,Dave Originally Posted by juiceHi. Its been a while since Ive been here. Ive had no pc for a while. Anyway, has anyone got some tips on sharpening drill bits. Im drilling 1/2 inch holes in a stainless beer keg. I get one hole done and then the bit wants to burn up. Im thinking it could be the angle im sharpening them on. Thanks
Reply:Drill Doctors are awesome.I have had one for over a year and it's saved me a lot on drill bits. Great machine to have.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:Juice, try a "Unibit" step drill on your beer keg, they are absolutely the best thing for this application.  I have made several brew kettles out of used kegs and a hole saw is way better than any twist drill, but a uni-bit is better than the hole saw.http://www.weldingweb.com/vbb/showthread...ling+stainlessHoppy holidays and happy new beer.
Reply:Cobalt Drills bit are what you need for SS.oh and Drill Dr's are Ace.
Reply:you can get drill DR. at LOWEShttp://www.drilldoctor.com/pilot.aspLast edited by WANNAWELD; 01-03-2008 at 03:15 PM.
Reply:Thanx everyone. I have a drill sharpener but it will only sharpen up to 3/8. So the rest of my sharpening on larger bits has to be done on the grinder.Dave. you said to put a steeper rake on the cutting edge. At what angle would you say would be ok? I have destroyed my 1/2 drill bit so I am going to buy one today. I have used carbide bits for drilling masonry before, I didnt know they where available in normal twist drills.Also what are cobalt drill bits shox dr? I havent heard of them. Thanx for all your replies. I love this site. Great to see people are willing to lend a hand with their skills.
Reply:The drill doctor I have has three different rake settings. It also does the split bit sharpening which is a great thing to have. Also mine does up to 3/4 inch. Well worth the money.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:Different Metal drills and their applications Drill-bit Type  Comments High Speed Steel (HSS) Twist Bits: Designed for metal and most plastics, these bits work reasonably well in wood, and if you are on a budget, these are the ones to buy. Most metals and plastics form swarf well, (swarf is the curl of metal or plastic that spirals off during machining) and this travel up the flutes (the helical grooves up the side) of the drill-bit fairly freely. Wood, on the other hand forms sawdust, and this tends to "choke" the drill. Hence, it is necessary to use a pumping action with these drill-bits in wood. This is particularly important with the smaller sizes as not only are they easier to snap, but more inclined to choke. If you are drilling metal, the swarf may be very sharp, and the hole edges may be too, so watch your fingers. Drilled holes in metal should have the sharp edges deburred using a larger hand-held drill-bit or a special deburring tool.  Coated HSS Drills For those of you intending to do a lot of metal drilling, drill-bits coated with Titanium Aluminium Nitride (TiAlN) can be a worthwhile investment. This is a golden colour (but beware, some of the super-cheap ones are simply flash-plated gold, or even painted gold!) The coating is applied by vapour deposition and is hard, tough and has a low coefficient of friction. Normally high speed steel drill-bits do not drill aluminium gracefully (it tends to weld itself to the drill-bit, resulting in poor swarf clearance and a badly toleranced hole, either oversize, out-of-round or both). With TiAlN the low coefficient of friction eliminates this, and most metals can be drilled without coolant/lubricant. On top of this, faster cutting speeds can be employed and the tool life is about 10 times that of HSS. Obviously the price is higher, but industry seems to find it cost-effective, including less interruption for changing the bit.  Cobalt Drill-bits Another variation on the metal drilling theme. Cobalt drill-bits are the next step up the hardness scale from HSS drill-bits. They are designed to drill very hard materials, and will cope better with metals like stainless steel (although will still be blunted by some types). One useful DIY application is drilling out the remains of other broken drill-bits, although other harder bits may be better still.  C1150 The next harder step up is called a C1150. This has short flutes and a longer shank than normal. After this in hardness comes a D200 twist drill-bit. D200 This looks quite a lot like a HSS twist drill-bit, so you have to look at the packet it comes in. It is quite a good drill-bit to have for stainless steel. Solid Carbide Drill-bit  Now this is a beast. It will drill and cut into a screw and stud extractor (also known as an "easy out") — an extractor tool for a broken stud/bolt, and these are made from quite hard steel in their own right. There is also a fair chance that it could cut into any of the above drill-bits, if you could keep it on centre.
