Drill Bits Titanium or HSS- G !!

[Kiriakos-GR]

The experts  at metal work, or hobbyists who loves quality , will know the answer.

Let us know too, what you find as " seriously worthy " product ,
at the years 2007 - 2010 ..  

My need its just precision , and lasting ones ..
As I drill mostly aluminum , and metal up to 4mm max .

So in order to update my bits , I am looking for a set .

[A-sic Enginerd]

titanium is sweet, but there are potential issues.
I've seen cheep "titanium" bits that in reality are actually just titanium coated. Also seen some that just the tip is titanium. The issue with both of these is - if they ever need resharpened, yer screwed. If they are true titanium (or alloy) through and through, they are nice, but usually cost prohibitive. I've never even attempted to resharpen one of these so I don't know if there would be any sort of issue or technique to it.

From the sounds of things, I'd just go with HSS.

Oh, and by 'precision' be cautious of what you mean by that. In my former life I was a mechanical tech which means I spent my days doing machining, fabricating, welding, etc. For me, anything that even began to approach precision was +- 0.010" as absolute worst case. And no, you can't get that with a drill bit. They are too sloppy and wander. If you truly need that precise you need to start looking at reamers and such.

[Kiriakos-GR]

Thanks for the advices , and I agree with you in all .

I ended up to the new line called as HSS-G  DIN 338.

10% cheaper than the know brands with Titanium coated .
But still expensive in comparison with common HSS.

This new generation of Drills offers lots of advantages.
But I will not get in detail .
Internet can offer all the details, to any one with interest about them.

My immediate need are to drill aluminum , by the most perfect way,
so all holes , to be as much centered as possible , even by a power drill on base ,
that I do have one.
Plus , the drill cut " sides " , to be perfect, so to avoid extra labor of finalizing the hole with hand tools.
And last wish ...     to be good quality and last for years, thats why I usually buy tools that are considered as an overkill for the job.


The only brands widely known , that do have HSS-G , are BOSCH - DEWALT - HAWERA .
My shopping experience , was a bit of tragic ,  I had lots of years to go for shopping for such tools.
Even if I got , an product of a brand known to be as German ... I did not make it , to avoid the logo .. Made in China.

Even if the specific drills, are an masterpiece , my moral are damaged , because I belong to the old school,
of technicians ..   ( with plenty Chrome-vanadium made in Germany tool cases )
Crop of the cream , in the European market .

From my ultra fast seminar , on drills , I discovered and the special board of the specific rpm by drill size,
something that had never bothered me before , as my power drill on the base , turns with 500/600 rpm per min.

But now , I must seek for an rpm meter so to check my portable Toshiba,
that has electronic adjustable  speed control , and lots of rpm ..

Some pictures of my new set ..
Priced almost reasonably in my country and EU , with average street price 28EUR  or  36 USD.
And as highest 38EUR = 49$  

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[Kiriakos-GR]

First Picture .. HAWERA  ..

Other two , the same product circulating as BOSCH .

It looks that the Chinese maker , it does a good job,
and so it earned the cooperation of two famous brands !!


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[cybergibbons]

I've never heard of titanium or even titanium alloy drill bits, neither material lends itself to use as a cutting tool.

You do get titanium nitride coated drill bits - if you get decent ones, the cutting edge will last a lot longer than normal HSS bits. This is especially true when using big (10mm+) bits on awkward materials such as stainless. That said, you'll generally sharpen the bigger drill bits anyway, so unless you need the bit to last longer between sharpenings, just get the HSS.

You also get bits with brazed on tungsten carbide cutting bits - these are very hard and long lasting, but don't lend themselves to use outside of precision machining as they are very brittle.

PCB drills are frequently pure tungsten carbide.

[cybergibbons]

Also, if you want a good hole in aluminium, follow these guidelines:
* Support the work on MDF or another high density wood
* Clamp the work as aluminium sheet is prone to grabbing. You also need to stop the plate lifting from the support, which causes a dent on the underside. If I'm working with thin sheet, I drill a slightly larger hold in a piece of MDF and clamp that down on top of the sheet.
* Drill a pilot hole - make it about 1.5 times the width of the chisel edge on the large drill (the chisel edge is the flat bit at the point). I find you can judge this size by eye.
* Use light pressure and a slightly slower RPM than you would use on steel.
* If you have a choice of drill bit or can sharpen your own, chose one with a point angle of about 90 degrees (i.e. more pointy than normal) and a higher lip angle than normal (20-25 degrees)

[Kiriakos-GR]

Those are correct advices for standard HSS , and I do follow most of them , as you had described.

