# Advice on knurling titanium



## Titanium Knurler (Jan 18, 2018)

Hello All, first post here.  I have some questions on straight knurling a 5/16”, Grade 5 titanium rod.  I would like to knurl a 24”-36” rod creating 12 teeth along it’s length.  The toothed rod will then be cut into shorter 11” pieces and two inches of the end turned down and threaded to 1/4-20. My questions are mostly related to whether it is possible to form knurl titanium.  The local machine shop that would be doing the work does not think it is possible to knurl titanium.  I have done some research and this is what I would like him to try:

Dorian Heavy Duty, three wheel knurling tool(3WKT-40-M,UPC23033)
Cobalt,12TPI, beveled knurling wheels(MS-12-CB,p/n 25339)

My calculations using the information on the Dorian website indicate that this set-up would form(not cut) 11.2 teeth(fine for my application and hopefully close enough that I won’t have any double tracking) and would give me a tooth elevation of .031 inches(also fine for what I m doing.

Does anyone have any experience with knurling titanium? Does anyone have experience with the Dorian three wheel knurling tool? Is what I propose possible with titanium or should I give up on this project as the machine shop suggests?

Thanks for your help!

I will try to post a link to Dorians website(doriantool.com) if it is possible to post links on this forum, so that you can see the three wheel knurling tool that I am considering. The website also has a nice little video of the the three wheel knurler in action on a long thin rod. Looks great to me, but will it knurl Grade 5 titanium?

I will also try to attach a photo of piece similar to what I want to make out of titanium, it’s just about half the length of what I want to make.


----------



## Boswell (Jan 18, 2018)

Have you talked to the Dorian tool company about this to get their thoughts?


----------



## Titanium Knurler (Jan 18, 2018)

I have sent a couple of emails and phoned a couple of times and left some voicemail but no response yet but apparently they have been having some “severe” weather there(freezing rain).  I live in Wisconsin so hard to get too excited about freezing rain but I understand they are unprepared for such weather in Texas.  Will keep trying.

Thanks for your help,
Mike


----------



## chips&more (Jan 18, 2018)

First welcome! You want to move titanium so that you have 12 teeth with a 0.031” pointed rise on a 5/16 diameter? Have you ever worked with titanium before? It’s fun stuff! First off, I can’t see the formed point of the rise being of any good quality and or straight. Maybe machine the thing instead of forming with knurls. Or buy it extruded if possible. Or EDM it. My 3 cents...Dave


----------



## Nogoingback (Jan 18, 2018)

I have no experience with this, but there are several posts on that subject on the forum.  Here's one that might help:

https://www.hobby-machinist.com/threads/knurling-titanium.16134/#post-181630


----------



## brino (Jan 18, 2018)

I have not done it myself, however there were some amazing examples shared by Will (@darzero) in a thread here.
Unfortunatley, when PhotoBucket changed to a paid service those links were severed and we lost the pictures.
That thread is here (minus the pictures):
https://www.hobby-machinist.com/threads/knurling-advice.57273/post-471199

I wonder if Will still has some photos he could/would repost on this site?!?

-brino

EDIT:
Some of Will's photo's are actually in the thread pointed to above, here are some direct links:
https://www.hobby-machinist.com/threads/knurling-titanium.16134/post-166609
https://www.hobby-machinist.com/threads/knurling-titanium.16134/post-167767


----------



## mikey (Jan 18, 2018)

Yup, @darkzero  is the man when it comes to knurling Titanium. He does beautiful work.


----------



## Titanium Knurler (Jan 18, 2018)

Wow, thanks for all of your feedback!

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.  
	

		
			
		

		
	



	

		
			
		

		
	
A
	

		
			
		

		
	













	

		
			
		

		
	
Sorry, just had to throw the fish picture in!


----------



## Titanium Knurler (Jan 18, 2018)

Sorry about all the pictures, Forum gave me the choice of thumbnails or full size image; looks like it/I sent both.

Just had to send fish picture but it illustrates why I am using titanium instead of aluminum since there is a lot of stress put on this part with a large salmon on a fly rod.


----------



## petertha (Jan 18, 2018)

Cant speak to titanium, but I built a spreadsheet using the simple equations on this website. It dramatically improved my knurling quality once I pre-determined the correct starting diameter within tolerance relative to the chosen knurl wheel parameters. They might be another good contact reference as its their core business. At least I found them very helpful on the phone.
http://accu-trak.com/technicalinfo.html


----------



## Titanium Knurler (Jan 18, 2018)

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.


