BQ Steel and IQ Steel
PURITY CREATES DESIGN OPPORTUNITIES
The performance and durability of critical components depend heavily on the purity and consistency of the BQ Steel and IQ Steel used. For components and systems to withstand demanding loads over extended periods, it’s not enough for a steel to simply perform well — it must perform reliably, every time. This is where BQ-Steel® and IQ-Steel® from Ovako deliver real advantages. These specially developed steel grades offer superior metallurgical properties, giving engineers and designers the confidence to push boundaries and design with precision.
Over decades of innovation, Ovako has led the way in producing engineering steels with exceptional fatigue resistance and tight property tolerances. Their proprietary BQ and IQ performance levels can be achieved across a wide variety of grades, tailored to meet the most exacting industry demands.
No matter what grade you require, it’s essential to clearly define your expectations from the outset. Broadly, these expectations fall into three categories: direct cost efficiency, direct value creation, and long-term end user value. BQ-Steel® and IQ-Steel® are designed to meet and exceed expectations in each of these areas, offering predictable, high-performance results in both volume production and specialist applications.
Independently of which steel grade you need, it is important to define what you demand from the steel you acquire. In simple terms, this divides into three categories
1. Direct cost efficiency
2. Direct value creation
3. End user value creation
The key to their performance lies in the steel’s internal purity and inclusion control. Fatigue resistance improves dramatically when the steel contains small, well-distributed, and tightly controlled inclusions. BQ-Steel® and IQ-Steel® represent the upper levels on what is often referred to as the “fatigue ladder” — a term used to describe increasing fatigue strength in relation to metallurgical quality.
IQ-Steel® takes this a step further by delivering isotropic properties, meaning it performs equally well under load in all directions. This overcomes one of the limitations of conventional steel, where directional strength differences can limit design options or introduce hidden weaknesses. With IQ-Steel®, designers can approach projects with new levels of freedom and confidence, knowing that the material will behave consistently no matter how the load is applied.
Common grades with BQ and IQ-Steel performance
| EN-standard | Ovako | Comments | C | Si | Mn | Cr | Mo | Ni | Other |
|---|---|---|---|---|---|---|---|---|---|
| 20MoCr4 | 124 | Carburizing steel for heavier sections. available as IQ | 0.20 | 0.2 | 0.8 | 0.5 | 0.4 | ||
| 20N CrMo2-2 | 152 | SAE 8620 available as BQ | 0.20 | 0.3 | 0.9 | 0.6 | 0.2 | 0.5 | |
| 20N1Mo9-7* | 158 | Steel giving reduced surface ox dat1on after gas carburizIng, available as IQ | 0.20 | 0.1 | 0.3 | 0.4 | 0.7 | 2.3 | |
| 18CrNiMo7-6 | 159 | Carburizing steel used for bearing and transmission components, available as both IQ and BQ | 0.18 | 0.2 | 0/6 | 1.7 | 0.3 | 1.6 | |
| 20MnCr5 | 236 | For small-sized transmIssIon components, mooerate core Hardness, avaiable as IQ | 0.20 | 0.2 | 1.3 | 1.2 | |||
| 12NiCr14-6* | 245 | SAE 3311, available as BQ | 0.13 | 0.3 | 0.5 | 1.5 | 0.1 | 3.3 | |
| 18NiCrMo14-6 | 255 | High hardenability carburising steel, available as both IQ and BO | 0.18 | 0.3 | 0.5 | 1.4 | 0.2 | 3.3 | |
| 16CrMnN1Mo9-5-2• | 277 | Steel suitable for carburizing and nitriding Possible to gas/air harden. available as IQ | 0.16 | 0.2 | 1.3 | 2.1 | 0.5 | 0.5 | V |
| 42CrMo4 | 326 | SAE 4140, available as BQ | 0.40 | 0.3 | 0.8 | 1.1 | 0.2 | ||
| 40NICrM07-3' | 355 | SAE 4340 modified with V, available as BQ | 0.40 | 0.3 | 0.7 | 0.8 | 0.3 | 1.8 | V |
| 32CrMoV12-1 0 | 398 | Steel suitable for deep nitriding, available as IQ | 0.32 | 0.3 | 0.5 | 3.0 | 1.0 | V | |
| 42N1S1CrMo8-7· | 497 | High-strength. high-toughness steel known as 300M, available as IQ | 0.42 | 1.6 | 0.6 | 0.7 | 0.3 | 1.7 | V |
| 30NiCrMo 16·6 | 498 | High-strength, high-toughness steel, available as IQ | 0.30 | 0.3 | 0.5 | 1.4 | 0.2 | 4.0 | |
