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I'm looking to buy some quality drill bits and was wondering what you guys suggest as far as material is concerned. They will be mostly multi-purpose bits, but I figure if I buy high quality bits intended for drilling metal then they will work on just about everything else.

HarborFreight.com has a 115 piece set of Titanium Nitride Coated bits for $39.99. They also offer a 115 piece set of Cobalt bits for $99.00. I assume Cobalt is the way to go in terms of strength, but are they worth 2.5 times as much as the Titanium Nitride bits? Or are both of these sets crap, and I should find another set somewhere else? Thanks.

Some Sears Craftman Titanium drill bits are good quality for a medium price. Back when I turned wrenches for a living, I bought my sets of Titanium drill bits from my Matco tool dealer. I was able to beat the hell out of them...day in, and day out, with out a problem. Be prepaired to spend about $100 for a 40 piece set of those.

I have a set of RYOBI Titanium bits I bought on sale for a decent price from Home Depot. They are OK for ocassional home use, but would probably not hold up for daily professional use. Stay away from Harbor frieght anything, which requires even a small amount of quality. I bought a set of drill bits from them that snapped like twigs.

Stay away from Harbor frieght anything, which requires even a small amount of quality. I bought a set of drill bits from them that snapped like twigs.

I kinda figured that might be the case. I don't mind spending $100, but I want quality if I am going to shell out that much $ for some bits. Most of the Craftsmen stuff I see on the Sears website is about $100 for sets of 29 bits. Is Cobalt any better or worse than Titanium? They have both, and they are about the same price. Thanks!

the last set of bits i bought were from ebay, paid $40 for 36 peice i think (1/32 up to 1/2 in 64ths) cobalt split point. some of the best bits i bought, the ones i use the most (1/4", 5/16", 7/16" and 1/2") are getting dull, but they have gone threw alot of use. i plan on buying a drill doctor to resharpen then. some of the smaller bits have broken, but only because of my stupidity.

Is Cobalt any better or worse than Titanium?

Cobalt drill bits are the hardest steel bits there are. It goes in this order...softest to hardest (1) High speed, (2) Titanium, (3) Cobalt.

Cobalt drill bits are the hardest steel bits there are. It goes in this order...softest to hardest (1) High speed, (2) Titanium, (3) Cobalt.

Thanks 1-ton.

Big83, do you remember what brand the cobalt bits you bought were, and who you bought them from? $40 is about half the price that Sears is asking for the same number of their Craftsmen Cobalt bits. Thanks.

Search here:
http://www1.mscdirect.com/cgi/nnsrhm
and here:
http://www.use-enco.com/
Don't buy the cheap ones!

sorry, i don't. it was about a year ago. ill see if i can find some similar on ebay for ya.

HF stuff is cheap... but for $30, I bought one of those titanium sets. Two, in fact ... if I break a bit, oh well. When it gets dull I put it in a pile to be sharpened on the Drill Doctor. I've not had anything that I needed cobalt or anything more nuclear for.

-- A

this is what i have, i don't think it is the same seller, but its the same drill bits, box and all.
here (http://cgi.ebay.com/29-PCS-COBALT-DRILL-BIT-SET-135-TIP-BITS-POWER-TOOL_W0QQitemZ6028833756QQcategoryZ50383QQrdZ1QQcm dZViewItem)

Cobalt drill bits are the hardest steel bits there are. It goes in this order...softest to hardest (1) High speed, (2) Titanium, (3) Cobalt.

