Titanium Drill bits

From: Purple	18/04/2000 22:53:00
Subject: Titanium	post id: 59008
These ads that are on at the moment - titanium drill bits - are they for real?

From: David	18/04/2000 23:05:00
Subject: re: Titanium	post id: 59017
They won't really help a lot. Once you wreck the tip that's it. With HSS drills you can just resharpen them on a bench grinder and you're away again. If you're drilling metal the best thing to do is drill a pilot hole the same diameter as the flat bit on the end of the big drill and the big drill will go through it like a hot knife through butter.

From: Alan™	18/04/2000 23:07:00
Subject: re: Titanium	post id: 59019
I haven't seen these adds. I suspect they are refering to titanium nitride coating on a steel bit, rather than an actual titanium bit. Off the top of my head, there would be no advantage using titanium. They have similar strength, but a third of the weight and much more expensive. Titanium nitriding coats the steel with a very high wear resistant. This means that the bit would retain its sharpness for longer. Lots of cutting tools have this coating and many other purposes, looks like either a dull gold colour for a poor quality coating or bright shiny gold colour for a high quality.

From: Purple	18/04/2000 23:08:00
Subject: re: Titanium	post id: 59022
I was wondering if their claim of never getting dull was correct. Would coating with titanium mean the bits would never get dull? Thanks David but I leave the drilling to the MOTH (unless I'm in a "I am woman" kind of mood)

From: Purple	18/04/2000 23:09:00
Subject: re: Titanium	post id: 59023
Alan - its one of those "you want more?" kind of things which is why I was sceptical.

From: Spazgaz	18/04/2000 23:11:00
Subject: re: Titanium	post id: 59026
I would suggest an advertising ploy. What would the 'normal' person who would bbuy drillbits think? The store has normal one's and slighty dearer titanium tipped one's. They would go for the titanium one's, as they sound better, stronger, higher quality... "Titanium tipped? You pay for quality you know." Thanks. SPAZGAZ

From: B.C.	18/04/2000 23:20:00
Subject: re: Titanium	post id: 59035
Titanium tipped or coated drill bits are made primarily to drill through harder metals,e.g.stainless steel or through metals that have been esspecially heat treated

From: David	18/04/2000 23:22:00
Subject: re: Titanium	post id: 59039
With all drill bits they are specially shaped with a tapered trailing edge. Once this gets a bit out of shape your drill is blunt. The titanium won't stop that happening or even really slow it down much. That's why you should drill a pilot hole - it WILL stop your drills from blunting. It is normally heat that deforms the cutting edge/trailing edge so titanium may slow the blunting down a little but if you are drilling a 1/4" hole through 6mm plate it is going to get HOT and your drill will get blunt before you get through. All in all they would be a waste of money.

From: Bruce D ©	18/04/2000 23:23:00
Subject: re: Titanium	post id: 59040
I use both the titanium nitride and the cobalt coated drill bits all the time. They do work especially when drilling metals like stainless steel or other harden steels. The coating on the bits do wear off and at that point, you should resharpen and use them as High Speed Steel bits. Unluckily the bits are more easily broken, a factor of the tensile strength of the material the drill is made from. I would be very wary of the ones advertised on TV as they are too cheap.

From: Alan™	18/04/2000 23:24:00
Subject: re: Titanium	post id: 59041
It would be difficult choice actually Purple. Titanium nitriding would definitely extend the useful life of a bit. But they will eventually become blunt. I tend to snap the bits or have them corrode. This is because a use hand held drills and work work in a marine environment. If however you are using a drill press, I'd probably use them, if they were good quality. Now if I could get them titanium nitrided by the process developed by the CSIRO and the Australian Mint, which gave absolutely fanastic results........

From: David	18/04/2000 23:24:00
Subject: re: Titanium	post id: 59042
With all drill bits they are specially shaped with a tapered trailing edge. Once this gets a bit out of shape your drill is blunt. The titanium won't stop that happening or even really slow it down much. That's why you should drill a pilot hole - it WILL stop your drills from blunting. It is normally heat that deforms the cutting edge/trailing edge so titanium may slow the blunting down a little but if you are drilling a 1/4" hole through 6mm plate it is going to get HOT and your drill will get blunt before you get through. All in all they would be a waste of money.

From: DAZZA	18/04/2000 23:31:00
Subject: re: Titanium	post id: 59047
if you are talking about those drill bits that drill sideways as wel, I never saw them demonstrate that on anything stronger than perspex or chipboard. I imagine that they would n't last 10 seconds when cutting sideways through metals. If you only use them in a drill press to drill through materials which are clamped, I assume they would have a longish life, but in real life this isn't always the case. Ah the wonders of television! If you go to a tool store you can buy titanoum coated drill bit and they cost a lot more than the ones advertised on TV, there may be something in that.