Reply:Literally just bought one at my local Lowes.  I'd thought about it for along time, and after the numerous recommendations in this topic, decided to spend the money.I figure I could spend 8 or 10 hours sharpening bits.  I inherited a whole box of old bits along with my drill press.  Many seem to be the same size, which makes me think they're all dull.   I paid $50 for the basic drill doctor.  There was a 'pro' model that was $100.  I couldn't see any differences from the info on the packaging.  They both would sharpen bits 3/32" to 1/2".  I'm wondering now if the pro version is the one that lets you set the rake angle....? Originally Posted by WANNAWELDyou can get drill DR. at LOWEShttp://www.drilldoctor.com/pilot.asp
Reply:I can't tell you exactly what angle will work.  Maybe a real machinist here can suggest the correct answer, or you might find it in a copy of a book like The Machinery Handbook.  You might also take a shot at emailing somebody at a drill manufacturer or machinery sales company...Anybody have any better ideas? Originally Posted by juiceDave. you said to put a steeper rake on the cutting edge. At what angle would you say would be ok?
Reply:cobalt drills are harder/tougher than HSS bits- typically they allow the use of higher speeds.they are useful but not necessary for stainless- HSS will work fine PROVIDED they are sharp, a positive feed is maintained (allow the drill to abrade and the SS will rapidly work harden wrecking the drill and making it harder to finish the hole) and the area is kept cool enough that the chips do not 'colour' high drill rpm and stainless do not go together- recommended drilling speed for ss is 30sfm (around 250 rpm for 1/2" bit) with HSS.135-140 degrees is a common tip angle for stainless but sharpness/drilling technique is more importantmake sure when sharpening that the 'relief angle' is maintained- lose this and the drill will overheattrying to explain freehand drill sharpening without diagrams would be an exercise in confusion so...  http://www.nmri.go.jp/eng/khirata/me...1/index_e.html having said all that, i'd do as Pulser suggests and use a 'unibit' on thin materials- much cleaner hole in sheet metal than a twist drill. as with a twist drill, low rpm, positive pressure and keep it coolShox Dr, nice dissertation- did you write the rest of the article too? http://www.diyfaq.org.uk/powertools/drillfaq.htm
Reply:Originally Posted by hotrodder...having said all that, i'd do as Pulser suggests and use a 'unibit' on thin materials- much cleaner hole in sheet metal than a twist drill. as with a twist drill, low rpm, positive pressure and keep it cool
Reply:Originally Posted by pulserThanks hotrodder, nice to know some one read my post, and actually agrees.
Reply:As a rule I'm not much of a fan of Step bits , but they are good on thin wall.All our drilling is either S/S or ally and Ive found a good quality HSS properly used just as good as Cobalt.A good guess is better than a bad measurement
Reply:I think I might go for either a carbide or cobalt bit. Depending on $$$$. I need a lot more practice on my drill sharpening skilss at the moment.What do most of you use for a cutting compound? I usually just use plain old oil for drilling mild steel which seems to work fine. Is there a good / bad brand Thanx for all your replies. Very much appreciated.
Reply:Originally Posted by juiceI think I might go for either a carbide or cobalt bit. Depending on $$$$. I need a lot more practice on my drill sharpening skilss at the moment.What do most of you use for a cutting compound? I usually just use plain old oil for drilling mild steel which seems to work fine. Is there a good / bad brand Thanx for all your replies. Very much appreciated.
Reply:Yea Brett I live in that vacinity. Good guess mate!!  Where in Syd are ya from?I'll have to go grab some Alu-cut I think.
Reply:Sutherland Shire.........Gods Country  A good guess is better than a bad measurement
Reply:Originally Posted by hotroddercobalt drills are harder/tougher than HSS bits- typically they allow the use of higher speeds.they are useful but not necessary for stainless- HSS will work fine PROVIDED they are sharp, a positive feed is maintained (allow the drill to abrade and the SS will rapidly work harden wrecking the drill and making it harder to finish the hole) and the area is kept cool enough that the chips do not 'colour' high drill rpm and stainless do not go together- recommended drilling speed for ss is 30sfm (around 250 rpm for 1/2" bit) with HSS.135-140 degrees is a common tip angle for stainless but sharpness/drilling technique is more importantmake sure when sharpening that the 'relief angle' is maintained- lose this and the drill will overheattrying to explain freehand drill sharpening without diagrams would be an exercise in confusion so...  http://www.nmri.go.jp/eng/khirata/me...1/index_e.html having said all that, i'd do as Pulser suggests and use a 'unibit' on thin materials- much cleaner hole in sheet metal than a twist drill. as with a twist drill, low rpm, positive pressure and keep it coolShox Dr, nice dissertation- did you write the rest of the article too? http://www.diyfaq.org.uk/powertools/drillfaq.htm
Reply:Sutherland eh!! my mother in law lives in jannalli. Yes, not a bad area.What feild of the metal trade do you work in?
Reply:Originally Posted by juiceSutherland eh!! my mother in law lives in jannalli. Yes, not a bad area.What feild of the metal trade do you work in?
Reply:The factory is at Kirrawee next door to Jannalli Small world eh?A good guess is better than a bad measurementYes. A small world indeed! Excellent workmanship! Ya dont take too bad a photo either.