# Why are fountain pen reservoirs reverse threaded? **URL:** \ **Category:** Factual Questions\ **Created:** [February 5, 2020, 1:36am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515 "2020-02-05T01:36:58Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [February 5, 2020, 1:36am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/1 "2020-02-05T01:36:58Z")
I’ve got a couple of fountain pens–I like 'em. They’re classy. And after using them, reloading them, cleaning them, etc. over the course of five years, I’ve learned to write with them and not get ink all over my hands. That being said, of the four fountain pens I own, I use the refillable cartridge and bottles of ink. And it occurred to me today, “Righty tighty, lefty loosey–so why do I have to twist right to draw the plunger back and ink into the cartridge?” For Engineers, the threading does not follow the ‘right hand rule.’ Is there some historical reason for this? Everything else I own, right twists force a product out. Not on these four pens; there are three manufacturers involved, so I suspect this is an industry-wide thing. Tripler This sigline includes a flourish with good penmanship. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 5, 2020, 3:42am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/2 "2020-02-05T03:42:58Z")
> [@Tripler](#): > > Everything else I own, right twists force a product out. On everything you own, right twist _of the inner (male) screw_ forces it out. These fountain pen converts also have the standard thread screws. It’s just that the part you grab and rotate is the **female** (outer) screw; the plunger is connected to the male screw. Basically, you are turning the nut, not the bolt. So when you turn it clockwise, it pulls the plunger towards you. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [February 5, 2020, 9:33am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/3 "2020-02-05T09:33:22Z")
When I was young I had a beautiful fountain pen with iridescent stripes all over the body. That was a neat thing about fountain pens, they came in so many artful designs. The filler was different, and maybe some here have seen ones like this. It had a lever on the side that you pulled out to squeeze the rubber ink-filled balloon inside. Then when you put the lever back down, it sucked ink in. Pictures: (1) [In normal use](https://i.ebayimg.com/images/g/nWMAAOSwCwxdPI0H/s-l300.jpg): Note the silver-ish strip along the side that looks not-quite-like a pocket clip. It’s a lever that lays flat or slightly retracted in the side of the pen. (2) You [pull it out like this](http://www.fountainpennetwork.com/forum/uploads/monthly_05_2018/post-139272-0-74580000-1527123884.jpg) and then let it back down to fill the pen. No twisting anything. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [February 5, 2020, 9:42am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/4 "2020-02-05T09:42:22Z")
> [@scr4](#): > > On everything you own, right twist _of the inner (male) screw_ forces it out. Is this so? Does it depend on which end of the screw or bolt you’re looking at when you twist the screw or bolt (or nut)? I’m thinking of lug nuts on car tires. You twist the lug nut right (clockwise) to tighten it, if I remember right. (It’s been so long since I’ve had to change a flat. 🙂 ) In this case, you’re looking at the bolt from the “end” end, not from the “head” end. If you were able to look at the bolt from the other end, you’d be turning the lug nut counter-clockwise to tighten it. When I think of twisting a screw clockwise to turn it into the bolt, that seems the opposite at first thought – but then, I’m picturing looking at the screw from the _head_ end. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [February 5, 2020, 9:50am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/5 "2020-02-05T09:50:47Z")
Does a left twist remove the whole cartridge? ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [February 5, 2020, 9:53am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/6 "2020-02-05T09:53:06Z")
> [@Senegoid](#): > > Is this so? Does it depend on which end of the screw or bolt you’re looking at when you twist the screw or bolt (or nut)? > > I’m thinking of lug nuts on car tires. You twist the lug nut right (clockwise) to tighten it, if I remember right. (It’s been so long since I’ve had to change a flat. 🙂 ) In this case, you’re looking at the bolt from the “end” end, not from the “head” end. If you were able to look at the bolt from the other end, you’d be turning the lug nut counter-clockwise to tighten it. > > When I think of twisting a screw clockwise to turn it into the bolt, that seems the opposite at first thought – but then, I’m picturing looking at the screw from the _head_ end. On some cars and most trucks, the lug nuts on the left side are left-hand threaded. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [February 6, 2020, 6:11am UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/7 "2020-02-06T06:11:30Z")
> [@scr4](#): > > I guess I should have said, with a right-hand screw (which is most screws manufactured by humans\*), when you turn a piece clockwise, _the piece you are turning_ moves away from you. > > So when you turn a nut clockwise, the nut moves away from you. When you turn the bolt clockwise, the bolt moves away from you. Wow. I never thought to picture it this way. Put this way, the rule works for either piece (nut or bolt) AND whichever end of the bolt you are looking at. ---
**Author:** ![swampspruce](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/swampspruce/32/261_2.png) [@swampspruce](https://boards.straightdope.com/u/swampspruce)\ **Post date:** [February 6, 2020, 11:25pm UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/8 "2020-02-06T23:25:39Z")
Oh, thanks to this thread I now have a a Lamy Z28 converter and a bottle of J.Herbin Eclat to Saphir ink on its way via Amazon. If I don’t like it Imma gunna blame Y’All. 😃 ---
**Author:** ![swampspruce](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/swampspruce/32/261_2.png) [@swampspruce](https://boards.straightdope.com/u/swampspruce)\ **Post date:** [February 25, 2020, 5:09pm UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/9 "2020-02-25T17:09:42Z")
OK, everyone gets a praline chocolate chip oatmeal cookie! The converter and ink arrived and… it’s brilliant! The ink is smooooth and dries way more quickly than the stock Lamy ink, and the converter is super easy to use. Call me a convert! Now I may have to go shopping for another pen, or see if I can find my vintage Waterman or Cross pens somewhere in the dregs of the basement. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 25, 2020, 5:26pm UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/10 "2020-02-25T17:26:50Z")
I dropped my open fountain pen today onto some tile. Not a good result. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [February 25, 2020, 5:34pm UTC](https://boards.straightdope.com/t/why-are-fountain-pen-reservoirs-reverse-threaded/847515/11 "2020-02-25T17:34:41Z")
> [@swampspruce](#): > > OK, everyone gets a praline chocolate chip oatmeal cookie! The converter and ink arrived and… it’s brilliant! The ink is smooooth and dries way more quickly than the stock Lamy ink, and the converter is super easy to use. Call me a convert! Now I may have to go shopping for another pen, or see if I can find my vintage Waterman or Cross pens somewhere in the dregs of the basement. Uh, oh. What have we done? Whatever you do, don’t go to a pen show or a brick and mortar pen store (if you can find one). p.s. can you make one cookie without pralines? Allergic.