Thread: Milwaulkee Thunderweb Drill Bits

Originally Posted by Oldneweng

I wonder how Burnsy is getting on with this decision? I hope he has more of an idea than I do.

Burnsy is still going to check them out as I am sure it said Made in Germany on the ones I picked up in Toolmart but in the mean time I pulled the trigger on these
http://cgi.ebay.com.au/ws/eBayISAPI....42654#ht_0wt_0

Bit surprised they passed in the first time listed for auction then relisted as buy it now, $45 to my door, that is not to far off the price of one 13mm Sutton and they look to have never been sharpened and have wood dust on them.

Originally Posted by Ueee

As far as i was aware (could be well wrong though) the TiAN and other coatings are not there to keep the drill sharper longer, but are there to cut friction. These coating materials are generally very slippery and help the bit to spin freely in the hole its created and help get the chips out.

Cheers,
The slightly quiet Ew

Ew, under optimal conditions, TiN coating CAN indeed increase the drill life 3 times or more. TiAN and TiCN can increase the life by 5x and more. This is because the coating is a very hard ceramic material. That is when comparing the same basic drill bit from the same maker, once with and once without the coating. And that is with a properly applied coating, one that typically increases the drill price for an otherwise identical drill bit by 50%. Inferior (cosmetic only) coatings have no real life benefits.

Yes the coating also increases lubricity at the cutting edge and allows 50-100% higher RPM's and feeds to be used. And also reduces edge buildup. But I do not think these benefits alone are the primary argument for or against coatings.

When re-sharpening, all major benefits of the coating are lost. The drill bit almost reverts to the properties of a non coated drill. The rake angle will however in most cases retain the coating and remain beneficial at reducing edge buildup.


PS: I do not own any coated drill sets. I always thought that in a home shop, the conditions to take advantage of coated drill are not present. I tend to damage drills before wearing them out. For example, I do not use flood coolant. For example, when using a hand drill I may damage the drill shaft. Same in the drill press unless I use the collet chuck. Sometimes I break a chip out. I do regrind my drills, some exemplars are 35 years plus old. I do turn over the drill shafts when too badly scored. I aways thought, rather buy an extra spare drill set of the most used sizes, than waste money on a coated drill set.

Originally Posted by Burnsy

Burnsy is still going to check them out as I am sure it said Made in Germany on the ones I picked up in Toolmart but in the mean time I pulled the trigger on these
http://cgi.ebay.com.au/ws/eBayISAPI....42654#ht_0wt_0

Bit surprised they passed in the first time listed for auction then relisted as buy it now, $45 to my door, that is not to far off the price of one 13mm Sutton and they look to have never been sharpened and have wood dust on them.

Nice pickup.

Dean

Hi Guys,
I've only got the coated ones that I posted a picture of ! I can't say I've seen any benefit. After the first use the coating simply disappeared. I've also discovered that only the 6 mm and up are split point All the smaller ones are normal conical ground points.

Originally Posted by BaronJ

I've also discovered that only the 6 mm and up are split point All the smaller ones are normal conical ground points.

I believe its pretty standard for the smaller drills to ground "normally". My imp Suttons I have split point down to 1/8th. Sorry Vipers

Stuart

Originally Posted by BaronJ

Hi Guys,
I've only got the coated ones that I posted a picture of ! I can't say I've seen any benefit. After the first use the coating simply disappeared. I've also discovered that only the 6 mm and up are split point All the smaller ones are normal conical ground points.

It could be a Tin-Cobalt or Zinc-Cobalt coating. These are used instead of Cromium plating to increase corrosion resistance.

It could also be electroplated Acolyte, it is indistinguishible from a Cromium plating. They would just do it to put the word "Cobalt" on the box.

Caswell has such a diy Cobalt plating kit:
http://www.caswellplating.com.au/sto...-is-Cobalt-Kit

These are all coatings for appearance or rust protection, not really of any advantage for a drill bit other than for the "Cobalt" name on the packaging. These coatings would quickly wear off in use.



There is a Tungsten-Cobalt coating system. It is a Tungsten Carbide coat embedded in a Cobalt substrate. It is applied by sparaying. It is used to increase life of forming tools, not drill bits. Also to coat hydraulic pistons, valves, pump parts....
http://www.thermische-beschichtung.d...id-kobald.html



There also was a scam in mid 2000 in France, Germany and Switzerland. French speaking fraudsters were visiting metalworking shops, and offering to resharpen and "Cobalt Harden" used tools
http://www.messerforum.net/archive/i...p/t-29104.html

I have just ordered a set of 25 metric Thunderweb drill bits from Get Tools Direct. They cost nearly $59 including insurance, although I am not sure if the insurance is of any value. I sent a package by registered post once and when there was a question of whether it had been delivered, all AusPost could say was they had received a signature. That was it! The signature registered the fact that the parcel had been received by "a person". That was the sum total of the help from them.

