A Handy Skill To Know

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Good tips there, Tom I have 65+ lbs of drill bits 9/6" dia and under that needs sharpening if ya have any spare time. I keep most bits I have sharpened and if I put all the sharp bits together with the dull bits there would be several hundred lbs of them from 1.5 on down to the finest 1/16" ones. For the smaller bits 1/4" and under a Drill Doctor will do a passable job of sharpening.
 
Good tips there, Tom I have 65+ lbs of drill bits 9/6" dia and under that needs sharpening if ya have any spare time. I keep most bits I have sharpened and if I put all the sharp bits together with the dull bits there would be several hundred lbs of them from 1.5 on down to the finest 1/16" ones. For the smaller bits 1/4" and under a Drill Doctor will do a passable job of sharpening.
Thanks Jerry :) haha I’ll politely decline sharpening them! Never tried a drill doctor, but glad it’s acceptable. Sometimes simple tools just allow you to get the job done, even if it’s not to the standards of other methods. A bit like the 2 in 1 sharpener, results are passable, but if they let you cut wood, it’s all that homeowner may need, not to mention sometimes doing things freehand causes more problems than it solves right?
 
Thanks Jerry :) haha I’ll politely decline sharpening them! Never tried a drill doctor, but glad it’s acceptable. Sometimes simple tools just allow you to get the job done, even if it’s not to the standards of other methods. A bit like the 2 in 1 sharpener, results are passable, but if they let you cut wood, it’s all that homeowner may need, not to mention sometimes doing things freehand causes more problems than it solves right?
Tom, if you think that fellows have a difficult time free hand sharpening a saw chain ,then give them a drill bit to free hand sharpen, no jig just hold it in their hand and sharpen it, my bet there is less than one in a hundred that can make one cut and stay centered. I have seen this first hand working with just about all the different trade guys there is, only some of the machinists I have worked with could sharpen a drill bit somewhat close to sharp or that it would cut/last more than a few revs. The first day I was in the shop at vocational school the instructor handed me a 1" lathe bit and just said sharpen it,I want to see how you can use your hands. I did and when completed he had the class stop what they were doing and huddle around, he passed the bit around to each student, we had two female students in this class so I cannot say just guys. After each individual had a close look he announced, this is what I want to see each and every one of you to accomplish this year, he then turned to me and said, I could do no better myself. Bob and his father Owen were life time machinists I knew them both well. When it came time for us to grind our new blanks into threading bits I ground mine with a 15 degree right hand offset and it passed the test first time round while many others were on their 8-10 th attempt to grind their bits so they could fit the test gauge. All I am saying is that some people can use their hands while others need a jig or machine to get the job done We are all different and have different aptitudes, I would make a lousy computer programmer.LOL
 
Interesting thread. Because I own and operate a short run machine and fabrication shop and I have my Journeyman's card in tool and die making from the defunct Standard Products in Cleveland, Ohio, I acquired the skill of 'offhand sharpening' twist drill's a long, long time ago. Actually, my late father taught me way before I set foot in a machine shop.

I use a General Tool drill point gage to check the point angles and to make sure the cutting edges are equal on both sides of the web. I don't check every drill, just the smaller ones, under 1/8" and the really small ones, because of my age and eyesight, I just toss and replace with new ones and I don't buy cheap import bits either. I only purchase Cleveland Twist, Chicago Latrobe or Triumph and I hardly ever buy or use coated bits, ie: Tin coated which is nothing more than a thin coating of Titanium Nitride which supposedly aids in chip flow up the flutes. Cutting lubricant does the same thing and we use cutting lubricant when drilling, always, One of the favorites in this shop is 'Tap Free' lubricant or flood coolant where necessary.

Never owned a homeowner grade Drill Doctor, however, I do own a tool room grade Darex drill and end mill grinder and it's not something the average homeowner can afford anyway. I bought the one I have at a machine shop auction sale and it was still almost a grand to buy. A new Darex end mill and drill grinder will set you back around 2-3 grand, if you are that flush. I use mine mostly for sharpening multiple flute end mills, not twist drills, though I can sharpen them on the surface grinder using an offset fixture that gives the proper relief angle when chucked on the magnetic chuck.

