How Have Your Metal On Plastic Threaded Pens Fared Over The Years?

[DevrimJan]

Title pretty self explanatory. I have heard that threads made of differing materials tend to have the softer threads wear out over time. I know that many pen companies do this with pretty much their entire line (such as Sailor with there metal section threads screwing into their resin/ebonite barrels). Others do it with particular models (like Visconti & OMAS with certain metal sectioned pens that screw into resin caps). Does this cause the softer material to wear out over time? Is this a poor design choice?

[jar]

I have not found it to be an issue when it is well made pens originally.

[DevrimJan]

Shameless bump.

[Michigan]

Can you give us examples of metal on plastic threaded pens? I have four metal cap pens, but none has that situation.

 

My metal MB 146 has plastic on plastic threads. It is still going strong after 17 years.

 

My OMAS Marconi in sterling has a bit of wonkiness with the threads. I can screw it past the point of tightness and it becomes loose again. It is plastic on plastic. Frankly, OMAS makes great writers, but it is not built to the standard of my MB.

 

My metal Montegrappa screws on, but metal does not touch manmade material in doing so. Works well.

Edited March 16, 2016 by Michigan

[Jackokun]

  On 3/3/2016 at 1:42 PM, jar said:

I have not found it to be an issue when it is well made pens originally.

Same here

[jar]

  On 3/16/2016 at 5:00 AM, Michigan said:

Can you give us examples of metal on plastic threaded pens? I have four metal cap pens, but none has that situation.

 

One that I am using today is the Platinum Izumo line. The threads inside the cap are simply cut into ebonite.

 

http://www.fototime.com/6D19BEBE106F275/large.jpg

[tinta]

Initially I had similar concerns about the metal to plastic threads on my Sailor 1911 Standards. I thought that the female threads cut into the resin barrels might wear out prematurely, when mated with the metal male threads of the sections.

I only have few pens in my collection, so the Sailors get a lot of action. After more five years of continuous use, the softer female threads are holding up just fine.

 

** When joining any threaded parts on a pen, it's important to line up the parts carefully before screwing them together. Proceed slowly until the threads fully engage & never over tighten.

[fountainbel]

Hi ,

Threading wear is far more risky when both the male and female threads are in the same material .

A rule of thumb I've learned and remember im my early engineering classes says :

"Avoid mating female and male threads having the same hardness, avoiding galling and fretting problems over time "

During my repair experiences I was too often confronted with worn cap/barrel threads made in the same material .

This is in fact the reason why I've opted for the male titanium thread clutch on my Bulkfiller design.

So using a harder material for the male thread is the optimum choice in my opinion.

However if one screws the cap always on applying an exaggerated torque , the softer material will logically start wearing first.

But doing this with the plastic/plastic thread combination the male and female threads would start galling and fretting in each other and fail at a much earlier stage.

Just my 2 euro cents…..

Francis

[Russ]

A little silicone on the metal threads helps resist corrosion and smooths turning ... just don't overtighten.

[Ron Z]

It depends on the pen. Some do just fine. Others like the Namiki VP pens have problems with the plastic threads wearing and stripping. Maybe because of corners of the slot catching the plastic. I replace these with brass threads, avoiding the similar metals problem. Some have been out there, with no problems to my knowledge, for about 8 years.

[ParkerDuofold]

Hi all,

 

One thing I do to help counter this concern is whenever I'm dealing with threaded components... I counter-rotate the cap/section and barrel until they "drop into place." Then I tighten using the proper rotation direction.

 

By permitting the threads to lock together during the counter-rotation makes for much smoother tightening and less wear to the threads.

 

This is a good technique whenever you're dealing with threaded components.

 

Be well and enjoy life.

 

 

- Anthony

[senzen]

People have similar concerns with camera lenses, with their plasic threads and metal filters; no problems whatsoever, and I use filters quite a bit.

[Bookman]

My oldest pen that fits the category is my Waterman Exclusive (metal barrel and threads, plastic section and threads), which has been in regular use for 13 years. I haven't had a problem so far with joining the barrel to the section, even after a couple three four glasses of champagne. I never thought there was any reason to be concerned. Now I'm feeling a bit anxious. It's in my head now.

Edited August 13, 2017 by Bookman