Pox upon Home Depot drill bits

[Dale R. Hamilton]

I've had it with cheapo drill bits- titanium, molylibdynum, unobtanium-coated- make no difference. None will hold up drilling steel. I have a whole collection of drill bit sharpening
devices- bought with the childish belief that a drill bit would last long enough to require re-sharpening. How about your experience- anybody found some HSS bits that provide good service?

[Memphis Mike]

The best drill bits I've ever seen for
drilling steel are the titanium ones
bought at Walmart.

They're the only thing I've ever seen
that will go through a Medeco vending
machine lock without breaking.

As far as sharpening. Nothing beats a plain
old bench grinder. But you have to know
the technic. ;)

BTW, just so you'll know I'm not breaking
into vending machines, I'm a vending machine
repair tech.

[ 12-26-2002, 05:29 PM: Message edited by: Memphis Mike ]

[Dave Fleming]

Teenut, was an ***ace machinist*** who posted to the Rec.crafts.metalworking news group before his early death from cancer ayup that smoking will get ya.

This is a copy of instructions for hand sharpening drill bits as
originally posted in rec.crafts.metalworking by Robert Bastow (teenut).

------ Teenut's instructions -----

Anyone who wants to learn this skill should start large - and I mean
1/2 inch and above. This is a great way to make long drills short.

I believe I learned on a 3/4" taper shank drill..it is a lot easier to
see all the angles and begin to understand how they work and interact.

By the way..we had a handy little dohickey to help get the drill lips
level. I have never heard it described before..

For the morse taper shank drills from 1/4" up to about 1" diameter, we
had a piece of 2" by 1/8" hot rolled steel strap..about 14" long. One
end was bent at right angles, about 2" from the end to form an L shape
with one 12" upright and a 2" horizontal. In the geometric center of
this short leg was afixed a "dead" center..not a lathe tailstock
center!!...more like a 1/2" bolt, 1/2" long, turned or ground to a 60
deg point (Approx...no great precision required) and screwed in from
the under side. Thats IT..toolmaking over!

In use the inner face of the upright was coated with whitewash (Never
SAW marking blue 'til I got in the toolroom!) The drill was ground,
freehand, on the FACE of the wheel (not the flat side)...care being
taken to keep the POINT angle as equal as possible on both sides..I'll
tell you how to do THAT in a moment..

Lets do that now in fact..

Jim, You are dead right about not being able to grind a drill without
mechanical help! Well here's how you create your own "6 Million
Dollar Bionic Darex" ;^)

Let's assume we are going to sharpen a 3/8" diameter, 2MT shank
drill..it is about 8" long (these figures are arbitrary..I just want
every one to have the same mental picture of what I am describing. We
approach the wheel, which has been dressed on its face, dead straight
across with no grooves..(Ve SHOOT anyone ve catch putting grooves in
ze drill wheel!!..No Pity..No Prisoners..Ya! Verdampt!)

(Sorry)...

The drill shank is held firmly in the RIGHT hand...ALL the movement
and control is imparted by the RIGHT hand. For the purposes of drill
grinding, the left hand could be...with benefit..a LUMP OF CLAY!!

It is from this "lump of clay" that we fashion the Bionic Darex".

Place your left hand thumb and forefinger tips LIGHTLY together..Relax
the other three fingers and let them naturally curl against the palm
of your hand. Let the drill flute drop into the vee between thumb and
forefinger and let the tip of the finger "Find" the curve of the flute
where it fits comfortably. The tip of the thumb rests on the sharp
junction ot the land and the flute, about an inch back from the drill
tip.

Now...SQUEEZE HARD!!! YOUCH!...I said it would be easier if it were
clay! 8^) Lift the drill from your fingers...see the GROOVE?...Drop
the drill back in..it locates within a thou or two! Magic?..Bionic at
least! Squeeze again to set the groove. You have created a
customised drill guide that fits better that that on any machine ever
built! You can relax your grip now..feel how smoothly the drill will
ride back and forth, guided by the groove you have created for it.

Place the knuckles of your left hand, LIGHTLY on the ginding wheel
tool rest, and swing the drill shank, from left to right (using ONLY
your right hand) and push the drill lengthways though that groove in
your fingers back or forth using the groove to make the drill twist or
"rifle" in your fingers. Do NOT move your left hand in any way..it is
made of clay remember!

UNTIL....

