Advice on knurling titanium

Thank you for the reference Petertha. It looks like there is some very useful information there.

I have attached some photos to further clarify what I have done so far on this project and the purpose of the knurled rod. One picture is of the short aluminum receptacle available on-line and the other is of the long custom receptacle made of it titanium.

If I am unable to knurl the titanium I suppose I could mill some grooves on the rod but would prefer to knurl if possible.

Still no word from Dorian.FD4C8C44-D662-4AF3-9C79-733B27E8E258.jpeg358F5781-B722-4963-B883-A084A3260AFD.jpegA4910626-6405-4E45-91A3-1171B7A74E46.jpeg3AC08B66-A989-4E81-917D-651BBD20D99C.jpeg730A3302-2A5C-45A4-8B77-CABF1E1DE699.jpeg
 
Good luck with Dorian - IMO some of the worst of the worst in terms of customer service and technical advice.

Call Eagle Rock Technologies and talk to them. They'll give you some help based on my experience. They sell some very nice knurlers.

Welcome to the board!
 
Alan, thanks for the link to Eagle Rock Technologies. I looked at their website but did not see any three wheel knurling tools. I believe I need this style end-feed knurling tool for my job since the stock has a relatively small diameter and there would be a considerable amount of side pressure with in-feeding.

So far your opinion regarding Dorian seems to be accurate. Seems like a pretty simple question for them to answer: will the tool I am ready to purchase do the job I that I intend to use it for?

Thanks for the “welcome” and the advice!
 
I used to run some 316 ss parts that had a straight knurl on OD. They were 1.5 dia and I would send them out to a company that did thread rolling. I ran them a thousand at a time. Many machinists don’t know that knurls can be rolled. Of all the parts made I never had a bad knurl.
 
I have an eagle rock two wheel pinch knurler , no side pressure, ied give it a try
 
I think your local machine shop may also be partly put off by the idea of form knurling a length of bar then cutting it into lengths and conducting turning operations on the ends, as with this plan you are first degrading your reference and holding surface, then expecting them to hold it to work on the cut ends, I'd be inclined to turn you away politely if you presented this plan to me as part of an RFQ.
For a job like this the raw material should be suitable for turning, the machine shop will want to load a length of stock, face, turn and cut off a part, advance the stock and repeat for the full batch, then carry out any work on the cut end.
Regards,
Nick
 
Jim, I have contacted several companies regarding cold forming splines on the rod. If they will work with a small run(maybe ten, one foot rods) I think this would be my best option.

Thanks again for everyone’s input,
Mike
 
I think your local machine shop may also be partly put off by the idea of form knurling a length of bar then cutting it into lengths and conducting turning operations on the ends, as with this plan you are first degrading your reference and holding surface, then expecting them to hold it to work on the cut ends, I'd be inclined to turn you away politely if you presented this plan to me as part of an RFQ.
For a job like this the raw material should be suitable for turning, the machine shop will want to load a length of stock, face, turn and cut off a part, advance the stock and repeat for the full batch, then carry out any work on the cut end.
Regards,
Nick
I make a recurring 304 SS part, 1/2" dia. X 4 .75 long fully knurled OD with a .265 hole thru and a .315 +.001 -.000 X .472" deep bore in each end. I knurl from a long bar then cut, hold them in steel soft jaws to face, drill and bore and it works fine, the knurl anchors an expanded urethane coating applied afterwards. If the knurl on the OP's part is merely ornamental this approach would work fine, the softness of titanium may require aluminum soft jaws however, 6al-4v annealed is 36 Rc.

As far as knurling 36" lengths that is a tough one. An infeed thread roller would form the knurl but would not feed itself I suspect.
 
I make a recurring 304 SS part, 1/2" dia. X 4 .75 long fully knurled OD with a .265 hole thru and a .315 +.001 -.000 X .472" deep bore in each end. I knurl from a long bar then cut, hold them in steel soft jaws to face, drill and bore and it works fine, the knurl anchors an expanded urethane coating applied afterwards. If the knurl on the OP's part is merely ornamental this approach would work fine, the softness of titanium may require aluminum soft jaws however, 6al-4v annealed is 36 Rc.

As far as knurling 36" lengths that is a tough one. An infeed thread roller would form the knurl but would not feed itself I suspect.

is your knurl creating an equivalent material deformation/displacement to 12 TPI knurl on 5/16 rod with well in excess of 40 though diameter increase though? ;-)
 
What I want to do is not precision work so the form of the teeth is not important. The piece is used in fishing pole construction. It is the center of a handle extension that cork rings are slid onto and glued and then formed on a lathe. The teeth just dig into the cork and keep it from rotating. I will attach some photos to help clarify. Unfortunately one as long as I want is not produced.

Been thinking about this and a cut knurler is the most expensive way I can think of to do this. Not even sure if knurling is even necessary. I would think that you could coarse sand the Ti bar and the inside of the cork rings and rely on the epoxy to bond the two solidly. On the other hand, if you decide a knurl is necessary then a simple scissors knurler, like the Eagle Rock the guys pointed to, should work fine. You are not doing any axial running; just making a knurl in multiple places, so convex knurls or radius edged knurls are not needed.

If you ordered an Eagle Rock knurler with carbide pins and cobalt knurls, it would work. You need to experiment with the torque required to get a 90% depth pattern, ideally using a torque wrench so you can duplicate the torque for each knurl. Then you can move the knurler to the spot you want to knurl, torque it down to get the pattern you need, knurl it and move to the next spot.

If you need to turn down and screw cut the end, I would do that first. Then unclamp the work and move it out as needed to make each knurl. You would still need to support the end with a live center but doing it this way would be pretty fast.

If you're going to go into production and sell these titanium extensions then the cost to do this might be justifiable but for a one-off ... not so sure.
 
Back
Top