But I got more in to the specs of those special type drill bits, and found that they do not need an pilot hole at all .
They use an special  by BOSCH patent,
by reading this I found and the marketing connection,  BOSCH own the factory in China ,
and shares the goods with HAWERA .

More technical info here ...
http://www.hawera.com/hawocs-en/Category.jsp;jsessionid=8309B0BEC950576F67DD878A6759F076.s036-tc6?ccat_id=100913&lang=en

And I will share one tip with you too,  on aluminum  keep the common HSS drill bit wet,
all the time with alcohol.  

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Edit : on the above link  it says

excellent surface quality due to special factory standards

In the same page in Greek  ... says clearly by BOSCH ..
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[A-sic Enginerd]

Alcohol huh....ok.
I've used cutting oil, but never a solvent.

Best trick you can do to keep your holes where they need to be: hit it with a center drill first. Doesn't have to be much. Just enough to make a dent / divot in the material. No matter the make or flavor of drill bit or what kind of point it has - it's a long spindly thing that's trying to start cutting at the point. This means it's going to wander. Center drills are short, stout, and wont flex. They'll mark the hole exactly where you initially line it up to. Then this gives the drill something to follow.

[Kiriakos-GR]

Alcohol  keeps the aluminum cold.
Plus keeps the aluminum away , from becoming one body with the drill ..

I just got one rpm laser counter for 10EUR  12$ ,
so I will have full control from now and on.

Thanks for the help .

[cybergibbons]

Surgical spirit is actually quite a good cutting fluid for very light final cuts - you can get a really good finish. It only really satisfies the requirements of cooling and swarf clearing, there's little to no lubrication. You also need a good flow of it - it's no use just brushing it on.

[Time]

Due the to the thermal process that is evaporation, anything that evaporates quickly might prove useful for heat transfer.  Alcohol would be a good coolant due to its low temperature of evaporation but I am not sure about its lubricating properties (lubrication properties mean less heat production while cooling properties mean better heat transfer).  There are alot of variables that are dependent on the application.

If you are just milling simple 2 oz copper boards for prototyping you can easily get zirconium tipped bits that will last forever if you don't decide to abuse them.

[GeoffS]

I use either kerosene or WD-40 as a lubricant when drilling/milling/turning aluminium. I rarely find heat to be an issue if you use the correct speed.
HSS bits are all you need, TiN coated bits are a waste for this type of work.

As previously mentioned, be sure to clamp the work piece down to prevent lifting.

[MTron]

Time and cybergibbons are right on the money, the Alcohol only serves to cool via evaporation. Generally, Aluminium (depending on the specific type) doesn't need much lubrication, especially with just light work, clearing chips with some compressed air is often enough with 6061T6 Aluminium, depending on the depth/type of cut/drill.

Personally i just use a squirt of WD40 and keep the cutting speeds low. If you can get a nice long spiral chip coming out, your doing well, and the drill is cutting good and you're applying good pressure with good speed. I aim for a 1 inch long chip or so, then back off, then reapply... ie Peck Drilling (making sure to clear chips in between)

As for the drill bits. If you're looking for something quality, that will last (especially if you take care of them) and don't feel like jumping to carbide, look for a good set of Cobalt Drill-bits, they are somewhere in-between HSS and carbide.

I stay away from the generic Ti coated bits,  if you got them from a reputable manufacturer then go for it, but only if you can corroborate their claims of quality. The ones i have run into most often are just cheap bits with a substandard coating. I have had better results with good quality HSS bits then cheap Ti coated bits

Now that being said, a Ti coated bit, is technically superior for drilling aluminium. The Ti coating lowers the coefficient of friction of the bit, and doesn't heat up the aluminium as much which prevents binding or the aluminium welding its self to the bit. If you can find a quality set of Titanium coated bits, from a reputable manufacturer and a good price, i say jump on it.

also, A-sic Enginerd is right. Doesn't matter what drill bit it is, it will "walk" when you first plunge it. Even if you get superb "non walking" bits, there will be enough horizontal lash or play in your drill press quill, that you wont get a precise hole. Get a center punch, give it a little tap or two, and your drilling results will increase dramatically. Also, you could purchase a "center drill" which have hardly any walk whats so ever, as u will see why when u look at them, the "bit" part is only about a centimeter long, and the body is very thick and are only used to drill very thin pieces or to start a hole. I find these useful for drilling big holes. I center punch, drill it out with a center drill, and drill to the correct size with a HSS or cobalt drill.