A) The drill axis is "eyeballed" to be at half the required point
angle to the wheel face...You can scribe or chalk reference lines on
your grinder benchtop to help you line this up..at least untill it
become almost second nature.

B) The drill axis is dropped JUUUst below horizontal. This will
ensure that your soon to be ground drill lip will start with a
"smidgin" of cutting clearance.

(Ideally, and certainly for a beginner, the grinder rest should be set
dead radially to the wheel center and about half the drill diameter
below the true center of the wheel)

C) The two cutting edges of the drill..the straight, sharp bits,
formed by the junction of the flute and the back face (the only bit
you grind), should be horizontally disposed..with the edge uppermost
on the side closest to your left hand..the other sharp bit of course,
pointing downwards (Jeeze this would be a lot easier with a sketch
pad)

This I will call the SET or START position!

NOW, move your left hand for the first, last, and ONLY time during
this whole exercise. GENTLY ease the cutting edge towards the
spinning wheel, carefully maintaining all the angles and orientations
of the SET position..until the cutting edge is JUST shy of touching
the wheel. If you listen carefully you will hear the tone of the
entrained air, whistling through the narrowing gap. You will hear a
subtle but distinct change of tone JUST, I mean Just...a couple tenths
of a thou BEFORE the edge touches the wheel. STOP!!! FREEZE!! DO
NOT MOVE!!

Now, press the knuckles of your lump of clay..sorry, your left hand
FIRMLY down onto, into and around the grinding rest..establish a
"Groove" on the back of your hand as well as between your fingers.

We are now ready to grind, Your left hand locked to the drill and
grinding rest is otherwise quite relaxed..letting the drill slide,
twist and tilt wherever your right hand and the groove in your fingers
tell it to go.

The actual grinding is a bit of an anticlimax.

You have previously studied a new drill point, you have read about
clearance, and cutting angles, and rakes and......

With the RIGHT hand in control, gently, kinda, lean forward... bending
or squeezing your arms hands and body..rather than actually moving
them..untill you take up that last couple of tenths and the wheel
begins to cut. Let it cut..don't force it, and don't rush it..it
really won't hurt anything if you take a full minute per pass per
face. YOU and your "Bionic Darex" are totally in control of that
drill and the wheel..Forget the times when, close to panic, you swung
the drill wildly past the wheel, hoping to get "the dirty deed" over
with as quickly as possible.

Take your time, enjoy the moment, THINK about the shape you are trying
to generate. Just the one face is left to "Interpretation"...every
other aspect,angle, facet, what have you...Has ALREADY BEEN TAKEN CARE
OF!! and is locked in place under your control!

The right hand should perfome a "Lower Quadrant sweep" for want of a
better term. An observer behind you would see your hand move from
about 17 minutes past the hour on a clock face, to roughly 25 minutes
past. But it isn't a smooth arc of a circle, more a sector of an
elipse..You see, as your hand starts to drop slowly, you are also
rotating the drill in "the groove"..the first third of the turn needs
to maintain that very slight clearance angle on the cutting edge, and
not increase it too rapidly.

You need the clearance to cut..But too much at that point will WEAKEN
the edge, and cause the drill to snatch and chip...So the first part
of the rotation is ALMOST but not quite, just as though you were
grinding a straight cone point on the end of your drill. Only as you
approach the second third, does your right hand start to noticably
drop..kinda "Catching Up" on the rotary motion...increasing the
clearance as it does.

In the last third of the rotaion the right hand drops quite
rapidly..Thogh not enough to catch the OTHER drill lip on the
wheel..that lip is coming around quite rapidly by now.

Above all, take your time, if it helps, move the drill one degree at a
time, and think ahead what shape or angle the next degree of cutting
face needs...Remember, you have control, and IT ain't going nowhere
'til you decide.

After a pass on one face, flip the drill in your "Bionic Darex" DO NOT
MOVE THAT LEFT HAND!!, return to SET position and repeat, the pass on
the other face.

Having done a couple of passes on each face..it is now time to check
the results on our homemade "Optical Comparator"

(Sorry Jim I couldn't resist!!) ;^)

Rest the center hole in back end of the drill shank, on the center
point of the "Comparator" and use, first one and then the other drill
lip to scribe a light line on your whitewashed (OK Blue or red dyed)
surface.

You will readily see if the lines coincide..if the lips are even..or
not, as the case may be.

Lets assume they are..Now look directly DOWN on the end of the drill
to check the clearances. HUH? How can you check radial clearance by
looking it staight in the face? Surely you need to look at it
sideways?

