It is over 22 years since family company Linder Aluminiumboats and its founder Lars-Göran Linder started making canoes out of aluminium instead of glass fibre. Shortly after that, the company also began using aluminium in its small boats.

“Aluminium canoes had started appearing on the market, and the material offered several advantages. The benefits for the working environment were particularly important to us,” says Jessica Linder, marketing manager of Linder Aluminiumboats.

The decision proved a successful one. Many people – especially in boat rentals – discovered the benefits: the material ensures the boats/canoes are durable and maintenance-free, as well as economical and easy to handle (thanks to the low weight). Nowadays, Linder Aluminiumboats in Tingsryd, southern Sweden, is the biggest manufacturer of aluminium boats in Sweden – and one of the leading suppliers of small boats in general.

Meeting Linder standards
Bulten Stainless has been a supplier of fasteners all the way.

“Of all the screws we buy, probably around 95 per cent come from Bulten Stainless. We’re very pleased. The products are always of consistently high quality,” says purchasing manager Stefan Ottosson.

The product Linder has chosen is a high-strength screw made of Swedish steel 2343.

“We’ve looked at other suppliers but they don’t come up to scratch. No other screw can cope with the torques we have to deal with.

“What’s more, Bulten Stainless provide excellent service. They’re one of our best suppliers. The deliveries arrive in time and we always get clear answers to any queries. Communication with us as the customer has been excellent.”

Environmentally friendly screws
Linder makes its boat and canoe hulls with a method called stretch forming, a technique originally used in aviation. The aluminium plates are stretched by hydraulic cylinders in a special machine, and bent over a template into a boat-half. Finally the left and right halves are screwed together.

“We like our boats to have a softer line. This is why we use stretch forming,” says Jessica Linder, talking about the technique which the company has fine-tuned itself.

Other manufacturers of aluminium boats weld or rivet their products. But Linder continues to use the same fastening solution as used for plastic canoes over the years: screws.

• Why do you prefer this technique?
“Riveted aluminium boats have a tendency to leak. Also, using screws has less of an impact on the environment than welding,” says Jessica Linder.

The company produces some 1,800 boats and 1,100 canoes a year. Reports of the products’ high quality have reached overseas, and today around half the vessels are exported – some as far afield as Japan and India.

Products from Bulten Stainless AB
No. of screw types: 12 different types of Torx screw, four different nuts.
Dimensions: M4, M5 and M6.
Steel grade: Swedish steel 2343.

Facts about Linder Aluminuimboats
Business: development, production and sales of Linder aluminium boats and Inkas Canadian aluminium canoes.
No. of employees: around 20.
Net turnover: SEK 29 million (2003).
Site: Tingsryd, southern Sweden