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Drills Sharpen or Toss?

huskermcdoogle

Stainless
Joined
Nov 11, 2005
Location
South Texas
We are having somewhat of a dilemma here in our tool room. We make cutting tools but are also a distributor for a few companies that sell drills. Do you think it is worthwhile to sharpen a drill say under 1/2" diameter vs just throwing it away and having a small stock of new ones that you reorder when you are getting low. We are mainly cutting T15 and occasionally 4140. These are all being used either in a drill press or in an engine lathe.
 
An SRD grinder can perfectly sharpen a 1/8 to 1/2 inch HS bit in well under a minute. An old one that probably worked OK sold for $150 on eBay a day or two ago. Good used ones usually sell under $500, depending on the model, etc. A new Model 80M is much more. So you have to judge whether your employees can be profitable spending a minute to save you the cost of a new bit. You can also get a quote from an outside tool grinding shop. In the end, volume will be the key to the decision.

Larry
 
I would think that a drill sharpener would be a good investment for your company given the prices of drills nowadays.

I have an old vintage Craftsman drill sharpening unit that I use in conjunction with a 1/3 hp electric motor and a six inch grind stone. It does a perfect job on drills between 1/8" and 1/2". It's also very quick.
 
Well considering we are an outside tool grinding shop and have the equipment to sharpen them about 5 different ways and we are taking another look at this, I am wondering if it is worthwhile to sharpen them with a drill sharpener, due to factors like the point being centered or the edge finish and how long that new point will last vs the out of the package point. I guess I am thinking about this too hard but if you think about how long it actually takes you to go sharpen a drill vs get one from the drawer what is the time difference?
 
I think if you organize the process to put aside the worn drills and then sharpen them in batches, that may be cost effective. Particularly good fill-in work if you have periodic downtime.

If you have to pull out the sharpener each time, possibly not.

If you want to toss a bunch of them, toss them my way :)

Steve
 
You might want to pitch the smaller sizes, since they're cheaper, a bit harder to sharpen, and more likely to suffer with small errors in sharpening. At some point, maybe 5/16" up I'd have to believe you'd save money.

Another thought: what does it say to your customers when they learn "we don't sharpen any of our drills, just throw 'em away. Why would anyone want to pay for sharpening." Pretty soon they might get the idea they, too, should buy the cheapest tools possible and pitch 'em when they're dull??
 
I was going to warn against the mention of "drill doctor" since their products seem to be regarded the same as cheap Chinese machine tools by the mod guy.

But alas too late.

Have you heard of the Brierley? Apparently it's the ducks guts in drill sharpeners. I've been trying to add one to my collection for years but those hungry buggers at the auctions keep sending me home without one.
 
starbolin
Let me get this straight: You're a shop that sells and regrinds drills; You're the one with the expertise; You're the one with five different T&C grinders, and you're asking strangers on the internet for advice???? Something is a bit dishonest in your question.

It seems that you are looking for rationalizations to give to your customers for them throwing their tools away.
That or he sells crap tools that wont last and has no idea how to use those 5 grinders...

Drill manufacturers must like him..
 
For drills below 1/4 inch, buy new. If the
production environment is not challenging then
you could consider re-sharpening those above
that size.

Jim
 
We do know how to use all of our grinders here, though this is the problem. Our tool room does not have much grinding knowledge as they do not do it on a daily basis. Average length of time that one of our tool room guys has been here is 30 years, and they have never been in the cutter grinding department hardly a day in their lives. We have two five axis tool grinders that do high tolerance, step drill and miniature end mills all day long. As far as sharpening standard drills if a customer sends them to us we might do it or farm them out to another shop becuase we have enough volume in the specialty tools to keep busy. But with our customers, screw machine length under 1/2 inch it is usually cheaper to "toss and replace" than have them sharpened due to coatings, and therefore tool life becomes a problem if they are sharpened but not recoated. If there was much downtime we probably would be sharpening our tool rooms drills on a regular basis, which is what one of our part timers does for the endmills back there, but he doesn't have enough time to keep on top of his normal work plus endmills and then drills on top of that. I think I agree that below say 5/16 it isn't really worth sharpening hardly at all, though over that I think that it would be a good idea to have a good drill point grinder kicking around that many people know how to use. Does anyone know of a decent drill point grinder that is easy to use and is very well built, and is also easy to aquire, cost is a factor but if it is well worth owning isn't a problem?