| 30MoCrV20-7* | 499 | Temperature resistant carburizing steel | 0.3 | 0.2 | 0.3 | 1.7 | 1.8 | V | |
| 50CrMo4 | 528 | Medium carbon Q& T steel suitable for surface induction Hardening, available as both IQ and BQ | 0.51 | 0.2 | 0.7 | 1.0 | 0.2 | ||
| 51CrV4 | 593 | High strength alloyed with chromium and vanadium, available as IQ | 0.51 | 0.3 | 0.9 | 1.1 | V | ||
| 66SIMnC rMo6-6-4 • | 677 | Bearing steel suitable for gas/air hardernng, available as both IQ and BQ | 0.67 | 1.5 | 1.4 | 1.0 | 0.2 | ||
| 100Cr6 | 803 | The most widely used bearing steel with a hardenability for small components (wall thickness 17 mm). available as both IQ and BQ | 1.00 | 0.3 | 0.3 | 1.4 | |||
| 100CrMo7 | 824 | Increased hardenability with Cr and Mo for small-and medium-sized components (wall thickness 20 mm). available as both IQ and BQ | 0.95 | 0.3 | 0.3 | 1.7 | 0.2 | ||
| 100CrMo7-3 | 825 | Increased hardenability with Cr and Mo for medium-sized components (wall thickness 30 mm), available as both IQ and BQ | 0.95 | 0.3 | 0.7 | 1.7 | 0.2 | ||
| 100CrMo7-4 | 826 | Increased hardenability with Cr and Mo for Medium-and large-sized components (wall thickness 50 mm), available as BQ | 0.95 | 0.3 | 0.6 | 1.7 | 0.4 | ||
| 100CrMnMoSi8-4- | 827 | Increased hardenability with Cr, Mo and S1 foe large-sized components (wall thickness 75 mm). available as BQ | 0.95 | 0.5 | 0.9 | 1.9 | 0.6 | ||
| 1 00CrMnS14-4 | 831 | Increased hardenability with Cr, Mn and Si for small and medIum-sized components (wall thickness2 0 mm). available as BQ | 0.95 | 0.6 | 1.1 | 1.0 | |||
| 100CrMnSi6-6 | 832 | Increased hardenability with Cr. Mn and S1 for medium sized components (wall thickness 40 mm). available as BQ | 0.90 | 0.7 | 1.5 | 1.4 | |||
| 100CrMnSi6- | 837 | Increased hardenability with Cr, Mn and Si for small and Medium-sized components (wall thickness 30 mm). available as BQ | 0.95 | 0.6 | 1.0 | 1.5 |
DIRECT COST EFFICIENCY
In practical terms, IQ-Steel® matches or exceeds the fatigue performance of some of the most advanced remelted steels on the market, while significantly reducing scatter in test results. In controlled tests, it has even outperformed standard ESR (Electro-Slag Remelted) steels, offering exceptional fatigue strength alongside greater consistency across large batches of components. The result is a material that enables tighter tolerances, fewer rejects, and better long-term performance.
Another major advantage is cost. Unlike traditional remelted steels, IQ-Steel® is produced cost-efficiently in high volumes, making premium metallurgical performance more accessible. This makes it possible to design smaller, lighter components without sacrificing strength, reducing both material and production costs. In short, you achieve more strength per kilogram and better value per unit of load.
BQ-Steel® also provides significant benefits where improved fatigue life and reliability are critical but without the additional isotropic benefits of IQ-Steel®. Both products contribute to more efficient, durable, and high-performance end-user components across sectors such as automotive, power transmission, energy, and precision engineering.
At Midland Special Steels, we work closely with our partners to provide advanced material solutions like BQ-Steel® and IQ-Steel® to customers who demand more from their materials. If you’re looking to reduce costs, enhance performance, and improve consistency in your production process, get in touch with our team to explore what these steels can offer your next project.
Advantages of BQ-Steel and IQ-Steel
• Consistent quality for secure and stable product.on of end-user components
• Improved bending and contact fatigue strength
• Increased load per weight capacity, e.g. Nm/kg
• Decreased cost per load unit, e.g. €/Nm
• Component size reduction at fixed torque
The price of the IQ-Steel produced cost-efficiently in high volumes is significantly lower than the competing remelted solution. In Figure 2 the principal relationships between the steel price and fatigue performance versus metallurgical routes are displayed.