The set of Thunderbolts that I have contains 29(?) drills including several inbetween sizes extra such as 4.2mm and 6.8mm. The Thunderwebs only have 25 drills in 0.5mm steps.

Dean

You should be able to confirm the origin before I get a chance to get to toolmart. Please post a photo and details when they arrive.

Originally Posted by Burnsy

You should be able to confirm the origin before I get a chance to get to toolmart. Please post a photo and details when they arrive.

Ok. I will do that. Hopefully they will not take too long to get here.

Dean

Hi Oldneweng,

Originally Posted by Oldneweng

The Beryl Bloke. It seems that coated drill bits are not much use for the home workshop.

Dean

Generally, I doubt that they do much for a home workshop. Sometimes, maybe. When we put the roof on the shed the roofer had a very difficult time getting the roofing screws through the colourbond and the purlins. I gave him a few TiAlN coated, cobalt jobbers to drill pilot holes. He was most impressed with them. Given he was using battery drills, I'm thinking that the actual cobalt bit and it's geometry was what made the difference compared to normal HSS. A battery drill probably can't get that coating hot enough to work properly.

I had a closer look at the poorly performing TiN coated, split point, parabolic drill I mentioned previously. The "split point" was more of a relief grinding at the back of the lip. Those relief grindings did not make a split point. This drill came as part of a bunch of stuff I picked up off ebay. I was a bit dubious about it at the time. A "no name" extra long, split point, parabolic TiN coated, 8.5mm drill for $4.50.... hmmm..... what's wrong with this picture? other than lots!

So... Sometimes I think that premium drill bits with exotic geometries can be useful in the home shop. The fact they come with pretty coatings may be of no value to you other than rust prevention. That said, if you are working almost exclusively with steels of average strength, seldom drilling deeper than one drill diameter, then a set of good HSS jobbers probably will do the job just fine. In that regard Chris's (cba) approach has much to commend it. It's not an approach for me. My plans are towards building capabilities for small production runs in Stainless and Titanium, among other things. I don't wish to retool along the way. Then again my plans and aspirations probably fall somewhat outside what most people would call a home workshop.

Cheers

The Beryl Bloke

I just ordered a set of these:
http://www.ebay.com.au/itm/Heller-19...item3f3488f091

They are 19 genuine German made Heller HSS-Co5 Cobalt drills, fully ground and with split point, uncoated. Heller is a less known German maker near Bremen. They seem to me good value at about $82 including postage from UK.

http://www.hellertools.com/taxonomy/term/6

Interesting thread.
I bought a set of drill bits coated yellow (cobalt? really?) from Aldi. I can not remember the price I paid for the box of 20 bits but it was less than I paid for a pair of so called boat shoes. Nice shoes I use to go to work, and not to go on my boat since I think on a boat you keep on, only what you would be able to swim with.
So my box of $30 or so drills turn out to be $1.50 per drill bit.
Are we seriously debating and exchanging words over $1.50 drill bits?
It would make way more sense to debate and exchange heavy industry related standards about my $40 (or so) boat shoes.
No it wouldn't, and neither does it to debate industry standards on such cheap drill bits made in Germany, Macedonia or Mongolia.

The drill bits I bought are of a very decent quality as far as I can determine, after drilling 10mm plate on my 3hp drill press I use with mercilessly downward pressure.
if a drill snaps and is too short to be sharpened again it ends up in the bin. If a bit is too soft and loses the edge more than once in the day, it ends up in the bin. When my shoes develop a hole from walking or a stain that does not polishes off, they end up in the bin.

I understand debating a bimetal $600 brick saw cutting blade, not a $1.50 drill bit.

But hey, that is just me.

We got a set with the last Milwaulkee cordless purchase the shop made.

Seem to go fine; havent killed any to date.

No better/worse wrt holding their cutting edge then the Sutton stuff on the bench.

Originally Posted by Marc

I bought a set of drill bits coated yellow (cobalt? really?)

I always thought the "yellow coated" was titanium nitride?

Stuart