Research institute CERN signs contract with Swedish stainless steel fastener specialist BUMAX

Leading Swedish manufacturer of premium stainless steel fasteners BUMAX has signed a contract with scientific research institute CERN for more than a quarter of a million high strength premium stainless steel fasteners to be used for the upgrade of the world famous LHC particle accelerator in Switzerland.

The world’s largest and most powerful particle accelerator, CERN’s Large Hadron Collider (LHC), is currently undergoing an upgrade that will increase its energy up to 14 trillion electron volts and is expected to take two years.

The LHC collider is located at the particle physics laboratory at CERN near Geneva, Switzerland. It consists of a 27-kilometer ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. To avoid resistance or loss of energy, the several thousand magnets need to be chilled down to ‑271.3°C – a temperature colder than outer space and less than two degrees above absolute zero.

After tests, CERN opted to use BUMAX 109, the strongest A4 fastener on the market, to cope with the extreme conditions inside the collider. All the fasteners in the collider will be replaced and all of these fasteners are BUMAX 109. BUMAX will supply 130,000 fasteners to CERN each year of the maintenance project – equating to more than a quarter of a million fasteners in total.

“We are extremely happy and proud to be awarded such a prestigious assignment from CERN, to supply one of humankind’s most advanced constructions with instrumental parts,” said Patrik Lundström Törnquist, Managing Director, BUMAX. “It is definitely one of the most demanding and challenging applications you could ever imagine, and we are confident that our premium products are up to the task – and once again prove that BUMAX fasteners are the best of the best.”

Customer collaboration around silver coating

Scientists at the CERN particle accelerator required high-strength fasteners, with a low magnetic permeability and low cobalt content for their various vacuum chambers and bellows modules. Additionally, the fasteners need to withstand near absolute zero temperatures, down to 1.9 degrees Kelvin (minus 271°C), as well as high temperatures during bake-out (300°C). BUMAX 109 was deemed the best to fully meet all of the requirements including, crucially, non-interference with the movement of particles and magnetic field in the accelerator due to their non-magnetic nature. 

BUMAX collaborated with CERN to successfully trial the use of silver coating on BUMAX products to reduce galling, a form of mechanical wear caused by adhesion between sliding surfaces. Since these trials with CERN, BUMAX has started to offer silver coating to other customers with the norm CERN 507.

BUMAX is a world-leading specialist manufacturer of premium stainless steel fasteners in a variety of steel grades, including the world’s strongest stainless steel bolts.

Established in 1954, CERN (the European Organization for Nuclear Research) operates the largest particle physics laboratory in the world. CERN’s main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research. CERN is also the birthplace of the world wide web.

About BUMAX:
BUMAX is the world-leading specialist manufacturer of premium stainless steel fasteners in a variety of steel grades that provide optimal safety and reliability in the most demanding customer applications. Customers include CERN, ABB, Alfa Laval, Alstom, Vestas, Rolls Royce and many more in industries such as marine, automotive, oil and gas, chemical processing, energy, defense, pulp and paper, construction and general engineering. BUMAX is headquartered in Åshammar in Sweden’s steel district and has a global footprint with offices or distributors in more than 30 countries on four continents. BUMAX is fully owned by the listed Swedish Bufab Group. Find out more at