# Screw-on cap threads



## LarryJB (Aug 4, 2016)

I am sort of new to turning pens and have been trying to learn the dos and don'ts of the sport.  Anyway, I have tried my hand at several different kits and I have made a few that have screw on caps.  I have been carrying around various examples of these pens to see what I like about them and what I don't.  Especially their durability.  It seems to me that the ones with the screw on caps all seem to have the same problem.  The threads in the cap all seem to be made of plastic and after only a few months of use the threads will strip out.  A couple of months of basic use seems pretty short before it wears out.  I would expect a nice pen to last several years before anything wears out on it.  Granted, I have not made a $30 kit as of yet, but I would expect a pen made from a $10 kit that some say will sell for $80 or more should last more than a couple of months.
Ok, rant over.  Am I just not making the right kit, or is there something I can do to make the threads last longer?


----------



## magpens (Aug 4, 2016)

Back to you ... please specify the kits you used for the pens you are carrying around.

Thanks.


----------



## Skeels (Aug 5, 2016)

Haven't made many pens with a screw on cap but I think u may have answered your own question.. Or maybe not. Personally, I wouldn't buy a pen with plastic threads. I carry my pen in my pants pocket all day so it sees some movement, and as a welder I tend to be kneeling quite a but, even rollin around on the floor lol. Now I wouldn't be bringin that kids pen to work anyway but with how I abide my pens, plastics threads would be a no no for me. If it's not the plastic, maybe it's you over torquing when reinstalling they cap. I could see myslef doin that some I'd want to make sure I had a good thread lock, an on that note they would probably only last me a week lol.
If your plan is to sell them, I'd buy one... Maybe two of a better kit and see what happens. I'm a firm believer in gettin what you pay for. I can't remember where exactly I read it but I remember a statement sayin they'd rather buy pen kit B for 5 bucks than pen kit A for a buck and a half. He said even though they both sold for "x" amount and he didn't make as much profit, in the end he sold a better pen. That's what I started doin. I got into the hobby to make some side cash. I don't make as much sellin my pens now than I did when I first started cause I'm payin more for the kits, BUT I feel the end result is a better pen in the long tun... Which makes me feel a little better about selling them.just my two sence though.


----------



## LarryJB (Aug 5, 2016)

magpens said:


> Back to you ... please specify the kits you used for the pens you are carrying around.
> 
> Thanks.



Well, let's see, I believe I have used the PSI Classic, Tycoon, and also the Woodturningz Orion.  All have plastic threads in the cap and metal threads on the pen body.  Can someone recommend a kit that does not have plastic threads in the cap?


----------



## beck3906 (Aug 5, 2016)

One reason for using plastic threads is for the caps to stay tightened when in place.  Metal to metal threads seem to work loose even in your shirt pocket.


----------



## RobS (Aug 5, 2016)

I just ordered the following kits that are supposed to be made of all Stainless Steel.  https://pengeapens.myshopify.com/co...cts/raven-roller-ball-pen?variant=15396197446

They are just under $30 each, not cheap but will not break the bank.
I had my plastic threads break on my everyday carry pen my neighbor made me, so I plan on upgrading to the kit above.  Please not I have not made it yet so I can not vouch for it.  I can just tell you they are made here in America and uses all Stainless steel parts.

Cheers


----------



## LarryJB (Aug 5, 2016)

beck3906 said:


> One reason for using plastic threads is for the caps to stay tightened when in place.  Metal to metal threads seem to work loose even in your shirt pocket.



I thought it might be something like that.  The durability sure does suffer though.  I have tried to be more careful with the one I am carrying now (Orion), and the threads have held up better.  I have also learned that when I let someone use my pen for a moment, I always remove the cap before handing it them, they are sometime confused as to how to remove the cap, most people pull on it, and then when they put the cap back on, they tighten ti too much, all of which will strip out those plastic threads.  Now, even with me being careful, the thread sleeve (or whatever it is called) has broken loose from inside the cap and slides up and down.  I think a carefully placed drop of CA glue should fix it.


----------



## LarryJB (Aug 5, 2016)

RobS said:


> I just ordered the following kits that are supposed to be made of all Stainless Steel.  https://pengeapens.myshopify.com/co...cts/raven-roller-ball-pen?variant=15396197446
> 
> They are just under $30 each, not cheap but will not break the bank.
> I had my plastic threads break on my everyday carry pen my neighbor made me, so I plan on upgrading to the kit above.  Please not I have not made it yet so I can not vouch for it.  I can just tell you they are made here in America and uses all Stainless steel parts.
> ...