Husker
 
Every drill sharpener I ever used, made the drill cut oversize. For production work, if the hole needs to be on size, I use a factory sharpened drill bit.
Maybe I need a better drill sharpener.
 
We have a Christen sharpener for small, #60 to 3/16" and a Merrylock for 1/8" to 1/2" drills.
and won't hire anyone who can't sharpen the bigger drills to drill to within .003" of nominal size by hand.
We sharpen all our drills ourselves all the time but still manage to have to buy plenty of new ones, just fewer than if we didn't sharpen them.
It takes very little time, certainly less than five minutes each, and is definitely worth doing.

Charles
 
Figure 5 minutes minimum for sharpening a drill no matter how you look at it unless you are free handing it on a grinder at which point you won't get the point you are really looking for. Take this times $50 an hour well you have 4-5 dollars per drill putting a point on it. Anything smaller than .375 or so isn't worth sharpening if you are in the middle of a job. I guess i am looking too hard into a very simple problem.

Husker
 
Do you think it is worthwhile to sharpen a drill say under 1/2" diameter...
That depends primarily on the cost of the operator doing the sharpening. If you find someone for $10/hour, that's one thing. $60/hour changes the equation.

--------------
Barry Milton
 
Husker, I can recommend the TDR/SRD 80M for drills up to 13/16". It takes five minutes to learn and does a factory quality sharpening job in less than a minute. If there is a big chip or badly burned edge, it takes longer, of course. It is more efficient to do the bits in groups of all nearly one size, but it still is a quick job to set the table travel stop for different diameter drills. I have several of these grinders and have sold a few others on eBay. I have had thirty-year old machines that were about as good as new. I know they are one of the best grinders, and probably the easiest to use.

You can get a new machine direct from the factory for a bit less than the price for which MSC sells them. The factory is near you, at Port Byron, NY. They used to offer a free trial, but I don't know if they still do.

TDR/SRD drill grinders

Larry
 
If you do decide not to sharpen them please put them up for sale here. I would buy a bunch of them just to learn how to sharpen them. I assume they're decent quality drills.
 
Will second the recc of the SRD drill sharpener, but there are certainly others out there.

Seems to me this is a simple cost benefit analysis problem.

1. Do you have a machine to sharpen the drills, and if not, how much is your acquisition cost?

2. Do you have a person to do this and what is the true cost per hour of that persons time?

3. How many drills can that person do per hour and what volume of resharp candidates to you have per month?

4. Will the resharpened drills meet your needs as to quality/tolerance of holes and longevity of tool (vs new)?

5. What is the true cost of new drill bits, including acquisition time and expense delivered and in stock?

And the answer is?
 
I've got an old Darex M3 for my home shop (since replaced by other models) with chucks up to 1 1/8". What I can say in its favor is that it is absolutely quick and simple to use. I can go from a dull drill to a sharp one in three or four minutes, including the time to walk to the grinder and back. Something equally simple might be what you want in your tool room.

My own cut off for "to sharpen or not to sharpen" is around 3/16" unless it's the last bit I have of a size. Fastest way for me is to save up a bunch of dull bits and sharpen similar sizes together, so there's less adustment of the chuck. Most anyone can easily sharpen $100 worth of mixed bits that way in an hour.

One of the biggest advantages of sharpening, IMO, is that I'm much more inclined to use a sharp bit than try to wring more life out of a dull one. If your own folks felt the same way, that might add a bit to productivity, hole quality, and safety for odd jobs. For production lines, I agree, the pros and cons are different.
 
I'll get back to you all as to how this all works out. I need to go through and see how much time we are spending sharpening vs how many we would be buying or if we could get a re sharp bin going for each size drill in the drill drawer. This is basically my next days project as I am doing a time analysis on all of our blanks so we can find our problem areas. Currently my gut feeling and my bosses gut feeling is that we are not making much if any money other than customer satisfaction / retainment by making these blanks and finished tools. So there is much to be gained here and this is definitely not the only place that we can gain significant ground on.

Husker
 








 
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