Page 1 of 2 12 LastLast
Results 1 to 15 of 23
  1. #1
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default Making titanium pens

    I've ordered some titanium solid round in 8 and 10mm with the intention of trying my hand at making a few pens as give-aways. I think the pieces I've ordered are of the better grades for machining (6-4 and 3-2.5). I have plenty of carbide tooling, so I'm not too concerned about turning the outside of the pens. However, I am concerned about drilling the hole through the pen. I'm going to use a D1 pen refill which is 2.3mm in diameter and 67mm long.

    My proposed design is a straight-sided pen with a screw-on cap. It would be drilled to take the D1 refill. The end would be drilled and tapped to take a brass tip that holds the refill in place and provides something for the cap to slip or screw onto. Something like this:

    Ti pen.png

    I believe heat build-up is the main problem with Ti as it has only one quarter of the thermal conductivity of steel. I don't have flood coolant.

    I've got some Q's I hope someone can answer:
    • Before I destroy a bunch of HSS drill bits, should I bite the bullet and get solid carbide drill bits for the job?
    • Any precautions required when using taps?
    • Any other tips for working with Ti on a small lathe (Hercus 260)?


    Cheers,
    Chris
    Chris

  2. #2
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Chris,

    I've never worked with Titanium either But I would definitely go with carbide tooling, both drills and taps. I understand that it is a very tough material, a bit like stainless steel. I don't know what lubricant you might need for machining, but I feel that you will need something.

    JMTPW.
    Best Regards:
    Baron J.

  3. #3
    Join Date
    Jul 2012
    Location
    Griffith NSW
    Posts
    435

    Default

    Perhaps a gun drill? My concern for the drill material is secondary to your chances of getting that hole to be remotely straight, especially when youll struggled to keep a hss drill sharp for that length of hole. A gun drill with a carbide tip would have a much better chance of making it down the other end with anything resembling straightness.

  4. #4
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    Thanks gents. Gun drills seem to be exy. Another option might be to drill 5mm all the way using one of these:

    https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

    5mm is the tapping drill for a M6 tap. The price is right.
    Chris

  5. #5
    Join Date
    Jun 2008
    Location
    The Whitsundays
    Posts
    229

    Default

    Hi Chris,

    Titanium can be worked on Sherline lathes, so your Hercus should be fine.

    The material work hardens so speeds and feeds are important. It also galls (like aluminium and stainless).

    A 67mm deep hole for a 2.3mm drill is nearly 30 times diameter deep. It's still over 10 x deeper than a 5.0mm drill. Whatever drill you buy, make sure it is rated for that depth of hole. A Cobalt drill with parabolic flutes might well also do the trick.

    Cheers

    The Beryl Bloke
    Equipment er.... Projects I own

    Lathes - Sherline 4410 CNC
    Mills - Deckel FP2LB, Hardinge TM-UM, Sherline 2000 CNC.

  6. #6
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Chris, Guys,

    That carbide drill looks to be very good value ! It would be at least double that price here from MSC.
    Best Regards:
    Baron J.

  7. #7
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    9,088

    Default

    Quote Originally Posted by jack620 View Post
    5mm is the tapping drill for a M6 tap. The price is right.
    You aren't holding the wing on a plane. I'd be trying something much bigger say 5.5mm?
    I have a % thread fepth chart some where but can't lay my hands on it atm.

  8. #8
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    An aeroplane is my next project. I have a thread engagement chart too. I’ll have a look. I hate the feel of sloppy threads though. They don’t scream “quality” to me. The treaded part will only be about 10mm deep so I can always open that up a bit with my small boring bar. Good point though.
    Chris

  9. #9
    Join Date
    Jul 2016
    Location
    Melbourne
    Age
    35
    Posts
    1,522

    Default

    I second the suggestion of a lower percentage of thread engagement. The feeling of slackness doesn't really come so much from the engagement but the thread form anyway. 60% you just won't notice, except you'll be able to see the threads clearly because there won't be a snapped tap jammed in the hole.