"Titanium" drills are not made out of Titanium. they are Titanium coated High speed or Cobalt drills. usually HSS is used. we coat drills and endmills and cutting tools at my company. the best drills are cobalt drills for general purpose garage use. you can drill stainless with cobalt but you MUST use cutting fluid and drill very slow rpm's. HSS will not drill SS. HSS drills are fine if all you do is mostly wood and soft metals. they will drill steels too but the cutting edge dulls much easier then cobalt drills do.

then there is carbide drills, which are not recomeded for free hand drilling. they are for milling machines and lathes. they stay sharp much longer then the best cobalt does but they can break and or chip VERY easy. the drilling process is a drill chuck or collet holder holding the drill rigid in a machining center like a CNC mill or lathe or a conventional mill or lathe. there is no posibility of side to side movement like freehand drilling with a power drill. you can run 2 to 5 times the rpm with carbide over cobalt and a much faster feed rate because of the faster rpm. get a good set of cobalt drill for home. enough machining drill tech 101 for now. sorry so long i love talking machining, been a machinist for almost 15 yrs. its my cup of tea.

"Titanium" drills are not made out of Titanium. they are Titanium coated

One question I have is: Is the difference between a quality Titanium drill bit and a cheap one...the thickness of the coating of Titanium, and (or) the drill bit material being coated?

Good info from a pro.

One question I have is: Is the difference between a quality Titanium drill bit and a cheap one...the thickness of the coating of Titanium, and (or) the drill bit material being coated?

well it can be both, there are different types of Ti coatings that have different toughness factors and are applied in different thicknesses. also a colbalt drill will allways be more expensive then a HSS drill. another reason for the coatings is to add a factor of lubrisity or slickness to the drill to cut down the heat generated by the friction from the cutting action at the drills cutting edge or lips (yes they are called lips, drill lips)and diameter edge. this aids in the drill from over heating and the material from seing excessive heat. ofcourse a piece of material will still get very hot but without a ti type of coating you will in alot of cases expeirence galling from heat, where base material sticks to the drill lips which compounds the heat being generated. with any drill you should use cutting fluid but a ti coating its almost like having cutting fluid on the drill allready. coatings also make the surface of the tool tougher which adds resistence to tool wear.

speed or rpm is the biggest tool killer along with feed. too much rpm will cause the drill or tool to over heat causing premature tool wear, basically it gets dull. too much feed causes excessive heat and tool load again causing tool wear.

well it can be both, there are different types of Ti coatings that have different toughness factors and are applied in different thicknesses. also a colbalt drill will allways be more expensive then a HSS drill. another reason for the coatings is to add a factor of lubrisity or slickness to the drill to cut down the heat generated by the friction from the cutting action at the drills cutting edge or lips (yes they are called lips, drill lips)and diameter edge. this aids in the drill from over heating and the material from seing excessive heat. ofcourse a piece of material will still get very hot but without a ti type of coating you will in alot of cases expeirence galling from heat, where base material sticks to the drill lips which compounds the heat being generated. with any drill you should use cutting fluid but a ti coating its almost like having cutting fluid on the drill allready. coatings also make the surface of the tool tougher which adds resistence to tool wear.

speed or rpm is the biggest tool killer along with feed. too much rpm will cause the drill or tool to over heat causing premature tool wear, basically it gets dull. too much feed causes excessive heat and tool load again causing tool wear.

Thanks for all of the info. Sounds like i need some Cobalt bits for my general garage stuff. Thanks to everyone who posted for their help!

One more question: Where can I get a Drill Dr. for sharpening my bits, and how much should I expect to pay? Thanks!

What do you guys think of these from Yukon Tool?

http://www.amazon.com/gp/product/B00006F704/qid=1137531024/sr=1-4/ref=sr_1_4/103-6052692-5248643?%5Fencoding=UTF8&v=glance&n=228013

Sorry, I don't know how to do the fancy little "click-here" link paste. :rolleyes:

They are a good run of the mill set. Cobalt coated HSS drills. Here is what Yukon's site says.

115 PCS COBALT DRILL BIT SET Cobalt Alloy coated and high speed tempered. Superior durability over M2 high speed and Titanium coated drill bits. Cobalt will retain a sharper edge and will outlast a standard high speed drill bit by 15 times. 135-degree point design also prevents walking. Cobalt gives added heat resistance making them perfect for all drilling applications, especially cordless drills. 3/8-inch reduced shank to work in nearly any drill. Includes free laminated index guide. The perfect set containing all the drill sizes you will ever need. 60 wire gauge number size bits 1-60. 26 letter size bits A-Z. 29 Fractional Standard Size bits 1/16-to ½-inch in 64ths. 115 total bits in a rugged custom steel index case with built-in organizational folding storage.