----------



## Alan H. (Jan 18, 2018)

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!


----------



## Titanium Knurler (Jan 18, 2018)

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!


----------



## Jimsehr (Jan 18, 2018)

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.


----------



## dlane (Jan 19, 2018)

I have an eagle rock two wheel pinch knurler , no side pressure, ied give it a try


----------



## magicniner (Jan 19, 2018)

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


----------



## Titanium Knurler (Jan 19, 2018)

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


----------



## Wreck™Wreck (Jan 19, 2018)

magicniner said:


> 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.


----------



## magicniner (Jan 19, 2018)

Wreck™Wreck said:


> 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? ;-)


----------



## mikey (Jan 19, 2018)

Titanium Knurler said:


> 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.


----------



## Jimsehr (Jan 19, 2018)

Titanium Knurler said:


> Hello All, first post here.  I have some questions on straight knurling a 5/16”, Grade 5 titanium rod.  I would like to knurl a 24”-36” rod creating 12 teeth along it’s length.  The toothed rod will then be cut into shorter 11” pieces and two inches of the end turned down and threaded to 1/4-20. My questions are mostly related to whether it is possible to form knurl titanium.  The local machine shop that would be doing the work does not think it is possible to knurl titanium.  I have done some research and this is what I would like him to try:
> 
> Dorian Heavy Duty, three wheel knurling tool(3WKT-40-M,UPC23033)
> Cobalt,12TPI, beveled knurling wheels(MS-12-CB,p/n 25339)
> ...





Titanium Knurler said:


> Hello All, first post here.  I have some questions on straight knurling a 5/16”, Grade 5 titanium rod.  I would like to knurl a 24”-36” rod creating 12 teeth along it’s length.  The toothed rod will then be cut into shorter 11” pieces and two inches of the end turned down and threaded to 1/4-20. My questions are mostly related to whether it is possible to form knurl titanium.  The local machine shop that would be doing the work does not think it is possible to knurl titanium.  I have done some research and this is what I would like him to try:
> 
> Dorian Heavy Duty, three wheel knurling tool(3WKT-40-M,UPC23033)
> Cobalt,12TPI, beveled knurling wheels(MS-12-CB,p/n 25339)
> ...


I found a company that sells knurled bar stock in 12 ft of shorter lengths. 
Their name is RA - White phone 800 556-4452 
If I read it right they have a 316 ss  bar 1 inch dia 12 ft long 35 # for $160 shipped.    
They say Allmost any    metal can be knurled.


----------



## Titanium Knurler (Jan 19, 2018)

Wreck, thanks for your input. I am genuinely surprised at the help I have received.  I am also surprised at how difficult this project seems to accomplish. 

I did finally get a response from Dorian.  He feels it can be accomplished with the three roller knurling tool but recommends 20 TPI instead of the 12 TPI I had planned due to the small diameter of the stock and it would be less likely to double track.

I will keep you posted.


----------



## Wreck™Wreck (Jan 19, 2018)

magicniner said:


> 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? ;-)



I haven't the faintest clue what this means (-:

I will not buy this record it is scratched.


----------



## Titanium Knurler (Jan 19, 2018)

Mikey, all really good points! You ever have a project that you thought would be simple and before you know it your thinking about buying a thousand dollars worth of tools for a one-off!  Well, I am there.  I need to reel myself in a bit.  Your idea of just roughing up the surface and gluing the damn thing is a reasonable approach and will most likely do it but first I have to check out the great lead from Jimsehr about RA White. An old company that says that can knurl just about anything-thanks Jimsehr. Unfortunately I will have to wait until Monday. Thanks again everyone for your help!


----------



## Wreck™Wreck (Jan 19, 2018)

Titanium Knurler said:


> Wreck, thanks for your input. I am genuinely surprised at the help I have received.  I am also surprised at how difficult this project seems to accomplish.


I have never seen a Dorian 3 roll knurl tool, is it a box tool?


----------



## Bob Korves (Jan 19, 2018)

I must admit that I don't think I have ever held titanium in my hand...


----------



## Titanium Knurler (Jan 19, 2018)

Wreck, tried to cut and paste a photo of it but was unable.  If you go to www.doriantool.com and go to pg. H55 of their knurling catalogue you will see photos of it.  The website also has a link to a brief YouTube of it in action. Great idea for small diameter stuff.
Bob, my first time working with titanium-needed the strength, lightness and corrosion resistance.  Very important project-there are fish to be caught!