The China based Vevor offers an really nice twist drill sharpener that employ's ER collets (extended range collets) to accurately sharpen drills and I've read it does a much better job than the homeowner grade Darex does, but it ain't cheap either. You will pay a couple hundred for it.

Offhand drill bit sharpening as well as relieving the webs is an acquired skill that takes practice and lots of it and expect to not be good at offhand sharpening without a lot of practice and scrapping a ton of drill bits. The true test of accurate offhand sharpening is when each cutting edge produces a uniform chip when drilling into metal. Equal cutting edges are also important because unequal cutting edges will produce an oval hole, especially in smaller diameter holes. I offhand sharpen just about everything up to and including the Silver & Demming, large diameter drills which can be as large as 1.5" in diameter and I can either use a bench grinder (have a couple Milwaukee pedestal mounted bench grinders or I can use the 12" diameter flat platen deburring grinder with a PSA disc installed. However, using a flat platen disc grinder entails a somewhat different technique for holding and grinding a bit.

Parabolic twist drills as well as left hand (die reclaim drill bits require a different sharpening technique. Kind of like TIG welding, don't expect stellar results without a lot of practice and a lot of scrapped parts. Took me quite a while (and I had a good teacher who is nuclear certified in exotic alloys) to master TIG welding in exotic alloys.

It can be frustrating when starting out (drills and TIG welding). Takes a lot of skill to master offhand sharpening, just like TIG welding and stacking dimes takes skill and practice, practice, practice.

Finally, remember that the drill point (relieved or not) must be parallel and in line with the cutting edges or the drill will wander when starting to drill a hole, any hole and if the drill point isn't parallel, that is a sure fire indicator that the cutting edges aren't equal either.

Get yourself a drill angle gage (they are not expensive) and use that to determine if the cutting edges are parallel and equal. I have an old General Tool gage I check mine with. I believe they are less than 15 bucks, even today and I bet they are on Amazon as well. Of course left hand drills and parabolic drills cannot be checked with one, only conventional 2 flute right hand cutting drills can be checked but, most drills for general use today will be right hand cutting drills any way.

Finally, watch your cutting speeds and use a liquid lubricant when drilling metal. The lubricant extends the life of the drills, carries away heat from the drill tip so they last longer and avoid cheap carbon drills. Always buy high speed steel drills and avoid the import crap if you can and if your wallet can afford them.
 
For years I have sharpened them by hand. Sometimes I would get them "fairly" close...
Then, fortune came my way.
Lisle 91000, it isn't a simple task to get setup. However, it works.
Is a LOT more precise than the plastic drill dr things are.
likewise, I have 20 pounds of drill bits to go thru....
1731690648725.jpeg
 
Careful Careful this topic can be as controversial as an oil tread :surprised3:
Nothing will teach you better than doing a toolmaking apprenticeship, learning from old school masters.
I drilled the waterways on a 4 mould bases 3 by 4 foot, lots of through and angled holes in tough P20 tool steel, probably 50 meters of drilling. As a 3rd year apprentice, drilled and sharpened all day every day for 3 months solid. Hated it at the time:rare2:
My tip is use a bench grinder with a thinned down tool post. Mark a 53 degree angle on the post at your guide for the tip angle and roll the drill to copy the original angle which is 5 degrees. Second once done measure from the outer cutting edge to the inner Web cutting edge. Get them even. If you don't the drill will cut over size
The way you have done it in your video will cause a lot of chatter in tough steels like stainless. The additional 15 degrees of relief will cause the drill to be weaker and not as solid. That's why they come from the factory with only the primary 5 deg, its rolled to make it as solid as possible, no secondary relief angle and no straight edges.

If you really want to learn how to sharpen a drill, drill through 50 meters of tool steel LOL.
I will give you credit for doing the video, it's simple and will work for most people. Better than throwing out drill bits when they get blunt.
 

Latest posts

Back
Top