Well no you don't...for once all those interacting and confusing
angles and faces and clearances are going to work together in YOUR
favor and make what could be a tricky bit of metrology..quite simple.
While we are looking at the end of the drill, we will also check that
the POINT ANGLE is correct too!!!

(Ok guys, leave quietly..teenut has finally lost it!!)

No really, trust me. IF you look straight down on the point of a well
sharpened, standard drill, you will see the two cutting edges, joined
by the CHISEL edge which crosses over the web of the drill. The angle
fromed by the chisel edge to each cutting edge should be ABOUT 50
deg...anywhere between 40 and sixty is ok for a first attempt. (I can
hear the purists and theorists screaming and lighting up their flame
throwers.) But believe me, get it in that ball park and your drill
will CUT. If the angle is too steep..you don't have enough
clearance...negative clearance will give you an angle event greater
than 90 deg. Too MUCH clerance and the angle will appear too shallow!

While looking at the end, check the point angle, How? Look down the
axis of the drill at the cutting edges. Are they straight? If so,
your point is pretty close to the right angle (As designed for that
drill, by its manufacturer when he set the helix angle and the cross
section of the flute) If the edges appear CONCAVE the point is too
flat and if they appear CONVEX, the point is too "Pointy"

If your drill passes all these tests, which take but a second or two
to perform, THEN IT WILL CUT..pretty close to size, without
chattering, chipping, overheating, wandering or seizing. I guarantee
it!

Hey, thats a pretty good start for the first drill you ever ground!
All it takes now is a bit of practice for it to become second nature
and almost as easy with a little 'un or a big 'un!

Hey guys!

My apologies for "goin'on" but If it helps just one person to pluck up
the couragre and go hand sharpen his (or her) first drill, by hand...

Then I hope you will bear with me.

It is late, I am tired and I am not even going to proof or spell check
this,

'night all

teenut

[Memphis Mike]

Thanks Dave. I was taught how to do this
{only not exactly as Teenut} 15 years
ago by an old timer.

I think it's something better demonstrated
than described in writing.

[Dave Fleming]

Agreed Mike, that is true. I tried and tried to get the 'hang' of it but never seemed to get it right on the button,sigh.
Finally I bought a DAREX M-5 with all the bells and whistles. It works just fine BUT I still have that coffee can of dull bits sitting on a wad of cotton soaked in autotranny fluid to keep from rusting as well as all those files and rasps that I really should send to Boggs up in the LA area for sharpening/refurbishing.
Oh well someday... :rolleyes:

[Memphis Mike]

Yup, I'm no master by any means either but
I found the tip about using a downward
type pressure on the bit the most useful.

It tends to sharpen the edge and the point
instead of the back section which really
isn't used. If ya folla.

[thechemist]

Originally posted by Dave Fleming:
<snip>I still have that coffee can of dull bits sitting on a wad of cotton soaked in autotranny fluid to keep from rusting as well as all those files and rasps that I really should send to Boggs up in the LA area for sharpening/refurbishing.
Oh well someday... :rolleyes: Who is this Boggs in the L. A. area that sharpens files and rasps? I didn't know that could even be done.

[Jerry Sousa]

Oh my God! Can it really be that "the Chemist" has claimed ignorance on a technical matter? Now that is remarkable!

[Dave Fleming]

Only shows ta go ya... :D
That everybody can't know everything. :rolleyes:

File Sharpening (http://www.boggstool.com/)

[Wayne Jeffers]

Dale,

You are using cutting oil when doing serious drilling through steel, aren't you? ;)

Wayne

[Lowell Bernhardt]

All this talk about "IUM" coatd this and "IUM" coated that. About the best drill bit I have found for drilling steel plates up to 1/2" thick is 308cal armor peircing. Clean thru every time. Just a few saftey reminders, watch that your feet aint under the work surface while drilling. Oh yeah saftey glasses and all that jaz. :D

Then there's the newest bits from the labs at NASA. Uranium coated bits! Not only do they allow you to work in the dark (cause they glow) but they're guaranteed to hold an edge for at least 10,000 years. The only problem that NASA has come across is this. DRILL SLOW!! High speed drilling operations can cause those pesky mushroom clouds. :D

[Memphis Mike]

Seems to me that "some" folks don't know
anything about file cards. :D

[ 12-26-2002, 10:08 PM: Message edited by: Memphis Mike ]

