Raising quality levels
When Svenska Uni-Cardan AB launched the globally unique Aquadrive, it won the justified attention of the marine industry. An annoying corrosion problem, however, with the Aquadrive’s fasteners upset the picture. The solution came from Bufab Stainless – in the form of the acid-proof, high-strength BUMAX screw.
Håkan Persson, purchasing manager at Svenska Uni-Cardan AB, is extremely pleased with the acid-proof Bumax screws from Bufab Stainless. The screws are used in the globally unique Aquadrive – an anti-vibration system which is connected to the engine and propeller shaft of boats.
Aquadrive is an anti-vibration system enabling the propeller shaft to be angled against a boat’s engine with the following advantages:
- Simpler installation of the propeller shaft
- Less vibration on board the boat
- Lower noise level
The fitting of the propeller shaft to the engine is a difficult stage of boat building. The engine and the propeller shaft must be positioned with extreme precision in order to be exactly in level with each other. Aquadrive provides space for easier fitting, which saves time and money.
From Carbon steel to stainless
“We underestimated the effect of salt water on the fasteners in the product. Initially, we used the conventional Carbon steel screws which eventually resulted in the corrosion problem,” says Håkan Persson, purchasing manager at Svenska Uni-Cardan in Stockholm.
Since the Aquadrive unit is painted dark green, a gold-chromed screw was sourced; a “golden yellow” colour. “We thought it would go well with the new green colour. But we had quality problems with the screw, so we started looking for an acid-proof alternative,” relates Håkan Persson.
The stresses on a product in a marine environment can be enormous, not least regarding corrosion attack. Svenska Uni-Cardan contacted several suppliers of stainless, high-strength screws. “But it was really only Bufab Stainless in Svartå that could supply the whole range we needed.”
Not a single complaint
The solution was Bumax – a wide range of fasteners with unique properties and high strength qualities. Stainless and acid-proof properties are as good as imperative in the marine industry, which is very much a sales argument for Svenska Uni-Cardan.
“We are very pleased. We haven’t had to send a single screw back,” says Håkan Persson.
In fine company
Aquadrive is designed mainly for pleasure boats measuring 30-80 feet with engines of up to 1,500 kW. Some of the world’s best-known boat builders – Fleming Yacht, Hinkley, Grand Banks to name but a few – use Aquadrive as standard. Bumax also meets all other requirements set by Svenska Uni-Cardan.
“The first positive impression has been confirmed and reinforced. Bufab Stainless took exemplary good care of us. Delivery reliability is extremely high which is very important to us,” says Håkan Persson.
Products from Bufab Stainless AB
Number of screw types: 36 Steel grade: Conforming to Swedish SS 14.2343, EN 1.4436 with low carbon content
Also: All fasteners supplied are class Bumax 109 and 88.
Facts about Svenska Uni-Cardan AB
Owned by: Part of the British GKN Group which also owns Westland Helicopters
Own products: Aquadrive - anti-vibration system for boats. Bonair – Air conditioning for driver environments (trains, tractors, cranes etc.)
Other products: drive shafts, clutches and various parts for the transfer of mechanical force in vehicles and in industry.
Sites: Stockholm (production and sales) and Malmö (sales)
Turnover: Approx. SEK 110 million (1998)
No. of employees: 65
Facts about Aquadrive
Area of application: boat engines up to 1,500 kW
Positioning: unit between reverse gear and propeller shaft enabling the propeller shaft to be angled against the engine
Effect: vibration and noise-damping
Launch: 1982
Markets: 80% export, mainly the USA, then Holland, the UK, Singapore and Taiwan.