Ballpoint pen plug source?

I’m looking for a source for the little plug that is found on the end of cheap ballpoint pens. These little plugs are a perfect fit for an application I have, but I’m limited to the three cheap pens I found around the house and whatever others I run across in the next few days.
How can I find where these things are made, a supplier, etc.? Googling has shown me a plethora of pen manufacturers, but I’d love to narrow down my search a bit.
Any ideas?

You accurately measure the thickness with a digit caliper and then order the same size dowel rod in the material of your choosing. Cut off pieces as needed.

How much are you willing to spend? I remember getting a decent sized bag of cheap pens from CVS for $2 once. I’m sure there are even cheaper places if you buy in bulk and avoid name brands. Might be easier than finding the plugs themselves, and you’ll have all your ballpoint pen needs filled for years.

Trying to find that specific product will be a fools errand. And the cost of it in production is nearly nothing so there is nobody going to make them available to you. There’s nothing in it for them. You need to think out of the box.

Could you use a cut cue-tip?
How about hot melt glue or other glue?
Maybe a 2-56 screw?
Piece of a pipe cleaner?
Kid’s silly putty?
Epoxy (because it does not change size when dry)?
Tiny rolled up piece of toilet paper?
Cut piece of solder?
Cut piece of wire? (stripped or unstripped)
Anything you have available?

Al Bundy, I am 100% on board with you as far as thinking outside of the box. Let me give you a little background info on my application:
I make a special tank designed to display jelly fish. There is a spray-bar that induces flow around the tank. I’ve tried sealing the end of the spray-bar with a silicon plug, and ultimately have wound up gluing an acrylic ball in the end. The problem is, the spray-bar has holes in it that get gunked up with particulates. I’ve been looking for a removable plug or end-cap so I can get in there with a pipe-cleaner to get things squeaky clean.
I’d been thinking of something along the lines of a pen end-cap and low and behold… I just happened to be writing with an old promotional pen yesterday. I got to wondering if there was the slightest chance the pen would have the same inside diameter as my spray bars. A dozen emptied drawers and three junky old ballpoints later and it turns out these end plugs are all pretty universal and fit my needs perfectly.

Waterj2, I’m planning on hitting up my Grandmothers place later in the week. She’s got about 50 years worth of junky pens laying around which will do me just fine for the time being, but I’d love to find a source of the clear plastic ones I dug off of one of my pens.

Thanks for the inspiration everyone, I’m open to anything that will fit my needs. All ideas are welcomed.

If this were a vacuum line on a vehicle, you could plug it with a golf T. What you have it too small for that, but something else that is long and tapered would work and allow easy R & R for cleaning.

Maybe there is a possibility of just pinching the line off. This could be done with a paperclip, paper clamp, small C-Clamp or Vise-Grip type tool. The medical industry uses a finger operated plastic clamp that rolls over the tube to regulate flow from maximum to nothing. Those would be available at a medical supply and not too expensive either.

I’m convinced you will find something as you sound like an inventor.

My vote, too. I’ve actually done this (with a sketchbook-making project). Cheaper in the long run… especially when you factor in the running-around-finding-supplies time. I mean, if you add the cost of spending hours tracking down The Perfect Plug at $10-20 an hour, how much are those plugs costing now?

The makers of the pens probably own the molds that make the parts. Sometimes manufacturers buy parts from another firm that sells the parts and make their product work with that supplier, but I doubt that’s the case with the internals of pens other than the ink cartridge. Contact the pen maker to see about the part. It is common for manufacturers to send their tools out for external molding, but they still normally own the tool and the rights to using it to make parts. There is of course no restriction for buying something retail and using it.

Try looking at drip irrigation tubing supplies. They sell plugs for the ends of the lines that might work for you.

If you’re talking about a round tube then you could put a small length of clear vinyl hose on the end of that and plug that. This gives you an end fitting that will stretch around a variety of improvised plug sizes and allow you to use the closest acrylic dowel rod size that works.

You could also surf the net looking for companies that specialize in plugs.

Note the pull plugs listed here.

Bic ballpoints go for something like eight for a buck. For the scale of production that you’re looking at, it might be cheapest to just buy pens, break them and push out the plugs.

Again, thanks for all the ideas everyone. Magiver, your links are actually closer to what I was hoping to find with this thread. All I need is something that will fit, and since the b.p.p. plugs worked perfectly, b.p.p. searches were all my one-track mind could come up with while googling last night.
I’ll look through those links and see how ordering something specialized will compare cost-wise to just picking up a pack of pens at Big-Lots…

Something else you can look for is a surplus store. We have a mammoth one in my town but you would have to search manually for the stuff as they have no way of advertising all the industrial crap they have. I can’t tell you how many times I’ve looked for some bizarre bit of something and found buckets of it.

Seriously, if you have a surplus parts store then grab your ipod and wander through it.