drill bit sharpener

   / drill bit sharpener #1  

htiek126

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Are drill bit sharpeners worth the money? I drill a lot of holes in steel, and I wear out a lot of drill bits. If I resharpen the drill bits, will they still perform well for drilling steel? Or will the hardness of the drill bit be ruined (or perhaps is already ruined) and then not stay sharp?

Keith
 
   / drill bit sharpener #2  
My understanding is that the hardening agent they place on the metal is removed when you use the sharpener. For this reason I tend to keep using them until they no longer will cut well and just replace.
PJ
 
   / drill bit sharpener #3  
We resharpen almost all of are drills at work. They work just as good as new ones. the drill sharpeners do a better job than trying to do them by hand on a gringing wheel. The question you need to ask yourself is how much do I spend on drills compared to the cost of the sharpener, and will I make this money back. If not then just replace the drills as you need them. These work well for sharpening drills. http://darex.com
 
   / drill bit sharpener #4  
If you drill a lot of holes a drill sharpener will pay for itself very quickly. You save not only the cost of the bit, but also the time saved by using a sharp bit instead of making do with a worn one.

Btw, one of the quickest ways to wear a drill bit is by using it at too high a speed or with not enough feed pressure. A drill bit stays sharper if it's cutting, as opposed to rubbing over the surface. Look at your chips as they come out from the flutes. If they're thick and long the the drill is cutting properly. If they're like powder, then the drill is too dull, or your drilling at too high a speed. Once the chips turn to powder, the bit is useless for further cutting.

Drill bits are not surface hardened, so you will not lower the hardness by resharpening it, as long as you do not overheat the bit during the resharpening process.

Drill bit sharpeners come in all price ranges. I have one that cost $6500.00 when new. I found it at an auction and paid $75.00 for it. It was missing the tailstock, but that was easily remedied with a chunk of alum. and a few hours on the milling machine. This sharpener puts a grind on a drill bit that is better then the factory grind. In fact, I often use it to regrind a new drill bit before use.

The problem with the real cheap drill sharpeners (the $29.00 units) is they don't put the proper relief angle on the bit. The drill doctor units are about the cheapest you can buy that will make a decent regrind. But I have also heard some complaints about the lower line drill doctor, the one that sells for around $130.00. I've never used one myself, but I've heard of guys returning it because the chuck flexes a lot, which makes it hard to get an accurate grind. If the two cutting flutes are not ground exactly the same, the drill will walk off to the side when cutting.

Drill doctor makes a number of different models, and IIRC, the decent ones go for about $500.00 and up. You can often find drill sharpeners on ebay, but even there you usually have to pay a pretty good penny for a decent one.

FWIW,
Dave
 
   / drill bit sharpener #5  
I have the $150 Drill Doctor (two chuck's) and after learning how to operate it, (that took some time and patience), I am very happy with it, and enjoy having sharp drills to use all the time. Below 1/8" diam is the limit for me. But the cost (as already stated) must outweigh the cost of just buying new bits. I believe I can sharpen them better (at least it seems that way) than how they come new. I think that is because one can grind the back relief, which I like.
 
   / drill bit sharpener #6  
I must be way off base here comparitively speaking, but I've freehand-sharpened my drill bits for YEARS using the side of the grinder wheel. Yes, I know that they make special tools for that, but I can just quickly walk over to the grinder and swoop-swoop-swoop-swoop put a good cutting edge on any bit that I can still see, way down to the lower end of the drill index. Sometimes I'll buy a bit, try it and if it doesn't cut well enough I'll touch it up freehand and away it goes. My Ag Shop teacher taught us how to freehand sharpen, and it has stuck with me for more than forty years. Send me your cast-off bits and I'll enjoy using them after a quick trip to the grinding wheel.
 
   / drill bit sharpener #7  
Hey CJDave
How about a little tutorial for those of use who did not have the opportunity to learn this technique. If not a tutorial, are there some tricks and tips you could share with the rest of us. Maybe you won't want to if folks start sending you their dull bits /w3tcompact/icons/laugh.gif.

Bob
 
   / drill bit sharpener #8  
I learned from the same place and still
do many bits that way.
U can also split the point to let the
drill start and drill easier.
It's hard to explain how to sharpen drills,
easier to show how it's done.
It takes some practice to get the drop and roll.
 
   / drill bit sharpener
  • Thread Starter
#9  
Thank you for the information. I plan to look for a sharpener for the larger bits up to about 1". They are the costly ones. I am planning to buy a drill press, which should also increase the life of the bits. This past year, I have been using shaft collars for many applications. I cut holes with my torch, and then weld in a shaft collar. I found it to be much faster and cheaper then ruining $20 drill bits.
 
   / drill bit sharpener #10  
Keith
Like others have said. It’s hard to explain how to sharpen drills. I have scanned a page from my 1932 American Machinists Handbook. Hope it will help you understand how to sharpen drills.
The first job I had when I got out of high school was at a shop that made auto parts. We had to learn how to sharpen drills by hand. The Toolmaker at the shop did not like sharpening drills. His goal was to teach everyone how to sharpen drills so he would not have to do it. He did a good enough job that, 45 years later. I would not consider spending money on a drill-sharpening machine. /w3tcompact/icons/smile.gif
There is a drill point gauge that is used to check the angle and width of each cutting edge of a drill. Found one at Tool-Plus for $10.59. I’m sure you should be able to find one at a local tool store.
 
 
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