BQ-Steel® (Bearing Quality) has for many decades been driven by the bearing industriy. It is optimized for fatigue strength by a strict control of steel cleanness. The same approach to fatigue performance is now being applied in many other applications.

The extended performance, higher loads, and high cleanness are a result of the Ovako clean steel program. Purity of production means that the material has significantly smaller inclusions compared to conventional steel and, as a result, the fatigue strength of the steel is increased dramatically.

Reduced component size and increased load are problems that today's manufacturers face when energy savings, better resource utilization and demands for lower operating weight. High strength and high fatigue resistance facilitate the manufacture of components to meet the requirements of today and tomorrow. This is true for industries where high cyclical loading is an issue.

informative image: BQ-Steel

Advantages of BQ-Steel®

  • 30–90 percent higher bending fatigue strength in simple load cases, depending on steel used today
  • Up to 70 percent higher bending fatigue strength in multiaxial load cases, depending on steel used today

Factors affecting fatigue

Steel quality can have a tremendous impact on the fatigue life of a component. In conventional steel, non-metallic inclusions can be as large as 100 µm or even bigger. As varying loads are applied these large inclusions may initiate fatigue cracks if they are found in a highly loaded area, leading to material failure.

Continuous research and development by Ovako saw the introduction of a clean, bearing quality steel with inclusions typically less than 20 µm. Correspondingly, the fatigue strength of BQ-Steel falls between 600 to over 800 MPa, depending on loading direction, while that of conventional steels falls between 300 to 500 MPa. The rolling direction has a strong influence on fatigue properties for most steels. BQ-Steel is no exception. For an improved isotropic performance, we recommend IQ-Steel instead.

Unique analysis of the influences of defects in steel has allowed Ovako to build an extensive database invaluable in the development of clean steel. The resulting fatigue performance provides opportunities for manufacturers to rethink design solutions, allowing weight reductions of a component through an increased power density.

informative image: Steel fatigue failure
informative image: Ovako R&D

Ovako customer service

The BQ process can be applied to all our steel grades. We work closely with customers to optimize the steel supply chain to meet customers’ requirements, including multiple product packages. The material is available in tubes, bars, wire and rings.

Our services are underpinned by a detailed understanding of the industrial applications of our products, while paying as much attention as possible to your needs with regular direct contact. Ovako can advise you on how to best implement BQ-Steel for components in demanding applications.

Eleiko x Ovako

For several decades, Eleiko’s barbells have been made from BQ steel produced by Ovako, a leading European producer of quality steel. Ovako uses a process that sharply reduces the number of micro inclusions or the imperfections that may compromise the strength of steel. As a producer of bearing steels for the automobile industry, where ball bearings are under intense stress for long periods of time, Ovako is highly regarded.


Steel Navigator - Find the right steel for your application

Steel Navigator contains a selection of useful tools such as Material Data Sheets, Machining Calculator, Heat Treatment Guide, Piston Rod Predictor and more.

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Steel Navigator - Find the right steel for your application