----------



## mikey (Jan 19, 2018)

[QUOTE="Titanium Knurler, post: 548072, member: 49201"You ever have a project that you thought would be simple and before you know it your thinking about buying a thousand dollars worth of tools for a one-off!  [/QUOTE]

Every single one of us will be in this situation at some point, and I have been there before myself. 

I've built maybe 50 rods so far, from beach casters to small game to Ulua rods. I have used cord, Hypalon and cork and never thought I needed a knurled surface to hold grip material. Not saying you shouldn't but a properly roughed up and cleaned surface will bond cork tightly with the right epoxy. I use regular 2-part epoxy, not the 5 minute stuff and never had a grip come apart. Maybe give it some thought.


----------



## Titanium Knurler (Jan 19, 2018)

Thanks Mikey, I believe I am rapidly approaching that solution.  Will just follow-up on last lead on CA knurling company. If that falls through I will get out the sandpaper and glue. Hate to give up.


----------



## rwm (Jan 19, 2018)

Sandblast (microknurling) then epoxy!
R


----------



## Titanium Knurler (Jan 19, 2018)

I like it but I think I will call it “nano-knurling”-very trendy.


----------



## Wreck™Wreck (Jan 19, 2018)

Titanium Knurler said:


> Wreck, tried to cut and paste a photo of it but was unable.  If you go to www.doriantool.com and go to pg. H55 of their knurling catalogue you will see photos of it.  The website also has a link to a brief YouTube of it in action. Great idea for small diameter stuff.
> Bob, my first time working with titanium-needed the strength, lightness and corrosion resistance.  Very important project-there are fish to be caught!


As I suspected it is a box tool, the one with the round shank is hollow for use in turret lathes where the work passes through the tool. This should work yet I can see it putting a bit of a torsional load on such a small diameter at 24" in length, give it a shot what is the worst that could happen?

Now that I think about it we have one with 3 rolls mounted in a cage that is held in the tail stock ram, naturally it is limited to several inches in knurl length but doesn't require a center. I have never used it but the other lathe machinist likes it, anything longer then 3" he pawns off on me. I use a straddle tool but have never been called upon to knurl more then 10-12 diameters in length so no useful information for you.

From Dorian's catalog.


----------



## Titanium Knurler (Jan 22, 2018)

While I am waiting to hear from the specialty shops that knurl and create splines I am wondering if someone can give me some advice on selecting the best size square post to mount the Dorian three wheel knurling tool to the lathe if I have to go this route.  This is also a segway into getting some advice on purchasing my first metal lathe. The square tool mount comes in four shank sizes: 0.500, 0.625, 0.750 and 1.00. There are a couple of size options for each size of knurling tool; the bigger the knurling tool, the bigger the shank options.  I know the size depends on what the machine shop’s lathe will accept but I was hoping to get a shank size that I could use on a home machine.  Is there somewhat of a standard for home sized lathes and can the tool holder be easily changed to accept different sized tool shanks?  For example, if I purchased a machine that used 0.500 shanks could this be easily changed to accept a 0.625 or 0.750 shank tool? Thanks


----------



## mikey (Jan 22, 2018)

Call me dense, T, but I didn't realize you didn't have a lathe to work with. Most of the advice so far assumes you have a lathe to use the tools we've been discussing. 

You will have far more input on choosing a lathe if you started another thread and addressed that specific question instead of burying the query inside an unrelated thread like this. Not all the guys may see it here. To prep you for that thread, search this site for info on choosing a first lathe; there are tons of threads like that. Then decide the scope of work you intend to do on the lathe because that is the key determinant on the size of the lathe you will need. Make a list of all the things you need the lathe to do and the size of the work you think you'll have to handle. If you don't know this yet then you'll get answers like, "... buy the biggest lathe you can afford or fit". The more info you can provide, the better and more specific the answers will be.

As for which shank to buy for a knurling tool, you guessed it ... it depends on the lathe you have because larger lathes will have larger tool posts that can accommodate larger tool shanks. Of course, there are tool holders that can fit larger tools on smaller lathes but there are limits to this sort of thing. So, first things first; get a lathe before buying expensive tooling to fit it.