[Dave Fleming]

SOME folks know very well how to use a file card and that little steel toothpick that fits in the leather pad on the handle. But all good files and rasps do have a finite life. That is where the BOGGS connection comes in. If for a relatively small amount of money they can revive a 14 inch Mill Smooth file that hits the scales at over $15 USD, one would be a fool not to take advantage of the process.
And if one has a rather large file selection and if some of those files get worn which WILL happen then ya see where I am goin' with this?? ;) ;)

[Mr. Know It All]

Learning how to sharpen a drill bit on a grinder took me years. Lots of trial and error. I should pay better attention to what type/brand of drill bits we use at work. I know they're cheap and have to admit they work pretty good. Watch out for them hot chips! :eek:
Peace----> Kevin in Ohio

[capt jake]

Smooth file that hits the scales at over $15 USD, one would be a fool not to take advantage of the process A relative price to revive such might be in order?? 'Ball Park'??

[Dave Fleming]

Captn J., hit the site and see for your self. ;)

[ 12-27-2002, 12:45 AM: Message edited by: Dave Fleming ]

[Dale R. Hamilton]

Wayne- I'm not using cutting oil on steel- only plain old 30 wt. Is there a difference?

Appreciate all the instruction on drill bit sharpening. It would be a fine thing to know- but I just don't have the patience or the time to sharpen a miserable drill bit. Thats why I don't do fine jointery, dove tails and all that marvelous stuff.

Good tip Memphis! I don't think I've tried Walmarts bits- but I will now thanks to your suggestion. A vending machine lock ought to be as tough as a Mack truck frame. Any chance you might be headed west on the interstate this spring?

Dale

[Wayne Jeffers]

Dale,

I can't speak to the difference in the oils. I've only used cutting oil. Keeping the bit lubed (cooled) with cutting oil seems to keep it cutting instead of generating so much heat. Also keeps the bit from dulling so fast. I can't recall drilling anything tougher than mild steel and I use HSS bits, but I've gotten good results with that combo when using cutting oil.

Wayne

[Leon m]

I just drilled over three hundred holes
in 3/32" stainless steel last week .I used
H.S.tungsten(spelling ? )and cutting oil.
about mid-week I took some bits to my
father in laws (master sharpener of all things)
now that he's getting older he uses a
Drill Doctor ,it did a good job!He said
not to get the cheap $60 one ,but the next one
up.to Quote him "BUY ONCE SAVE TWICE"

GOOD LUCK.....LEON

[imported_Krueg]

I've had good experiences drilling steel with cobalt drill bits. They're not terribly expensive, so if you haven't already, maybe you could try them. They are very hard.

Eric

[Rich VanValkenburg]

This was a keeper thread. My dad can sharpen drills like nothing I've ever seen. He's tried to teach me many times, but the skill still eludes me. Whenever I need a drill sharpened, I'll call him up and say, "Dad, can you try to show me how to sharpen drills again?" He just laughs and then he's there in five minutes. I've got to seriously pay attention this time, since last week his doctor talked to him about pancreatic cancer.

And yes, EKrueger, dad gave me a set of cobalt drills. Very hard. Low speed and oil on the drill press.

Rich

[ 12-27-2002, 11:56 AM: Message edited by: Rich VanValkenburg ]

[Mhija]

This may be obvious to everyone else here but it
took me a little time to work out...being prone to
doing things the hardest way possible given half a chance. The drill speed seems really critical to
the efficiency of the task. Particularly in soft
metals like aluminum. When it's dialed in you get
those nice curls of metal instead of dust & chips.

[Ross Faneuf]

I actually worked as a machinist once (very briefly, and long ago); and I remain a bit surprised that more people don't know how much better machining operations go if you

1. Use the right tool speed
2. Use tools sharpened to match the material
3. Use an appropriate lubricant/coolant

'Tool speed' refers to the speed at which the cutting edge of the tool moves into the material. Reasonable cutting speeds for mild steel may be about 100-200 fps (WARNING: ancient numbers, use for comparison purposes); for free-machining aluminum alloys like 6061-T6 they may run as high as 5000 fps. Thus you speed up your drill press for small bits, slow it down for large ones. You could leave your drill speed at max speed for all aluminum work if (a) it has enough power (b) you clamp all work very carefully.

