After decades of helping motorsport machinery move very quickly, one Japanese machine shop has redirected its precision engineering toward helping ink travel slowly across paper. Meet Shaft Crafts, a modular metal pen from Tokyo’s Kaiko Seiki Manufacturing.
Founded in Itabashi in 1937, Kaiko Seiki specializes in precision-machined shafts, bolts, prototypes, and automotive components. It began working with Honda’s research and development division in 1964. With electrification changing the market for prototype combustion-engine parts, the company decided its machining expertise deserved a new vehicle. That vehicle is a pen.
SHAFT CRAFTS combines interchangeable brass or stainless-steel components, offering a choice of weight, material feel, and grip. Options include a crosshatched knurled grip and a faceted Polygon design. The components are machined to tolerances of 0.01 mm, so tightening everything together produces the satisfying impression of one solid chunk of metal.
Even the knurling receives excessive—in the best possible way—attention. Instead of pressing texture into the surface, Kaiko Seiki machines each groove for sharper ridges and stronger reflections. Clearly, ordinary knurling was not sufficiently motorsport.
The 120 mm-long pen measures 12 mm across and weighs approximately 76 g in stainless steel or 81 g in brass. It accepts Parker-style G2 refills, while its cap can be moved to the rear.
Only 50 sets are being offered through Green Funding [JP]: 25 brass sets at 39,800 yen before tax (about US$250) and 25 stainless-steel sets at 49,800 yen before tax (about US$313). Delivery is expected in January 2027. It may not improve your handwriting, but your shopping list will possess race-engine tolerances.