From: Purple	18/04/2000 23:31:00
Subject: re: Titanium	post id: 59048
Thankyou everyone :o) and for once I have an idea of what you're talking about :o) :o) I did engineering science year 11 & 12 (AND I was the first girl in our school to do so) so I understand (a little) about tensile strength and hardening etc. Maybe I won't jump off the shed after all....

From: Alan™	18/04/2000 23:46:00
Subject: re: Titanium	post id: 59058
With titanium nitriding you should be able to get a minimum 2 - 3 times the life maybe even 10 times the life. A lot depends on how well bonded the coating is on the surface and how smooth the surface is. The standard process involves the vapour deposition of the coating onto the surface. This is assisted by using charged particles and giving the work piece the opposite charge. The process developed by the CSIRO and the Mint, was able to bend the beam of charged particles (just like in a spectragraph unit). This meant that the particles which were too small or too large, were rejected. And the particles hitting the work piece were evenly coated and the surface (at microscopic level) was smooth. They have reported extending their die lifes at the mint by up to 100 times, where before it was only about 5 times. * figures based on distant memory

From: Dr. Ed G (Avatar)	19/04/2000 0:39:00
Subject: re: Titanium	post id: 59079
Was this using a cathodic vacuum arc, do you know? Or ion beam sputtering? Or filtered laser ablation?

From: Mike MGB	19/04/2000 1:22:00
Subject: re: Titanium	post id: 59094
As has been mentioned there are coatings and thereare COATINGS. The price of Titanium nitride or simmilar coatings is coming down and is now rather cheep in Europe. The real price difference is more than likly to be in the steel that the bit is made from before coatins. Good drill bits are usually made from High Speed Steel (HSS) or Cobolt HSS (HSS Co) but cheep drills are made from carbon tool steel. Once coated there is not much difference in apperance and you need expeeeriance to tell the difference. The side drilling is not new and i have some dits from the 1950's that are designed for this.(they are used in furniture making). All in all i would recomend going for a resonable HSS drill and get a pamphlet on how to sharpen them by hand on the bench grinder.

From: Min-Zhao Lee	19/04/2000 21:42:00
Subject: re: Titanium	post id: 59477
And what's wrong with the hign-temperature diamond deposition? Or, to get right down to basics, tungsten carbide? ...boron nitride... ...silicon carbide...

From: Dr. Ed G (Avatar)	19/04/2000 21:46:00
Subject: re: Titanium	post id: 59478
I believe some of the problems with diamond on steel include the solubility of carbon into steel, getting even coverage around odd shapes (like drill bits), and compressive stresses in the diamond coatings which lead to poor adhesion.

From: Min-Zhao Lee	19/04/2000 21:49:00
Subject: re: Titanium	post id: 59482
Fair enough. Obviously I don't know enough about the deposition of diamond onto surfaces. I only read about the concept.

From: Dr. Ed G (Avatar)	20/04/2000 1:25:00
Subject: re: Titanium	post id: 59626
Well it is a thriving subject of investigation but I don't think anyone's actually dep'ing diamond on a large scale. Although they are using a related material, hydrogenated amorphous carbon (which I'm currently trying to co-author a book on) coatings as a low friction, low wear, coatings on hard disks and Mach 3 disposable razors. Soupie twist, Ed G.

From: Dr. Ed G (Avatar)	20/04/2000 3:34:00
Subject: re: Titanium	post id: 59637
I curious factoid related to that (well, not very) is that apparently for men it takes on average 3 days for a razor go start to go blunt... but this has nothing whatsoever to do with the sharpness or wear resistance of the blade... that's just how long it took before users felt that their razors were going blunt - i.e. it doesn't correlate with any objective measure of sharpness.

From: bob s	20/04/2000 7:55:00
Subject: re: Titanium	post id: 59646
I believe that titanium cabide tips are used un drills as an alternnative to tungsten carbide. The only way that I know of to deposit diamond on steel is to electroplate another metal (cobalt) onto the steel and with the electroplate, diamond powder. This is a commercial process. The tools made by this method are used for cutting ceramic materials with cooling water applied constantly. You can purchase diamond coated nail files made by this method. Also available are hot pressed pieces of metal with included diamond or a mixture of diamond and tungsten carbide. This material is used as tips for tools like saws or coatings for gringing wheels. Diamond tools must be used with cooling water.