[Kiriakos-GR]

About WD40 , due the fact that it has petrol in it , it damages the hardness of the drill bit.

I got special industrial lubrication fluid .
That machinists use all the time.

[Anamie]

I know it's an old thread, but maybe it will be a timely resurrection for someone

High speed steel is good for anything from wood to titanium, why titanium you ask...its beacuse the high speed steel takes te heat where carbide will cause work hardening and snap a drill very fast if the piece gets warm. Their are alot fo variables on this one but high speed steel is a great general purpose steel for drilling/milling


Cobalt~ cobalt is a very tough material but extremely brittle and when mixed with HSS it creates a very tough drill second only to carbide good for everything from wood to harder steels

Carbide~ there are many different types of carbide with micrograin carbide being the toughest and couple this with coarbonitrate titanium and other titanium coatings and you have a very formidable drill that is capable of drilling most any material, Concrete drills use carbide tips and hardened steel bodies with the carbide brazed on the body, this provides a very tough drill that can take the pounding and not chip out. Carbide drills are usually 3 times heavier than HSS

Diamond~ Diamond is used for cutting concrete and for holding tight tolerances in high speed machining of aluminum and softer metals, When i was at 3M they actually invented a machine that makes industrial grade diamonds, it was so efficient that GE asked them to stop producing diamonds. The Machine that looks like a alien bomb still sits in a dusty room to this day at 3M's center in Oakdale MN. Diamond or diabide is coated onto drills and adds a very thin layer of diamond buildup that last a long time in abrasive conditions. Diabide cannot take heat and the coating crumbles off when cutting harder metals.....its kind of a bummer we can use diamond on our cutters but cant cut anything hard. Also industrial diamonds are used on concrete blades and are visible by little black dots and raised dots on the blade.

Drills come in many different sizes and qualities with chinese drills leading the pack of cheap disposable drills that dont hold an edge very long, so is true for carbide and cobalt drills, you get what you pay for..usually if you go to JandLindustrial.com theylists all their tools as either import or domestic. Machinists know the difference between import and domestic tooling` Import tooling wears out too fast but is a great substitute when setting up a production job where you may break a tool or 2.

Also drill technology has come a long way, companies likeAllied offer a psade drill like this best cobalt drill bit sets for hardened steel that takes a insert made out of micrograin carbide and coated for the application. these drills are sweet but arent for your average consumer. Here is a little info if you are going to sharpen your own drills at home

1. 118 degrees is your standard drill tip angle
2. 135 degrees is usually used on a split point drill where you are not using a center drill to start the hole.
3. Keep in mind the relief on the top of the drill and on the side!!
4. Drills usually are only sharpened 8-10 times in a machine shop as the inner web gets thicker and is tapered the drill looses alot of efficiency
5. Drills are also prone to the side flutes wearing, it is possible to resharpen a drill and it may look good but not leave a good finish in thehole or leave a galled or reduced diameter.
6. Remeber that you can sharpen a drill back to spec but if you spin the drill in your chuck youve probly damaged the shank and the drill will not hold a on center rotation with a damaged shank.


good luck with your drills guys and if your hand drilling with a old drill make sure your bracing yourself or slow down at the end of the hole

[TERRA Operative]

I like cobalt drills. Awesome for when you need holes in stainless steel.

[coppercone2]

If you want to center a hole for real use a center drill to make a pilot hole.

Then ream the hole when you are done if you want it to have precise dimensions.

if you need to mark it out by hand, use a carbide scribe to make a X precisely where you want to drill, then get a very light sharp punch and align it based on feel (not visually) of the X groove, then make a small dent, switch to a automatic punch or a hammer punch, then go to center drill. Do all the layout on a flat hard surface and make sure your punch is aligned vertically when you make your punch hole.




Not only does he show you how, he measures his results, so you know what you can acheive.