Drilling Titanium, are these drills ok?

[PEU]

Im looking for a not much expensive way to drill some holes in TI (6AL4V) what do you guys think about these kennametal drills? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110284823306
The price is right for a brand name solid carbide drill, but it would be OK?
I know these aren't specific for TI, but the price is still nice...

Suggestions welcomed too

Thanks


Pablo

 

[Anglepoise]

In my experience, the key to drilling Ti is a very sharp drill.

I have an American made HSS Cobalt 1/2" drill that performs beautifully on Ti but I do have to re sharpen often.

I would only consider a carbide drill if I had a good diamond sharpener
or other method to sharpen.

 

[Rothrandir]

I've had good luck with cobalt drills in titanium, granted at smaller diameters. Carbide is said to be too brittle and the extra flexibility of the cobalt drills keeps them from breaking.

At .590 I would be tempted to get an indexable spade drill, but that's not going to happen for anywhere near $45.

Are you lathing or milling here?

 

[PEU]

I plan to use a CNC Lathe. David/Roth do you have links for the drills you guys mention?

A local dealer quoted $300 for a 14.5mm (around 9/16") TaeguTec (http://www.taegutec.com/) indexable drill with 20 inserts, they told me it was a one-time promotion... is the price right? do u have a better deal there in USA?

Thanks!


Pablo

 

[Anglepoise]

David/Roth do you have links for the drills you guys mention?
Pablo

The drills I use for Ti
are made by Union Butterfield.
List # 385.
Cobalt -HSS 135° split point.
For 1/2" size, order # is DOR-4610277
My bricks and mortar retailer want $29.95 each.

 

[Rothrandir]

How many parts do you plan on making and on what type of machine? Horsepower and rigidity can play a role in what type of tool you choose.

I would say $300 for that tool you mention is probably a pretty good deal with the inserts, though I doubt you'll ever use even half of them.

An indexable spade drill is different from the drill you mention. Instead of using 2 inserts it just uses one spade tip bolted to the end. They are cheaper to buy (maybe half or less), and you can change sizes by simply using different sized spade tips. You will not be able to run them as fast though, and do not typically get the chip control like you would with the indexable insert drill.

For anything smaller than an inch, I've always used the spade type, for bigger than an inch I prefer the insert type, as it reduces the power requirements needed. If I had a lot of holes to do in a small size I might consider buying an indexable insert drill for it, but I'd have to first analyze whether or not the investment would pay itself back in terms of reduced cycle time and better chip control. Unless it's a lot of parts, the answer is probably no.

Basically, without knowing exactly what you're doing it'd be hard to make a suggestion.

 

[McGizmo]

Removed. never mind.

 

[PEU]

Basically, without knowing exactly what you're doing it'd be hard to make a suggestion.

A Flashlight...Doh! LOL

Today I went to the CNC shop and I saw what happens when a not properly sharpen drill tries to cut thru titanium even with full pressure coolant/lubricant... poor HSS drill... the more they tried, the harder the TI became... then they used a mitsubishi drill to get past the hardened area, sharpened the HSS drill with a a higher angle at the head (they were sharpening below 100º angle dunno why but I let them know that wasn't OK IMHO) and it machined fine.
But thats OK for a test, not good for doing a run.
Speed is not the main concern, unluckily work is slow these days in Argentina, so if I can find a decent drill at a decent price, it does not matter if you have to drill slowly.
The Lathe? an old and heavy CNC clunker that is properly maintained and works pretty nice (Fanuc control)

suggestions?

Pablo

 

[precisionworks]

Cobalt drills will work well at lower speeds, around 25SFPM, with as much coolant as you can spray in with a pump bottle or with pressure fed (through the drill) coolant. Not the easiest drill to sharpen, but very strong & hard to break.

The spade drill, mentioned by Roth, is very nice whenever drilling from solid. The spade insert is HSS, cobalt, or carbide, often coated, and the drill shanks are extra stout. Always a few on eBay (at least on this side of the pond), in most every size you can imagine. I have them as small as 1/2", and as large as 3". Also available with through the drill coolant hole.

Look at what Allied Machine has, they are the largest USA maker:

http://www.alliedmachine.com/

Or look on eBay under ACME spade drill:

http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=acme+spade+drill&_sacat=See-All-Categories

 

[PEU]

Thanks Barry. Question: Take for example this drill holder from the search you provided:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280301995217

does it work with the other metric sizes from the same search, such as these for example:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250354368105
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360122532915

Thanks!


Pablo

 

[precisionworks]

Pablo,

Each shank or stem will hold a range of sizes. This catalog should help:

http://www.alliedmachine.com/images/library/file/Literature/T-A_Complete.pdf

 

[Rothrandir]

I would suggest a straight flute for lathe work, it provides better chip evacuation.