Mild steel really likes cutting oil; cast iron does well with Crisco. Aluminum is fine with lots of lubricants, including whatever oil you can find, kerosene (if flammability excites you) or soapy water. In a machine shop setup, with LOTS of lubricant/coolant, you can take off as much as 10 times as much material in a pass and still get a better machined surface.

Etc. Take a look at 'Machinery's Handbook' at the library (expensive book) or the Pocket Reference version (very useful and MUCH cheaper).

[George Roberts]

Having been a machinist at one time I can agree with Ross.

right speed
right cutting angles
right lubricant

I will only add

If the bit wobbles, then the side of the drill wears at the tip and all of this wear should be removed when you sharpen.

Sharpen before you think the bit is dull and there is less work.

Wood cuts at 3000 sfpm (surface feet per minute). Mild steel at 100 sfpm. You really want slow speed in your drilling.

[ 12-28-2002, 05:56 PM: Message edited by: George Roberts ]

[Dale R. Hamilton]

I never knew any of this stuff about drill bits. I usually just grabbed the right size, or near it, and soused down on it till it smoked. Oil? what oil? Thanks for the information-maybe my bits will last longer.

[Ross Faneuf]

Thanks, George; a measure of how long it's been is that I used fps instead of sfpm (which is correct).

[shadow99]

Ross has got it right, you need the correct bit, running at the right RPM, and the ability too feed it at the proper feedrate. Lubrication on some materials is required i.e. (stainless steels, plate steel).
The best drill bits are M2 colbalt, Titanium coated or uncoated, as a machinist I've put these bits thru more torture than any other bit available. They are much tougher than HSS, but not as fragile as a carbide bit, they can be resharpened until there is hardly any flute left.
When resharpening on a bench grinder, keep tool cool with water, use an inexpensive drill angle gage ($ 5.00) to keep cutting edge angles proper. Most popular are 118 & 135 degree, point spliting provides a means of self centering (eliminating center-drill). After sharpening several thousand drills over the past 15 yrs its like shapening a pencil.

Rick

[Barry]

http://www.bitsnbores.com/

Try Here: Fuller majkes good Drilling materials

Bit Speed Reference: http://www.bitsnbores.com/html/speeds_feeds.html

[ 12-31-2002, 03:29 PM: Message edited by: Barry ]

[Dave Fleming]

Thank goodness there is WL Fuller to supply good stuff especially after Greenlee stopped making wood boring bits sold the division to Forrest City and now can't seem to find Forrest City!

[bromleigh]

May I suggest that if you are running the drill at the correct speed "AND" the included angle of the bit is correct "AND" you have sounter sunk and/or drilled a pilot hole for guidance, that no HSS bit that I am aware of should require any lubricant whatsoever.Incidentally try mounting a tool rest with a angled groove especially for drill bits, it helps, also , buy jobber bits from a machine shop supply house.

[Mrleft8]

..... Reminds me of the time I literally melted a drill bit trying to drill some 1/4" stainless steel. How was I to know that you can't drill stainless with a carbon steel bit, just by making :D it spin as fast as possible?

[ion barnes]

Bromleigh scores! Your right on the money. I was on the thread about drill sharpeners a couple of days ago and the same things came up too.

If you go to home Depot you will get drills designed to drill soft material as in wood particularily and will do a reasonable job in aluminum. For any kind of steel, you need a drill designed for steel and a jobbing shop is one place to go. Also try an auto-parts supply house. Or a machine shop but they will probably not sell to yopu but point you in the right direction.

The angle of drill point is important as well as being in the center. We sumtimes when we did not have the correct drill would grab one size smaller and recut the point off center to open up the drill size. crude but ......The softer the material the sharper the angle... in most cases.

A rule of thumb for steel is, you should be able to see the individual flutes as the drill bit spins. Go slower than faster and ALWAYS us a drill bit thats stamped on the shank right next to the drill size notation, (HSS) that means High Speed Steel. Thats the quality of drill you have to use.

Each drill with use becomes dull and will not cut. You will know this by the change in caracter of the drill shavings. You should see long curls, equal length for each flute, and not little granules. To extend the life of a drill bit, and make things easier with tough metals like stainless steel, you should use a cutting oil or fluid. You can get cutting oil where you buy your drills. I use either but not both together.

I could go on but wont except to say that all these titanium or cobalt coated drills are crap in my eyes, it a marketing ploy to be avoided. Look for Dormer or Starret brands. If it can not stand to have a brand name you can recognize, move on. Any questions?