The Space Zebra F-7401

As my username implies, I am always looking for the ultimate pen. I’ve found many that I’ve liked and a few I’ve hated, but I’ve thus far relied on the varying pen manufacturers to build me something and then I like it or don’t.

That changes today!

I was doing some reading in pen-related message boards and on Reddit, and in passing I heard a few people mention how great the Zebra F-701 is. I was skeptical because I had mixed experience with Zebras- some of them have been real duds but some have been quite exceptional. I looked it up: it had decent reviews, and I liked the all-stainless steel body and knurled grip. So I ordered one.

As soon as I got it, I was a little disappointed. As with some other Zebra ballpoints, the body of the pen was nice but the ink left a lot to be desired. It was too fine-tipped for me. It took too much pressure to write and scratched more delicate paper. A little dejected and let down, I put it back on my shelf for a later review on Penthusiast.

But then I caught a thread somewhere where they got talking about how well the Zebras take to mods- and the F-7401 mod. Intrigued and willing to experiment on a pen I wasn’t crazy about, I read on: evidently the plastic clicker on the F-701 has a penchant for breakage, but the Zebra F-402 had a stainless steel mechanism that was significantly more durable. Since the body of the 701 with the knurled grip far beats the rubber grip of the 402, all one needed to do was to pull them apart and put them together. Simple enough.

But that left the ink…. and as nice as an F-7401 was going to look, I still wasn’t going to write with it. But then someone tried a Fisher Space Pen refill- and it fit! Having recently lost my first Space Pen, I knew I had to do this. So I ordered a Fisher refill right away, and they all arrived today.

So if you’d like to make your own F-7401 Space Zebra pen, here is my step-by-step instructions on how to do it:

The Supplies

Zebra F-701 ballpoint pen
Zebra F-402 ballpoint pen
Fisher Space Pen refill
Bic lighter


Step 1: Disassemble the F-701

The F-701 comes apart pretty easily. Unscrew the tip and take out the ink, but make sure to keep the spring. The clicker on the back should also unscrew easily and come right out. Keep all the parts though- you’re going to need them.


Step 2: Taking out the… little plastic… thingie

A paperclip works fine here. I bent one side up and poked it in the front to remove the little plastic bit that’s in the front. This is the part that keeps the ink solidly in place so it won’t click when you write. Unfortunately, the Fisher ink cartridge is just a little bit bigger than the stock Zebra ones, so you need to stretch that out.

When you pop it out it looks like this:

Step 3: Stretching the thingie

If you take the Zebra ink and push it all the way up through it, it will stretch it out well enough to be able to fit the Fisher through. Pop it back in where it was in the tip when you’re done.

Now that the thingie is back in the tip your entire F-701 should look like this:


Step 4: Freezing the F-402

Unscrew the tip of the F-402 and take the ink out. You’re not going to need these parts and this pen is about to get a little banged up so you can put it aside.

You may have tried to unscrew the clicker on the 402, but couldn’t. I hope you didn’t try to use pliers, because all you’re going to do is scratch the stainless steel parts that you’re working so hard on getting out of this thing. No, unfortunately it’s not that easy- Zebra seems to seal this pen with some kind of plastic or glue that keeps the threads locked very tightly into place. Trying to force it is going to just break and destroy it, so don’t.

So what do we do? Use physics. Freeze it!

I kept mine in there for a couple hours, but that’s probably more than you really need. I’d think a half hour to an hour would be sufficient.


Step 5: Burninate

Now that the steel has gotten nice and contracted from the cold, it’s time to shock it a little bit.


Take it out of the freezer, light your lighter, and hold it right in the flame for about 15-20 seconds:

This picture is actually a poor representation of how you do it, but the best I could do while still taking a photo. It works best if you hold the pen right in the blue part of the lighter flame and just let it sit.

What’s happening is that the metal is contracted inside and out, but when you heat up the outside so quickly it expands much faster than the interior. This gives you a brief window to easily break the seal. So as soon as those 15-20 seconds are up, quickly unscrew the clicker (using work gloves because again, it’s REALLY HOT!)

When I did this it took a little force, but I was honestly surprised that it wasn’t too difficult to pop out. Once you get it out you can actually see the sealer they use in the threads- and it’s this stuff, unfortunately, that prevents the 701 parts from fitting into the 402 and making the pen usable again.

When disassembled it should look like this:

Step 6: Put it all together

  • Put the spring around the Fisher refill
  • Fit it through the tip
  • Put the clicker assembly on the back
  • Screw it all together


Step 7: You’re Done!