They are a good run of the mill set. Cobalt coated HSS drills. Here is what Yukon's site says.

Thanks Muddy. Sounds like a decent set, especially when you consider the price. I'm not a professional mechanic, so I would think that these would be able to hold up for a pretty long while.

I noticed that these are cobalt coated. I assume that when any of these manufacturers claim to have cobalt bits, they are refering to the coating on them, and not the acutual substance of the entire bit. The titanium bits are generally coated bits, so it would make sense that the Cobalt ones are as well. Anyone know if my logic is off?

If you sharpen drill bits the coating is removed. I don't waste any money on fancy bits or coatings. Learn to sharpen bits by hand with a bench grinder and even cheap bits will do wonders. I don't claim I do as good as a drill doctor by eye, but my bits do make nice long curly chips. Save the money and learn to sharpen bits by hand.

It's relatively easy to sharpen larger bits, say 1/2" and larger by hand on a bench grinder, but smaller bits are tou87gh to get the cutting geometry right. You will most likely end up with holes slightly oversize sharpening by hand. Not that it can't be done! I've watched an old timer hand sharpen 1/8" bits by hand and put a split point on them as well. They drilled mild steel like a hot knife thru butter. For what we do with our trucks, a slightly oversize hole is no problem. I am an amature machinist (emphasis on amature), model engineer, whatever you want to call it, and anything but a proprly sharpened drill bit won't work. I sharpen bits larger than 1/2" by hand, the rest go to the drill doctor.

sharpening by hand is an art, yes even very small bits can be done but the smaller the tougher they are. I learned from an old timer with 40 years machining experience, how to sharpen drills by hand. we dont have a drill doctor or industrial drill sharpener here at our shop, so all drills are done by hand. once you get smaller then about an 1/8 drill the price for them does not warrent resharpening them unless its your last one and you dont have a sharp one as back up.

to do a split point the corner of the grinding wheel has to be VERY sharp, not rounded preferably at all. a very small radius is ok for bigger drills but not for small ones. you use that corner to grind the split point. a drill that is sharpened corectly and used corectly will drill a hole the same size the drill is. maybe it will drill big by .002 to .003 thousands but that should be it. if it wallows out more then that its not right.

drilled hole tollerences on blue prints go by the size of the drill. if a call out on a print is for spicifically a drilled hole it will fall into a "drilled hole tollerence" that is usually in the tollerence info block on the print. check this out, go to bottom of the page for drilled hole tollerence.

http://www.engineersedge.com/drill_sizes.htm


granted this is for actual manufacturing. home stuff does not apply. just showing that there is spicific drill tollerences that a stock OR resharpened drill SHOULD drill to. thats what I go by for shop or home stuff.

this is also how you can drill a hole close to size IF you dont have the exact drill you need. it is an old machinist trick to sharpen a drill OFF CENTER or with different length cutting lips so it WILL drill oversize.
you can only do this with in reason. too much off center and it will chatter like hell.

rdn2blazer- I am fascinated by all aspects of machining and appreciate that you are willing to share. Feeds my brain.

Here is a great written description on how to hand sharpen drill bits. This is how I do it. I used to frequent the shooters.com gunsmithing forum when shooters was stil around, teenut was as regular there as 'fumes is here. I learned a LOT from him on that site. RIP


DESCRIPTION:
This is a copy of instructions for hand sharpening drill bits as
originally posted in rec.crafts.metalworking by Robert Bastow (teenut).
Posted by Ted Edwards <Ted_E@bc.sympatico.ca>. Ted provided the
following description:
================================================== ===============
I just posted Teenut's description of how to sharpen a drill by hand
to the dropbox.
Ted
------ 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

WOW! are your fingers sore? thats cool though. I have learned alot over the years and if there is one thing I know is that some people have an ability to learn and understand what you teach them or they just dont get it, and never will. I have helped and shown alot of young guys how to do machine shop stuff. some do great and some just have two left hands and should not be working in a machine shop. sharpening drill bits is one of those things a guy can understand and can learn how to do or he just wont.

