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Ko-Axis™ Rail Pen - Aluminum Edition

$129.95 Regular price
Unit price
Graphite Black

$3 Shipping on all Domestic orders

FREE International Shipping on Orders Over $150

Abandoning the cylindrical shape of a traditional pen, the Ko-Axis™ Rail Pen leverages the benefits of a flat, wide, rectangular geometry for unparalleled writing comfort and ultra-low profile carry.

Rather than cramping your fingers around a thin cylindrical shaft, you can embrace your writing instrument in a more natural way that provides long term comfort with less tension on your fingers. The 4-1/2" length is optimized to deliver a fluid writing experience in your hand, yet be incredibly compact for convenient everyday carry.

The magnetic twin-rail mechanism used to extend and retract the ink refill eliminates the need for a separate cap. Combined with an instant, no-tool refill replacement method, the Ko-Axis™ Rail Pen will always be your pen of choice. Its elegance, comfort, and simplicity will make you wonder why this never happened sooner.

This aluminum edition is the featherweight member of the Ko-Axis™ Rail Pen family, and is coated in a hard-wearing Cerakote finish. Cerakote is a ceramic polymer based proprietary coating that offers industry leading durability, hardness, scratch resistance, corrosion resistance, flexibility, heat and chemical resistance.

Key Features

  • Flat geometry: The rectangular shape provides comfort during long writing sessions
  • 6 mm low-profile body (less than 1/4" thick) for discrete storage when carried or clipped
  • The perfect pen to accompany journals, notebooks, diaries, etc.
  • The embedded micro socket provides an "Instant", no hassle refill replacement that does not require tools: pull-to-remove/push-to-insert
  • Accepts a wide variety of commonly available D1 stylus refills, including Fisher pressurized refills (in case you want to write upside-down)
  • Unique, twin-rail skeletonized body is strong, lightweight and will make heads turn
  • Magnetic actuation and retention mechanism
  • Balanced design for the ultimate writing experience
  • No possibility of accidental ink retraction during use
  • Flat, anti-roll design stays where you put it
  • Symmetrical profile allows for identical writing comfort for both right and left hand usage
  • Assembled from 24 individual, custom machined and critically selected components, to ensure a high quality, bulletproof pen that will last a lifetime

What you get:

  • Ko-Axis™ Rail Pen
  • Integrated pocket clip
  • Premium Monteverde D1 ink refill
  • Refill Actuation: Magnetic Push/Pull
  • Refill Replacement: Pull-to-remove, Push-to-insert
  • Weight: 46 grams (1.6 oz)
  • Size: 6 mm x 109 mm x 22 mm (.236" x 4.29" x 0.866")
  • Height with clip: approximately 8.77 mm (0.35”)
  • Materials:
    • Body: Aircraft grade 6061-T6 aluminum
    • Guide rails: Solid stainless steel precision rod
    • Slider: Clear anodized aluminum
    • Pocket clip: 301 stainless spring steel
    • N52 Neodymium magnets with the highest magnetic strength/size ratio available 

The Ko-Axis Rail Pen is manufactured from a variety of materials to provide optimized functionality as well as a distinctive aesthetic. All components used in the production of this writing instrument go through a series of finishing processes (model dependent) including tumbling, polishing, anodizing and coating.

An integral component of every Ko-Axis Rail Pen is the “slider”, used to extend and retract the refill. This critical part is made from 6061-T6 aluminum and is clear anodized for long term protection and wear resistance. In addition to its light weight, it maintains a neutral color scheme that offers a clean appearance that doesn't conflict with the other component materials and finishes.

The following dimensions are in millimeters [inches]:


Form Factor

We've designed the Ko-Axis™ with a purpose-built, distinctive shape, sparing no detail. The comfort and ergonomics that were considered in the design phase are unparalleled, resulting in a truly unique writing experience. These features create an aesthetic that turns heads. All of these features have been packed into a pen so thin that it easily hides in any notebook. Be warned: once you write with the Ko-Axis™, you will never go back to a conventional pen.