Have you actually seen this kit?  It looks to me like the female threads in the cap assembly may be plastic as well.  Hard to tell from the picture though. Plus, I prefer gold tone.


----------



## RobS (Aug 5, 2016)

LarryJB said:


> RobS said:
> 
> 
> > I just ordered the following kits that are supposed to be made of all Stainless Steel.  https://pengeapens.myshopify.com/co...cts/raven-roller-ball-pen?variant=15396197446
> ...



I'll let you know as soon as they come in, they just shipped out today, so likely will not make it here till next Friday, Georgia to California.
RobS


----------



## mecompco (Aug 5, 2016)

LarryJB said:


> beck3906 said:
> 
> 
> > One reason for using plastic threads is for the caps to stay tightened when in place.  Metal to metal threads seem to work loose even in your shirt pocket.
> ...



Yes, the majority of people will attempt to pull the cap off. I have taken to using blue Loc-Tite when assembling all of my pens. On a fountain pen/rollerball, I always put a dab on the plastic thread insert as well as the other pressed in parts. Just a suggestion. Oh, and with the Loc-Tite, one can still disassembly the pen if needed.

Regards,
Michael


----------



## LarryJB (Aug 5, 2016)

So, if most of these are plastic, I wonder if that thread sleeve could be replaced?  Can you buy just the thread sleeve?


----------



## mecompco (Aug 5, 2016)

LarryJB said:


> So, if most of these are plastic, I wonder if that thread sleeve could be replaced?  Can you buy just the thread sleeve?



I know you can for the Jr. Gent and Atrax, which is what I mostly make. It is rather a challenge getting them out, I've found, but it can be done.

Regards,
Michael


----------



## glenspens (Aug 5, 2016)

I have had good luck with all of Lazerlinez kits well made kits.


----------



## LarryJB (Aug 5, 2016)

glenspens said:


> I have had good luck with all of Lazerlinez kits well made kits.



I am sure they are, but is the threaded insert in the cap plastic?


----------



## southernclay (Aug 5, 2016)

LarryJB said:


> glenspens said:
> 
> 
> > I have had good luck with all of Lazerlinez kits well made kits.
> ...


 
Larry in all of the capped pens sold on the site now they are, they used to be metal on metal but there is now a threaded delrin (I believe) insert.


----------



## LarryJB (Aug 5, 2016)

southernclay said:


> Larry in all of the capped pens sold on the site now they are, they used to be metal on metal but there is now a threaded delrin (I believe) insert.



Sorry for my ignorance, but what exactly is delrin?


----------



## RobS (Aug 5, 2016)

Delrin (Acetal) is a relatively strong plastic, used by most engineers for fixtures and tooling.  

quick cheat sheet: McMaster-Carr

more detail (Acetal)
McMaster-Carr


----------



## bmachin (Aug 5, 2016)

I think this has been discussed recently, although I can't find the thread.

I seems to me that, unless the kit manufacturer did a poor job of choosing materials or made the parts out of spec, over-torqueing is the leading candidate for your problem.

Many (maybe most) high end pen manufacturers use plastic on plastic threads for their caps; for example:  Montblanc, Pelican, Edison, Bexley, and Parker (on the Duofold). 

The several Alumilite and Ebonite pens that I have made, show no signs of wearing out.
I have, as well, an 80 year old Parker vacumatic which still closes fine, although things are getting a little loose and I have to be careful.  My wife has a 100 year old Todd eyedropper that is exceedingly smooth and tight although it is probably ebonite.

Fear not the polymers!

My opinion only, your milage may vary.

Bill


----------



## Curly (Aug 5, 2016)

The reason the component parts have plastic to metal threads is to prevent damage of the threads you get with metal to metal threads. On kits where they are plated the plating scrapes off making for a rough thread and the base metal showing through. On the stainless metal to metal threads they can gall and get rough. The only way you can have metal to metal threads at this time is to get into custom pen making (kitless) where you can pick and choose the materials in your pen and control the fit and finish. Quite a leap if you are only playing with a few pens now and then.


