The Bona Fide Machined Pen

The Bona Fide Pen is a machined pen with a traditional style
and has the quality and strength to be your every day carry pen.

Overview

Every day, we use pens in our work and personal lives. The Bona Fide Pen is a writing instrument designed for people that appreciate the quality and durability of machined pens and enjoy using them. The ergonomic design of the Bona Fide Pen combined with it’s sturdy construction makes this pen an excellent choice as your every day pen. I hope this pen becomes part of your every day carry gear.

 

I enjoy using a quality fountain pen at my desk. I wanted a pen that had the feel and classic styling of the pens I was already using, but also had the durability and strength to withstand the abuses of being used everyday, outdoors and in the field. I wanted a pen that was quick to deploy and return to my pocket with one hand. For this reason, the Bona Fide Pen needed to be a retractable pen. I also wanted a pen that used refills that could meet the diverse needs of the user and were readily available. Like the name Bona Fide suggests, this pen had to be genuine, reliable and built to earn your trust. It’s Bona Fide!

Materials

Because I wanted a sturdy pen, it had to be made entirely of metal without the use of any plastic. I experimented with stainless steel, aluminum, brass, copper and even titanium. The steel, brass and copper make beautiful pens but the weight of those metals proved to be too heavy for prolonged use.

I finally decided on 6061 aluminum that had the best combination of machinability, strength, corrosion resistance and cost. 6061 aluminum will also accept a durable protective anodized finish that will keep the pen looking great even after years of use.

Design

Here is the criteria I used while designing this pen: 

  • Appealing classic style
  • Ergonomic pen geometry
  • Quality materials and construction
  • Precision fit and feel
  • Comfortable to hold and use
  • Dependable retracting mechanism
  • A good variety of popular refill options
  • Good price/value ratio

The starting point for the design of this pen was with the grip section. I like the way traditional fountain pens taper in towards the tip and then flare out again. This shape provides your fingers with a comfortable position properly spaced from the tip for writing and drawing. It also prevents your fingers from sliding down. Pens with sharp grooves or knurling can be irritating after prolonged use.

The undercut concave tip is inspired by the traditional nib shape found on fountain pens and adds style, strength and a clear view of where the tip meets the paper.

The Bona Fide pen is made with two slightly different designs machined into the barrel portion. The ‘pinstripe’ design has seven thin lines spaced 45 degrees apart along the barrel. The ‘stars & stripes’ design has the same lines as the ‘pinstripe’ style with the addition of eight evenly spaced stars, one above each of the seven pinstripes and one above the pocket clip.

The two piece body of the pen is built strong with robust M10 threads and an extended shoulder to ensure smooth, positive alignment where the pen barrel and grip section meet. I chose the M10 x 1.0 thread because it has a pitch diameter that perfectly splits the distance between the inner wall and the outside of the pen. This provides the greatest overall strength where these parts connect.

We looked at a number of retracting mechanisms with the goal of finding one that was precision made and extremely durable. I consulted with Jack Roman (a great guy by the way) of Tuff Writer MFG who has agreed to supply us with his superior retracting mechanism. This American made Tuff Writer mechanism surpasses all others in quality and reliability and features an improved raceway and 416 stainless steel construction.

The spring is custom made in the USA to our specifications from 316 stainless steel.

The Clip

The pocket clip on the Bona Fide Pen is made from 301 spring stainless steel and was specifically designed for this pen. The clip is laser cut and brake formed right here in Southern Oregon. The clip is then deburred and hand finished. Finally the clip is rigidly mounted to the pen in a close tolerance precision cut recess with two #2-56 stainless steel screws. Having the clip in a recess prevents the clip from moving and getting loose. 301 spring stainless steel resists corrosion and maintains its shape and spring retention. The clip has a slight pre-load tension and will be secure in your shirt or pants pocket or in your notebook.  

Machining

The Bona Fide Pen design required a machine that can produce small, complex precision parts. I worked with Jay MacDonald of Precision CNC Products, also here in Grants Pass, Oregon, and chose the Star CNC Swiss-type Automatic Lathe to manufacture the pen.

We were able to make the pen barrel and grip section with all the design features I wanted while maintaining precise tolerances and a beautiful machined finish that was ready for anodizing.

Finishing 

The pen barrel and grip section are then inspected for fit and finish. After the machined aluminum parts are inspected they are anodized to give the pen a resilient finish that will keep the pen looking great and performing perfectly. Anodizing is an electro-chemical process that converts the metal surface into a decorative, durable, corrosion resistant, aluminum oxide finish. We anodize in silver, black, blue and gold.

Ballpoint Refills

When deciding on which refill the Bona Fide Pen would be designed to use, my first candidate was the pressurized refill made by the Fisher Pen Co. The Fisher Space Pen refill is a popular choice because of it’s ability to write upside down and write on slick surfaces. It is a great choice for people who work and write outdoors.

Realizing that users of this pen will have different preferences, I wanted to be sure this pen could accept a wider variety of refills that met different needs. I eventually modified the pen design to accept refills that conform to an industry standard, the Parker DIN ISO 12757 specification. The Fisher Space Pen refill also works perfectly in this pen when used with the Parker adapter that comes with the Fisher refill.

While reviewing the many refills available I came across the Schmidt easyFLOW 9000 refill. This highly rated ballpoint refill makes a smooth and solid line much like a rollerball. The Bona Fide pens will be delivered with two Schmidt easy FLOW 9000 refills, one black and one blue.

 

Balance

We had a question about the pen balance. Here is a photo to show the balance point of the pen by itself. The pen has a neutral balance feel in average sized hands. I have large hands and when writing I find the pen rests slightly on my fingertips if I release my grip.