Have you considered using Vise Grips to deform the shank of your work piece to form a pseudo-knurl? I don't know if you can do it on Titanium but that material isn't all that hard and you don't need a precision knurl, right? What if you just cranked down on the vise grip and made marks at the intervals you need; would that work? You would only have one chance at the pattern because the material will work harden quickly but I wonder if it might suffice. Something to consider.


----------



## benmychree (Jan 22, 2018)

Bob Korves said:


> I must admit that I don't think I have ever held titanium in my hand...


Me too, and damned proud of it!


----------



## Titanium Knurler (Jan 22, 2018)

Thanks Mikey.  I will look at the threads on choosing a lathe. My mistake for inserting them here.  My shop is incomplete. I have many woodworking tools but few metal working tools( drill press, milling machine, vertical and horizontal band saws) but no metal lathe.  I have needed to rely on a local machine shop for lathe work.  This project has re-enforced the fact that I need a lathe.  It was amazing to me what having a milling machine has done for my ability get things done I imagine I will see a similar increase when I get a lathe.

I just returned from the machinist. His CNC machines use a 1” shank and are MUCH bigger than any lathe than I am considering for purchase so the Dorian tool could only be used on a lathe in a large shop so vice grips and sandpaper are looking better and better(and cheaper and cheaper).

Very much appreciate your input.


----------



## mikey (Jan 22, 2018)

T, being lathe-less is a serious condition and requires near-immediate attention. It has been known to shrink man-parts and lead to mental illness if not treated so do not take this condition lightly!  

One of our Mods, @darkzero, has done some gorgeous knurling in Titanium. You cannot see his pics anymore because they were on Photobucket (now dead to him) but he uses a PM1236 lathe and an Eagle Rock knurler to produce beautiful work. I don't know what your needs are but have a look at the line of Precision Matthews lathes. I am not lathe-less like you but if I was, PM is where I would look first. 

Do let us know what you decide to do with your project. I would personally find some cheap way to roughen the Ti shaft and rely on a good epoxy to hold the cork rings. Cork is so friable that a knurl will not add much strength.


----------



## Titanium Knurler (Jan 22, 2018)

Mikey, I was concerned about my lathe-less state but your additional information has me really worried; I did not know man parts were involved.  I looked at the PM lathe website. They look very nice and priced in my range. I really like the large spindle bore.

Well big thanks to Jimsehr!  I followed up on your lead and talked to Carl at RA White.  What a great guy and he is a fisherman so he gets the crazy idea of mine. I will be sending him two 6’ pieces of 5/16” titanium rod for him to knurl at a reasonable price!  I will then have the machinist turn down and thread the knurled rod- I am back on track!

You know sometimes things happen that restore your faith in mankind and all the nice, constructive, and humorous posts on this site and have done that.  So, thanks everyone for your help!  I will update you all with photos of the project and hopefully a new lathe(before it is too late for my “man-parts”).


----------



## mikey (Jan 22, 2018)

PM has some really nice lathes but I would encourage you to define your work envelope and then ask the guys on the forum before choosing one; there is a lot of knowledge on this site about them. I did want to caution you that the smallest lathe they offer that comes with all the stuff a good lathe should have is the PM1127. 

Good luck, T!


----------



## Titanium Knurler (Jan 23, 2018)

Jimsehr said:


> I found a company that sells knurled bar stock in 12 ft of shorter lengths.
> Their name is RA - White phone 800 556-4452
> If I read it right they have a 316 ss  bar 1 inch dia 12 ft long 35 # for $160 shipped.
> They say Allmost any    metal can be knurled.



Jimsehr, thanks for the RA White lead. They will be knurling two 6’ lengths for me.


----------



## Jimsehr (Jan 23, 2018)

Titanium Knurler 
Would you post the cost and how well the knurls came out. I think that would help a lot of guys with their knurled parts. When you get the stock back from the knurling company. Maybe a  pic? When I was having a lot of knurling done it cost about the same to knurl a part as to thread roll a part. But I did about a thousand parts at a time.


----------



## Titanium Knurler (Jan 23, 2018)

Jimsehr,
Be happy to to post a picture and costs.
Thanks again for the lead.


----------



## magicniner (Jan 25, 2018)

Wreck™Wreck said:


> I haven't the faintest clue what this means (-;



Simple really, you were comparing Apples to Oranges, unless you're talking about a comparatively large knurl on a relatively small part in a material with similar characteristics then the comparison is irrelevant because the material deformation will not be comparable.
 ;-)


----------