  10. #10
    Join Date
    May 2010
    Location
    Perth
    Posts
    135

    Default

    I won't comment on the threading, but will give some hard earned pointers on machining titanium on a taig lathe.

    keep your tool tip clean and sharp - with a boring bar or turning tool I would take two passes, then use a small slip stone to take the galling Ti off the HSS tip, then 2 more passes, swipe, etc - I got lazy and complacent once and on the 4th pass there was a small puff of white smoke, and the tip of the HSS cutter had melted away.

    when I was drilling, I used trefolex as lube, and peck drilled. in my case it was 1/4" holes through 20mm thick slices of Ti (from bolts) which I then bored out to ring sizes.

    all of my tools (cutters, drills, etc) were HSS, and as long as the buildup on the cutting face was removed, they worked fine, and did not blunten

    Des

  11. #11
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default

    In another life in aircraft structural maintenance I drilled and reamed quite a lot of titanium - both fasteners and structural components/fittings. We generally used 120deg split point HSS cobalt drills in hand held pneumatic drills, and the reamers were just straight flute HSS machine reamers. Never had to drill any really deep ones, but often around 5x diameter to take splined screw extractors
    As others have said the key is to keep the tool cutting, and with the air drills if you eased off the feed pressure too much and let the RPM get out of control they would spin, work harden, and burn the edges off the drill bit or reamer.
    We used either Trefolex or Rocol as a cutting compound. If the tool starts to get dull sharpen or change it.

    Steve

  12. #12
    Join Date
    Dec 2007
    Location
    Melbourne
    Posts
    1,628

    Default

    I know it has been suggested to use trefolex which in my experience is a paste. So this may not be required. If you wanted to do a drip or flood coolant you can always set up a temporary diy drip feed coolant with a upside down hanging 2lt soft drink bottle with a hole drilled in the cap and a hose attached. Poke a hole in the base (which will be the top when inverted) and enlarge until you get the desired flow rate.
    …..Live a Quiet Life & Work with your Hands

  13. #13
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    1,656

    Default

    Trefolex is also available as thick fluid

  14. #14
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Guys,

    The tin of Trefolex that I have is a bit like thick grease ! But it takes very little heat to melt it into a thin oily liquid.
    If I remember correctly, it is basically a mixture of lard and sulphur with some other stuff mixed in.
    It is amazingly effective on taps and when drilling holes, particularly deep ones. I also use it on my hacksaw blades, that is when you most notice the reduction in effort.

    My tin must be well over twenty years old by now, and if I spotted a new tin for sale I would buy it tomorrow.
    I've got a can of Rocol RTD, I'm not keen about it, it also stains, which I don't like.
    Best Regards:
    Baron J.

  15. #15
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    Thanks for the replies all. I have Trefolex in paste, liquid and spray can forms.

    Des’s post has got me thinking that Crobalt might work well on Ti. My diamond tool holder with a crobalt cutting tool cuts SS like butter.
    Chris

Page 1 of 2 12 LastLast

Similar Threads

  1. Finishing titanium?
    By jhovel in forum METALWORK GENERAL
    Replies: 27
    Last Post: 23rd Nov 2020, 10:18 PM
  2. Titanium spectacles repair
    By russ57 in forum JEWELLERY
    Replies: 3
    Last Post: 3rd Nov 2017, 10:15 PM
  3. Pin chuck ?? for closed end pens
    By arose62 in forum METALWORK GENERAL
    Replies: 2
    Last Post: 8th Oct 2009, 09:42 AM
  4. Milling Titanium
    By glock40sw in forum METALWORK GENERAL
    Replies: 1
    Last Post: 30th Aug 2007, 07:42 PM
  5. Titanium
    By Chris Parks in forum METALWORK GENERAL
    Replies: 8
    Last Post: 7th Jan 2007, 10:39 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •