The work of expert metalworkers from the northwest of Japan is on show in an exhibition for London Design Festival.

Recently opened cultural space Japan House is showing around 300 metal objects – including cutlery, nails, hoes, scissors, teapots and pipes – in an exhibition called Biology of Metal: Metal Craftsmanship in Tsubame-Sanjo.

The display showcases the centuries-old skills of metalworkers in Tsubame-Sanjo, a small city near the Japan Alps region renowned for its beautiful and functional metal crafts.

Factories and small workshops in the city produce over 80 per cent of Japan's cutlery. The exhibition aims to shed some light on the processes behind its production, and to demonstrate how the industry has adapted in the 400 years that metal has been manufactured in the city.

Copper teapots and vessels made using the centuries-old tsuiki copper-hammering technique of the Gyokusendō workshop are on display. These items are each made from a single sheet of copper heated and hammered by hand.

Alongside the copperware will be razors made by Ryoichi Mizuochi from Sanjo Seisakusho workshop, the last craftsman making traditional Japanese razors.

These razors, called wagamisori, feature a steel blade sharpened to an extremely sharp edge on an iron bar. They were originally used by samurai to shave the tops of their heads leaving a small topknot of hair at the back.

Simon Wright, head of programming at Japan House, stresses that although the area's working population is shrinking, the market for this sort of metalware is not: "Although there is only one elderly man making handmade razors, there is a three-year waiting list. The demand is there."

The exhibition is inspired by the annual Tsubame-Sanjo Factory Festival (Kouba no Saiten) initiative. Each October factories and workshops in the area open their doors to visitors, to offer the opportunity to see craftspeople at work and to take part in metalworking themselves through workshops.

"I was inspired by my visit to the Factory Festival and by meeting a variety of craftspeople, designers, buyers, and city officials," Wright told Dezeen.

"I was impressed how a community was working together to promote the area's main industry – be it small one-man workshops or factories mass producing products. The element of social enterprise, and the importance put on the makers, workers, or craftspeople struck a chord."

The exhibition coincides with London Design Festival, which runs from 15 to 23 September, but remains open until Sunday 28 October.

The gallery will remain open late on Friday 21 September for a talk about Japanese blades by three leading craftsmen, including Mizuochi.

Dezeen has highlighted 12 picks for London Design Festival, including a poetry-spouting lion and an exhibition of furniture inspired by the drawings of modernist Uruguayan architect Julio Vilamajó.