----------



## LarryJB (Aug 5, 2016)

Curly said:


> The reason the component parts have plastic to metal threads is to prevent damage of the threads you get with metal to metal threads. On kits where they are plated the plating scrapes off making for a rough thread and the base metal showing through. On the stainless metal to metal threads they can gall and get rough. The only way you can have metal to metal threads at this time is to get into custom pen making (kitless) where you can pick and choose the materials in your pen and control the fit and finish. Quite a leap if you are only playing with a few pens now and then.



I don't know then, maybe I am just incredibly tough on these pens, but every single one that I have used on a regular basis, the cap will just fall off due to the plastic threads being stripped out.  Maybe I need to try one with a magnetic cap.  How do those work?


----------



## jttheclockman (Aug 5, 2016)

Larry yes this topic has been discussed before and one of the big reason is metal on metal as mention has down side for tear out and also becoming loose in one's pocket. You can do a search here and find several threads on this. 

The one thing I will say is to me and this is just my opinion. A screw capped pen is more of a luxurious pen. It is not designed to be abused. Mostly used as desk pens. When someone has one they should realize they are handling a higher end type pen. If you use pens on a regular basis why not switch to something like a cigar pen or so many other that are just twist tops. But with your force you may still find these to not be sturdy enough. Maybe switch to pencils

You ask about the magnetic caps. Again like all other pens on the market weather famous brand or cheap brand or somewhere in between has pros and cons. I started out not liking the Zen pen because I felt the magnetic cap would have a tendency to fall off. I have warmed to these pens and now include them in my line. But I will tell you the cap can come off depending on factors of your shirt. Too tight a pocket and the cap pulls off and the pen stays in the pocket. Been there done that. When selling pens you need to educate the buyer the best you can and then it is their problem. As for yourself you should be able to learn from working with pens what will work or not. I basically can not anything more than what was said. Good luck and lighten up on the grip


----------



## LarryJB (Aug 8, 2016)

Thanks for everyone's input.  Like I said earlier, I am pretty new to this whole idea of turning pens and still have so much to learn.  This is just one of many things I have yet to learn about.  At this point I am not even considering making pens to sell, but I may in the future after I retire, but a whole lot of cards will have to fall just right before that happens.  But if it does, all this info will come in quite handy.

Thanks again!


----------



## Phil Dart (Aug 8, 2016)

The principle reason that kit manufacturers make their insert threads from plastic, as Pete has already touched on, it to stop metal on metal wearing the plating off. With respect, I have to say that if you are consistently having a problem with threads stripping out across several different kits, it is possible that you are being a little heavy handed with them.

It's true that many of the cheaper Chinese kits have poor quality threads inside the cap, but in the main, most of the mainstream manufacturers who source their pens from Taiwan, PSI is one you mentioned, have pretty good standards.

Where they do fall down is by having a so called metric thread, which is to say that the cross section of the thread itself is triangular. A much stronger solution is to have Acme type threads or square threads which are altogether much more robust. There are only a tiny handful of manufactures worldwide who make their kits with those types of thread, my company is one of them, and Dayacom is another.(although even though it is in the interest of public information, this post will probably be deleted for saying so, as it will undoubtedly be deemed to be contravening the sites advertising rules)

So if you want to be sure that the cap thread is as robust as possible, look for kits that have acme type threads instead of metric threads. You will find though that they tend to be the more expensive kits.


----------



## corgicoupe (Aug 10, 2016)

Woodcraft used to carry an earlier version of the Lazerlines pens that had stainless steel threads in the cap, but there were complaints about galling, and Constant switched to the delrin. I bought a new old stock fountain pen at my local Woodcraft store, and was able to minimize the problem with silicone grease. Since they no longer carry them, you may be able to get a discount if they still have a couple on the shelf. The kit was called Hancock, and uses Jr Gents II bushings and drills.


----------



## eharri446 (Aug 11, 2016)

The Woodcraft store on Holdcomb Bridge Rd in Atlanta had a couple of the Hancock kits a few weeks ago. I do not know if they still have them though.

You could give them a call and see if they still have them and if they do you could have them hold them for you.


----------



## corgicoupe (Aug 13, 2016)

I was there today and there are 2 RB kits still availabe, and they have 1 set of the bushings. Robert, the manager, said he would take $20 for each kit, and $5 for the bushings. Original price WA $30 & $8, respectively, so it's a good price.

If they had been FPs, I would have bought them.


----------

