A Machine Shop That Once Built F1 Engine Parts Launches Its First Consumer Product: A Precision-Machined Metal Pen

SHAFT CRAFTS, crafted with 1/100mm fit tolerance by Kaiko Seiki, a precision metal-cutting company founded in 1937, launches a crowdfunding campaign on GREEN FUNDING for a limited run of 50 modular metal pens.

Tokyo, Japan - Kaiko Seiki Co., Ltd. (Headquarters: Itabashi-ku, Tokyo; President: Shinichiro Fushimi) today announced the launch of a crowdfunding campaign for SHAFT CRAFTS, a precision-machined metal writing instrument brand built on the company's decades of experience in metal cutting. The campaign runs from Friday, August 21 to Wednesday, September 23, 2026, on the Japanese crowdfunding platform GREEN FUNDING.

From F1 Engine Parts to Something You Can Hold

SHAFT CRAFTS applies machining techniques the company developed while manufacturing F1 engine components to an everyday writing instrument. Users combine interchangeable brass or stainless steel parts to assemble a pen with their preferred weight, texture, and grip. The inaugural project offers 50 limited sets for early adopters, with feedback from this first cohort shaping development of future models.

Kaiko Seiki was founded in 1937 in Itabashi, Tokyo, specializing in precision shaft-and-cylinder machining - components such as shafts and bolts for automobiles and industrial machinery, as well as prototype parts. In 1964, the company began working with Honda R&D, and as Honda's motorsport ambitions grew from motorcycles to four-wheel racing to Formula 1, Kaiko Seiki refined its precision manufacturing alongside them as a trusted technical partner.

As the shift to EVs continues to reshape demand for internal-combustion engine prototyping, Kaiko Seiki set out to carry its precision-cutting expertise into a new market - partnering with a designer to develop its first in-house consumer product.

1/100mm Fit Tolerance: Multiple Metal Parts, One Solid Feel

SHAFT CRAFTS is a modular metal pen built from a brass or stainless steel base combined with a knurled or polygon-cut grip section. Its defining feature is a fit tolerance of 1/100mm: when the parts are threaded together, they lock into what feels like a single piece of solid metal, letting users choose the weight and grip texture that suits them.

Conventional knurling is typically produced by pressing a patterned tool into the material to transfer a texture onto the surface. SHAFT CRAFTS instead cuts each groove individually, indexing the workpiece and synchronizing the feed of a rotary cutting tool to render the pattern within the grip's limited width. It is a far more labor-intensive process than efficiency alone would justify - but one the team chose deliberately, for the machined edges, the texture it leaves under the fingertips, and the way it catches light.

https://okunote.tokyo/shaftcrafts/

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Okunote is a Tokyo-based business design studio that partners with Japanese manufacturers, artisans, and regional businesses - and with international brands, retailers, and investors - to build new business, products, and brands. We support every step, from initial concept through to final design, and work with clients around the world in English and Japanese.

This release was published on openPR.