High edge (HE) ductility HSLA steel
High edge ductility HSLA steel with greatly improved local formability and high hole expansion ratios – ideal for challenging auto components with complex designs on sheared stretched edges.
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What is the definition of high edge ductility steels?
Unlike conventional HSLA steels, high edge ductility steels have a much finer microstructure and perlite distribution. This microstructure provides for higher formability, tighter radii bending, and crack-free sheared cuts – even on stretched edges. HE steel’s advanced microstructure is achieved by using exceptionally clean and closely controlled steelmaking processes. The high edge steel also has a low alloy content, making welding straightforward using conventional processes.
Left: Standard MC/LA grade. Right: HE grade HSLA.
Steel properties
An improvement of 30 percentage points in hole expansion ratio compared to conventional HSLA steels.
- Greatly increased local formability, providing ductility for complex geometries on stretched edges.
- Excellent cut/sheared edge quality, significantly reducing micro cracks and burrs.
- Bending radius of 0.0 xt can be achieved.
- Excellent for fineblanking and energy-efficient cold-forming of automotive parts with complex edges.
HE can help you solve part defects such as micro cracks on stretched punched holes and cracks on outer edges.
Auto applications for high edge steels
When a design needs higher edge ductility than provided by conventional HSLA grades, we recommend Docol HE.
- Beams and cross members
- Suspension systems
- Chassis
- Wheels
Testing Docol HE steel: a demanding fineblanking test
Watch our customer test Docol high edge ductility HSLA by fineblanking a “cogwheel” pattern with teeth having a 0.3mm radii and 30° angles.
Grades and mechanical properties
For best weight reduction, use higher grades with reduced thicknesses. All Docol HE grades are hot-rolled and meet EN10051 dimensional tolerances.
Looking for conventional automotive steels with tensile strengths from 550 MPa to 700 MPa in HSLA grades?
Forming high edge HSLA steel
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Excellent for fineblanking.
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30% better hole expansion ratios than conventional HSLA.
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Guaranteed bending radius of 0.0 xt.
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Enables crack-free forming operations along multiple, complex sheared stretched edges.
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Excellent for cold-forming of automotive components.
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Low alloy composition allows conventional welding and resistance spot welding.
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Reduced tool wear.
For specific forming guidance for your high edge ductility component, please contact our Technical Support.
Added benefits from Docol HE steel
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Good fatigue properties.
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Four grades: Docol 355HE, Docol 420HE, Docol 460HE, and Docol 500HE.
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Global availability and support.
OEM-specific high edge ductility HSLA
Docol 355HE, Docol 420HE, Docol 460HE, and Docol 500HE are made to SSAB specifications and can be dual certified with corresponding MC grades in EN 10149-2. In addition, we work closely with auto OEMs and Tier 1 suppliers to develop innovative, customized, high edge ductility steels for your specific components’ requirements.
High edge steel advantages for each team member
Safety engineers: Design crash-related safety components with stretched punched edges that are free of micro-cracks and subsequent part failure.
Production engineers: Reduce micro cracks, burrs, and other defects on complex sheared stretched edges. Leverage the higher hole expansion ratios of Docol HE HSLA/AHSS steels in new, demanding part designs.
Lightweighting engineers: Achieve thinner and lighter parts by specifying SSAB’s new, higher strength Docol HE AHSS grades.
Procurement officers: Buy less materials, as you greatly reduce the number of defective components with cracked sheared edges.
Sustainability officers: Due to the extreme efficiency of our steelmaking processes, Docol HE steels made from virgin iron ore have the same CO2 footprint as recycled steels. And SSAB Fossil-Free Docol steels will be available in 2026.
Reduce your CO2 footprint
Docol high edge ductility steel is “future proofed”.
TRIAL MATERIAL STOCK
HE steel samples
With our Trial Material Stock Center, you can get AHSS samples for most of our commercially available steels – as well as samples for our newest but not yet commercially released grades. Unique to the industry, we ship coils, sheets and custom lengths of any size. In 1 to 2 weeks, your material is ready for dispatch to anywhere in the world.
What is high edge ductility HSLA steel?
High edge ductility steels have a much finer microstructure and perlite distribution – achieved by using exceptionally clean and closely controlled steelmaking processes – than conventional HSLA Steels, providing increased formability, tight radii bending, and crack-free sheared cuts on stretched edges.
Why use high edge ductility HSLA steel?
Compared to conventional HSLA steels, high edge ductility steels have greatly improved local formability and high hole expansion ratios, helping you solve component defects like cracked outer edges and micro cracks on stretched punched holes.
Where is high edge ductility HSLA steel used?
High edge ductility steels are recommended as an alternative to corresponding HSLA grades when there is a need for improved edge ductility.
- Suspension systems
- Beams and cross members
- Wheels
- Chassis
What is the formability of high edge ductility HSLA steels?
- Ideal for fineblanking – opening up HSLA to new, complex designs and new component applications.
- Enables multiple, complex, crack-free forming operations along sheared stretched edges.
- Hole expansion ratios 30% better than conventional HSLA.
- Bend radius of 0.0 xt can be guaranteed.
FAQ
Other steel categories
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Ferritic-Bainitic steel: stretch edge flangeability for cold-forming
Ferritic-Bainitic are multi-phased steels with high hole expansion ratios and good edge stretch capabilities. FB steels are suited for cold-formed and punched flanges when lightweighting automotive components such as wheels, cross members, and other structural parts.
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High strength, low alloy (HSLA) steels for cost-effective automotive lightweighting
High strength, low alloy steels are a cost-effective choice for increasing strength-to-weight ratios when compared to conventional mild carbon steels. HSLA steels also have excellent bendability and weldability and can increase the strength and/or decrease the weight for a variety of body-in-white and chassis automotive components, including suspensions, beams, and subframes.
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Press hardening steels (PHS) for complex shapes
Press hardening steels have four major advantages: they can be formed into very complex shapes, their ultimate tensile strength ranges up to 2000 MPa (290 ksi), there is little or no springback, and, with tailored tempering, you can combine “full hard zones” and “soft zones” for multi-function crash performance within a single part.
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Complex phase (CP) steels for the highest hole expansion ratios
Complex phase steels have the highest — up to 100% — hole expansion ratios available from advanced high strength steels. Their high HER values provide excellent cold-forming properties for punched and stretched edges/flanges, as well as deep-drawn shapes. CP steels’ superior yield strengths are used for high crash-energy absorption, while their elevated UTS levels enable thinner walls for significant automobile weight reductions.
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Martensitic steel: excellent formability-to-strength ratio
Martensitic steel combines tensile strengths up to 1700 MPa with good ductility, making it highly efficient for both vehicle lightweighting and improved crash protection — especially in anti-intrusion zones.
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Dual phase (DP) steel: excellent ductility and energy absorption
Dual phase automotive steels have an excellent balance of ductility, high tensile strengths, easy cold formability, and very good crash energy-absorption. Its high early-stage strain hardening (n-value) makes DP steel resistant to local necking due to strain redistribution — providing highly uniform elongation. Dual phase steel’s low yield-to-tensile-strength ratio creates high global formability for deep-drawing and high-stretching capacities — all with good weldability.
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Dual phase with high formability/ductility for crack-free cold deep drawing
Dual phase with high formability/ductility (DH) steels are TRIP-assisted, 3rd Generation automotive steels with high global and local formability and good resistance to edge cracking. DH steel have excellent energy-absorbing properties, included reserved ductility during crash impact. DH grades are ideal for complex geometries, including cold deep drawing. DH steel's FLDs and HERs are superior to DP steels, enabling scrap reduction and more streamlined stamping.
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