Riveting titanium

I’m working with 26 gauge titanium, and have worn out several drill
bits while drilling holes in it for the rivets. Can anyone recommend
a brand of drill bits or burs that will withstand titanium’s
hardness? Thanks!

Emie Stewart

Welcome to the delightful world of titanium :slight_smile: Cutting titanium is
very hard on tool cutting edges. There are no simple fixes like a
particular brand or tool material. If you are using tools like a flex
shaft or inexpensive drill press you best bet is to stick with high
speed steel drill bits, they will give the most bang for the buck and
are most able to tolerate out of spec speed and feed use. Carbide is
wonderful if you run it at the right speeds and feeds with a very
ridged setup but the slightest bit of movement in the work while the
drill is in contact with the work will fracture the carbide bit and
they are way more expensive than the HSS bits. You are going to be
best served if drilling a lot of holes in titanium by getting set up
with a good drill press and a ridged way to hold your work. Then you
need to get the correct speed and feed data for the drill bit size so
you will be able to get maximum life out of your drill bits.

James Binnion
James Binnion Metal Arts

I'm working with 26 gauge titanium, and have worn out several
drill bits while drilling holes in it for the rivets. Can anyone
recommend a brand of drill bits or burs that will withstand
titanium's hardness? 

Carbide bits help, and lube is essential. Also, a fairly heavy feed
pressure and slow speeds seem to help too, so the bit is cutting
deeply into the metal, rather than skidding over the oxide layer.

But for the holes needed for at least small rivets, have you tried
some version of a hole punch? 26 guage is thin enough that it would
seem to me that some of the hole punching pliers or other hole
punches might be the way to go. I’ve got a Chinese made copy of the
old Roper Whitney punch design (Harbor freight, about 15 bucks, or
other sources, such as Contenti, also now carry them) that goes
through thin titanium just fine. If they get dull, you can sharpen
them easily enough too. They come with a center spur to help locate
the hole on a center punch mark (also helps clear the slug from the
punch), but it works just fine with that ground off, as in
sharpening the whole face for a flat end punch. That also gives you a
means to produce small circles if you want.

Peter Rowe

Hi Emie

I do a lot of drilling of titanium, up to 10mm deep with 0.8mm drill
bits. I don’t recommend any size smaller than 0.8mm.

Any good jewellers drills should do (I don’t recommend HSS, more
cost for little added benefit).

Preferably use a precision bench drill. The secret is little
pressure applied in gentle pulses withdrawing the drill bit almost
completely to clear the swarf out. And the generious use of a
lubricant such as ‘magic cut’. Oil is ok. Oil of wintergreen, the
smelly oil in the stuff put on aching muscles. cant remember the
chemical name.

Buy a medium Easy Lap diamond hone and learn to sharpen your drill
bits before they break. Have a look at a new one through a strong lens
then try to get the angles correct on an old drill bit. Hold the drill
bit tip against your bench pin and file with the diamond hone. It is
a bit difficult at first, but using a strong light to bounce off the
facet you cut enables you to see clearly.

I can use the same drill bit for 20. 0.5mm holes. If the tip of the
drill gets discoloured you need to grind off all the coloured part
before re sharpening.

David

Lube, agresive feed low Rpm. HSS or cobalt drills count but are not
needed. Ti is tough but as evil as some folks pretend

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand

Hi Emie,

It’s not that Ti’s hard. It’s not. The trouble with it is that it
doesn’t conduct heat well. This keeps the heat from drilling right
at the drill point. This causes the drill to anneal itself, and wear
out. It looks like the metal’s too hard, but what’s really going
on is that the heat’s annealing the drill bit.

The solution is to use slower speeds, press harder than you think
you should, and use a lot of lubricant to carry the heat away. (I’m
fond of liquid burr-life myself.) A drill press is definitely a good
idea if you have one. Depending on the size of the drill bit, you
could snap it if you press hard, so be careful. If it’s under about
1/8" diameter, don’t press hard, just run it slow with lots of lube.

FWIW,
Brian.

(I don't recommend HSS, more cost for little added benefit). 

Virtually all drill bits sold in the US are some form of HSS and
have been for many years it would take some looking to find plain
carbon steel. Now cobalt or some of the other fancy HSS bits are not
needed but if you are drilling at the right speed and feed you will
get the extra life to justify the cost on cobalt.

James Binnion
James Binnion Metal Arts

Maybe punching holes would be easier - titanium is easier to punch
then to drill.

From year of experience drilling steel (and a bit of titanium) I can
tell you that the brand or type of bit does not make as much
difference as lub and the right speed. With hand drilling its so easy
to ruin your drill bit in a burst of speed that makes the end dull
and useless but it still looks about the same to the naked eye
(sometimes with heat coloring at the tip).

Jon Daniels
The Ring Lord Chainmail

When we talk about metals, we need to keep in mind that there are
many alloys of each available, the same is true of titanium. I
generally use a CP1 Ti, a reasonably pure alloy (there is always a
small percent of impurities). It is a soft, sticky metal that is
easy to drill (for sheet at least). There are also some hard and
tough alloys like the common Ti 6Al 4V, which is said to act a lot
like 300 stainless. The CP1 has a reputation as a better metal for
anodizing, and I find it very reasonable to drill, saw, press form,
chase etc. I think the biggest thing is to keep the drill lubricated
and cool enough so it does not lose temper and so the Ti does not
"weld" itself to the drill bit edges as you drill.

You need to control the drill pressure to ensure enough bite to
remove metal and not just spin on the metal.

Marlin

In another life, I used to have to punch holes in heavy flat, Hi
Carbon springs for reassembly and repair when they were broken. I
was taught to use a small hard steel FLAT END punch of the right
diameter as the hole wanted. Another name for that type punch is
called a “Roll Pin Punch”. I expect that an old burr with the head
cut off would work. Do not draw the temper when you cut the head off.
Small short sections of hard spring tempered steel rod as available
at model hobby shops will work… This is available in 36 inch lengths
and are inexpensive. I expect a small silicon carbide wheel in your
flex shaft would work. I would try a 1/8 " (0.125") size first. A
wooden stick or 1/2" FLAT metal holder with a 1/8 " hole drilled
through it will hold the metal rod. THE ENDS OF THE ROD MUST BE
STRIGHT, FLAT, AND HARD.

The real trick is in using 24 inch sections of the hard seasoned
bottom sections of an old Oak wooden pallet. ( A pallet is a short
wooden platform that things are stacked on so a forklift can pick
them up, and its supported load, to load on to trucks.) these can be
had for the asking at place which uses trucks for shipping. Get one
piece and cut it up into 24" sections. Sitting on a chair with the
hard wood stick between your legs, you are ready Now place the
Titanium on the small cut end. This small wooden end is called the
end grain. Hit the short piece of spring steel or steel punch and it
will punch the hole. YOU WERE WEARING YOUR SAFETY GLASSES
RIGHT? YOU BETTER !!!

Use a 1 or 2 pound hammer to strike the 1/8 " rod. Flip over the
piece and flatten the slight dimpled side.

The first part is cheep, the second part is free. You can even do
this sitting down. You can’t beat that !!!

In a episode of Star Trek, Kirk and Spock are trapped in the past
and are forced to use primitive means to accomplish hi tech jobs.
Spock made a comment about having to use flint tools and bear skins.

Welcome to the New Neolithic !
ROBB. ( RETIRED OLD BABY BOOMER )