Nice write-up Matt! :waytogo:

I've sharpened drills by hand all my life. I generally get "good" results that do the job, but not great, not as good as I wanted. Now I have the Drill Dr 750 and life is good...

Russ, I take no credit whatsoever for the writeup, I just cut and pasted it. But it is excellent.

Maybe I should paste it into a new thread and see if the Boss will make it a sticky?

rdn2Blazer, I'd love to serve an apprenticeship in a machine shop, with non-CNC equipment. Maybe if I ever give up the electrical trade, you can hire me on to sweep yer floors.

The best drill bits i ever used were Dormer split point 135* colbalt. These bits are the best, haven't left me high and dry ever.

i dig the dewalt starter tip bits
work good for me

i love my Drill Doc... but I got one that doesnt do split-point bits... which a lot of the blingin new ones seem to be. Kinda sucks. For any normal bit, the drill doc is money.

j

The best bits for steel I ever had were snap on and I bought them at a yard sale for $2. But I think you would spend over a hundred on new ones.

yeah, I really only need about 3 good bits for steel. If I can cut a 1/4" hole... a 3/8" hole and a 1/2" hole... thats pretty much all I ever really need. Isn't it? Anyone else use a different size a lot on their rig? Maybe I should just invest in the unobtainium uber bits in those three sizes and call it good. :thumb:

j

9/16, 7/16 and 5/16 are very common. 5/8 and 3/4 shows up quite a bit. Then you need other sizes for taps. Just to name a few...

taps? heh, way to bling for my garage. My version of a tap is a nut welded on the other side of a drilled hole. :thumb:

j

taps are a hole nother discussion. there are so many different kind of taps available it not even funny. we use a tone of them in all different sizes. even pipe taps and special taps for titanium. a standard plug tap will snap in titanium. there is a trick to using a standard tap in titanium with out breaking it. there are over size taps, undersize taps, Roll taps also known as form taps, spiral point taps, turbo taps, plug, bottom, two flute, three flute, four flute, coated, uncoated, and on and on and on. they all have there application too. we have just touched the tip of the ice berg discussion on drill bits, and there is just as much about taps too. the crap a machinist has to know.

damn dood... it must be nice to have the tools ya need to get things done. Do you getta borrow from work to take care of projects at home? :grin:

j

damn dood... it must be nice to have the tools ya need to get things done. Do you getta borrow from work to take care of projects at home? :grin:

j

im the shop lead and the only machinist here and I have known my boss/owner since I was about 9. I grew up with his sons. when he had a problem with the old lead guy about 4 years ago he contacted me and asked if I was interested in coming to work for him. he knew my main background was cnc machining and he said you know its not cnc here but if you ever want a job let me know.

well I had got layed off from TRW. they had a 100 million doller satalite project that had just started and they bought a 6 axis Mazak cnc mill/lathe combo machining center and they needed someone to run it. when the project went down the toilet due to over budget they layed me off. so I was looking for another cnc shop. and he asked me again if I wanted to come to work for him. the lead he had he fired after I was here about a year. he had beed here for 23 years. I became lead then. he lets me use, borrow anything I want to. I have been here for 4 years now.

sounds like you are pretty much set for life. I hope you're putting lots of coin into a 401k and/or Roth IRA. :thumb:

j

I do a lot of drilling at work mostely steel, I use HSS and a drill doctor to resharpen. The Drill Docter works great. If you can sharpen a pencil you can use one of these.

The Drill doctor sharpens the HSS easier than Titanium of Cobalt because of the strength of the metal.

To me, the amount that I use the drill bits cannot offset the cost of the more expensive Cobalt bits, and the harder to sharpen Titanium coated bits.