Upon closer inspection of the Ko-Axis™ Rail Pen, you will discover that the aluminum grip slider contains the ink cartridge. By implementing this clever design, it is impossible for the pen to accidentally retract while writing. The ink refill is always present when you need it and never when you don't. We have painstakingly integrated eight ultra-strong neodymium magnets into the end stop positions to ensure perfect engagement, and eliminate any potential for movement of the mechanism while writing.

Writing Experience

The Ko-axis™ isn’t just a beautiful writing instrument, it transforms the act of writing into a wonderful experience. From the first time you extend the ink refill, you’re hooked. The rectangular shape of the Ko-axis™ rests gently in the crease of your hand and lands comfortably in your thumb-and-finger pinch. The shallow divot in the lightly textured slider offers the perfect spot for your pointer to land every time. The weight distribution of the pen was carefully calculated to rest in your hand without applying any torque to your fingers that would tire your hand in a late-night writing session. The Aluminum Edition is the featherlight member of the Ko-Axis™ family. The aluminum body allows the pen to float effortlessly across page after page. The Titanium Edition has 25% more mass than its aluminum brother, providing a solid and comfortable resilience that will last a lifetime. Every titanium model affords a rock-solid, stable action and exudes confidence in every word it writes.


The Ko-Axis™ Rail Pen includes a Monteverde D1/Multipen refill, which we think is the best refill on the planet. This medium point, black ink refill is the perfect way to experience everything the Ko-Axis™ has to offer. It features Soft Roll ink technology which is a low viscosity ink for the smoothest writing experience, with a high quality nickel silver tube and a Swiss tip.

However, any D1 style refill will work in the Ko-Axis™, including but not limited to the following:

  • Schmidt 635 Mini D1
  • Lamy Mini Ballpoint Refill M21
  • Kaweco D1
  • Monteverde D1/Multipen
  • Parker D1
  • Zebra Sharbo X Gel Ink Multi Pen/D1
  • Zebra ESB-0.7 Emulsion Ink Ballpoint Pen Refill - D1
  • Ohto R-4C7NP Needle-Point D1
  • Rotring D1 Multi Pen

TEC Accessories offers a 30 day no-questions-asked return policy on all of our products. If you are not satisfied with your purchase, for any reason, contact us to arrange a return/refund. In addition, all products carry a 90 day warranty against defects in materials or workmanship. Please contact us if you have any problem with your purchase that requires attention, and we will promptly make any necessary corrections.

Shipping Times

PLEASE NOTE: Due to the current logistics delays, shipping times may take longer than expected. This is especially true for International shipments, where delivery times can take weeks longer than usual. This is beyond our control, and we ask that you please be patient with expected deliveries until shipping companies get back to a more "normal" schedule.

We make every effort to process orders within one working day, however there may be slight delays depending upon the number of orders we receive, holiday periods and available staffing resources. Typically we will process all orders within no more than 2 working days.

Shipping times (from the time the package is dropped off at the carrier) will vary depending upon the carrier, method of shipment and destination. For example USPS Domestic First Class Mail should take between 2-3 days, but we have seen instances of 5-7 days. Domestic Priority Mail should take 1-2 days, but can take anywhere from 1-4 days. Domestic Express Mail should take one day, but that is only if your processed order is delivered to the post office before the cutoff time (typically 12:00 noon). Also keep in mind that weather and travel distance can have an effect on delivery times.

International shipments have even more variables that must be considered. A package sent by USPS First Class International can take anywhere from 1-3 weeks, sometimes longer depending upon the country. International shipments have the potential of being delayed by Customs, as well as having additional taxes or fees levied on a package. These are out of our control, and we advise that you become familiar with your specific country's shipping regulations to understand the impact to your shipment.

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Customer Reviews

Based on 15 reviews
Bobby Johnson
Great pen

I love these pens. I've bought every color, the zombie and the battle warn. Would love to have it in yellow.


Very cool pen.

Helio R.
The new Cerakote colors are awesome!

I bought one of the original black pens, but recently got the copper to match my EDC. LOVE the color!

Darrell B.
Just say "Yes"

I was on the fence about buying this, then finally pulled the trigger. Glad I did, pretty cool pen. I love the click of the magnets!

Michael V.
Nice but expensive

I do like it, but close to my pain point for buying a pen.