Here it is, all finished! The clicker is a little stiff but that seems to stem entirely from the plastic thingie and is getting better the more I use it. It feels great in my hand and it writes great.



Pen Modification: Success!

Posted on July 25, 2014, in Uncategorized. Bookmark the permalink. 12 Comments.

  1. Can’t believe I’m the first comment so many months later. I found your post via where someone else had also followed your instructions. Now there are at least 3 people walking around with F-7401’s in their pockets. If this keeps up your creation will lose its hipster vibe and I’ll have to start carrying an actual quill and ink to be different!

  2. After stretching out the thingie for fisher space ink cartridges, can you still use the stock Zebra ones?

  3. Great info, I’m really liking this pen. Couple items I could add:
    Using something rubber to unscrew the 402 helped a lot. Rubber washer, one of those old rubber things for unscrewing jars, whatever. Anything that can help you grip that little end you are trying to unscrew. Longer in the freezer the better/easier.
    Also, I used the same piece of rubber to cleanup the threads on the 402 after. If you clean that glue out you can reverse the process and use the original 701 clicker back in the 402 and still have a usable pen, if you wanted it. It was very easy to clean out.
    I used the clip from the 402, cleaner without any advertising.
    I found using wire cutters and cutting down the spring by about 1/3rd made the action nicer in the new pen.
    Very nice!

  4. Thank you for the instructions. They were a big help. I’ve been enjoying the 701 with the original 701 clicker and the space pen refill mod. Today I thought I’d try the next stage. My experience was a little different than yours. I thought I’d share how it went for me.

    First, as you suggested, 30 minutes in the freezer was sufficient to chill the pen. As it turns out, I’m not sure any freezer time is necessary since the metal threads of the 401 clicker are threaded into a plastic barrel. I think the heat is softening the plastic female threads allowing you to back out the clicker.

    Second, as you suggested, a lighter provides sufficient heat to do the job. My propane plumbers torch proved to be excessive and melted the plastic insert on the first 402 pen. My propane torch has a trigger that is easier to operate with gloves on than the lighter was but is overkill. I guess that is why the 402s come in a 2-pack. I got the second pen apart with just a little heat.

    Third, I couldn’t thread the 402 clicker into the 701. I inserted one side of a pair of needle nose pliers into each pen body and tilted it while pulling to bite and pull out a black plastic barrel insert. It runs the full length of the 701 pen body. I slid the rubber grip off the 402 before doing the same needle nose trick on it. Once I swapped the plastic barrel inserts, everything worked as described and the 701 took the 402 clicker. Also, I was able to put the 701 insert into the 402 barrel and put it back together with the 701 clicker – bonus pen.

    Thanks again for your instructions.

    In a future post, would you tell us about the broccoli pancakes in your freezer.

  5. Just been to Amazon to buy the two pens. I just love the look of the hybrid. Thanks for the idea.

  6. I did the mod, but my clicker sticks every time. I have to push the pen onto something hard to get the ink back in. Anyone have this problem?

    • I’ve run into this and have had 2 different ways to mitigate:

      1. Pull the plastic doohickey out of the tip and stretch it out further. Use a sharpened pencil and expand it out a ways, then put it back. The Fisher ink is thicker and needs a decent amount of wiggle room.

      2. Change the spring at the clicker. Whichever one you used, swap it with the other and see if it helps.

  7. Great mod, certainly makes the 701 perfect. My for the plastic insert in the tip is to snip a little of at the top. You will notice the “exit hole” has a bit of an inward taper, just at the end. I think this is the only portion creating resistance to the “final frontier” refill.
    I snipped off about 1/16th of the overall length, and not only does it feel nice and loose without sticking, I have never needed to stretch or re-stretch the insert.

  8. As Greek suggests above, trim the leading edge of the narrow end of the plastic insert just a tiny bit with a scissor. Like 1/32nd. That’s enough to let the Fisher refill pass through but not get loose when extended.

    Many folks also swap out the stainless pocket clip. Preferring the more substantial and unbranded 401 clip to the 701. Personally, I prefer the action of the springier 701 going in and out of a shirt pocket. But the 401 clip looks a bit nicer.

  9. from close inspection, it seems that the plastic thread inside the 701 actually runs the entire length inside the metal body. Has anyone else noticed this? It’s just that although everyone speaks about this being an entirely 100% metal pen hack… it isn’t quite… ! The pen is still awesome and the hack is really great. But thought I’d mention this for completeness.

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