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.

What is the definition of HSLA steel (high strength steel with low alloy)?

HSLA steels have yield strengths greater than 275 MPa (40 ksi) and are typically 20% to 30% lighter than carbon steel at the same strength levels. They are different than other advanced high strength steels (AHSS) as they are named after their yield strength.

HSLA is precipitation-strengthened ferrite and small amounts of pearlite and bainite. With little pearlite and no other hard phases, high strength steels with low alloy have better fineblanking properties than dual phase grades.

Low carbon and low (“lean”) alloy content also gives HSLA steels increased ductility, toughness, and weldability. Their low alloy content — plus no need for post-forming heat treatment — makes these high strength steels with low alloy an economical choice for many automotive body-in-white and chassis applications.

Steel properties

  • Higher strengths: from 420 MPa to 800 MPa yield strengths.
  • Good fatigue-loading performance: select higher yield strengths for durability-sensitive parts.
  • Improved formability, with excellent bendability for the rapid cold-forming of auto parts.
  • Weldability — HSLA’s lean composition readily lends itself to virtually all welding processes.
  • Greater inherent resistance to atmospheric corrosion than conventional carbon steels.
  • Economical lightweighting: a part’s strength can more than double, with a modest premium over using plain carbon steels.
  • Struggling with poor edge quality or having difficulty forming a part with crack-free edges? Our high edge (HE) HSLA steel can help.

Automotive applications for high strength, low alloy steels

HSLA steels provide a straightforward way to increase the strength of automotive components and thereby reduce their weight. Weldability is good due to lean alloy composition and bendability is excellent.

Hot-rolled Docol HSLA steels can be used for applications such as chassis, seat mechanisms, suspension systems and wheels.

Seat brackets and reinforcements can be suitable applications for cold-rolled Docol HSLA steels.

Either hot- or cold-rolled Docol HSLA can be used for beams and cross members, reinforcements, and other structural components.

Body in white

Grades and mechanical properties

Product Family

Docol 420LA

Product Family

Docol 500LA

Product name
Docol HR​500LA
Coating
UC
Dimensions
T: 2.00 - 6.00 mm
W: Up to 1600 mmT: 0.0787 - 0.236 in
W: Up to 62.99 in
Standards
VDA 239-100
Datasheet
Product Family

Docol 550LA

Product name
Docol HR​550LA
Coating
UC, GI*
Dimensions
T: 2.00 - 6.00 mm
W: Up to 1600 mmT: 0.0787 - 0.236 in
W: Up to 62.99 in
Standards
VDA 239-100
Datasheet
Product Family

Docol 600LA

Product name
Docol HR​600LA
Coating
UC
Dimensions
T: 2.00 - 6.00 mm
W: Up to 1600 mmT: 0.0787 - 0.236 in
W: Up to 62.99 in
Standards
SSAB
Datasheet
Product Family

Docol 650LA

Product name
Docol HR​650LA
Coating
UC
Dimensions
T: 2.000 - 6.00 mm
W: Up to 1600 mmT: 0.07874 - 0.236 in
W: Up to 62.99 in
Standards
SSAB
Datasheet
Product Family

Docol 700LA

Product name
Docol HR​700LA
Coating
UC, EG, GI*
Dimensions
T: 2.00 - 6.00 mm
W: Up to 1600 mmT: 0.0787 - 0.236 in
W: Up to 62.99 in
Standards
VDA 239-100
Datasheet
Product Family

Docol S900MC

Product name
Docol S900MC
Coating
-
Dimensions
T: 3.00 - 10.00 mmT: 0.118 - 0.3937 in
Standards
EN 10149-2
Datasheet
Product Family

Docol S960MC

Product name
Docol S960MC
Coating
-
Dimensions
T: 3.00 - 10.00 mmT: 0.118 - 0.3937 in
Standards
EN 10149-2
Datasheet
Product Family

Docol HR100XF

Product name
Docol HR100XF
Coating
UC
Dimensions
T: 2.00 - 10.00 mmT: 0.079 - 0.393 in
Standards
-
Datasheet
Product Family

Docol HR110XF

Product name
Docol HR110XF
Coating
UC
Dimensions
T: 2.00 - 10.00 mmT: 0.079 - 0.393 in
Standards
-
Datasheet

*Available upon request.

Corrosion-protected, metal-coated HSLA steels

  • GI hot-dipped galvanized coatings to EN 10346:2015 standards are available for corrosion protection on Docol® 420LA, 460LA, 500LA, 550LA and 700LA.
  • GA galvannealed coatings are available on Docol® 420LA, with test samples available for galvannealed grades-under-development: Docol® 460LA and 500LA.
  • ZA Galfan® coatings are available on Docol® 420LA, with test samples available for Galfan®-coated grades-under-development: Docol® 460LA and 500LA.

Forming high strength, low alloy grades

  • Ideal cold-working properties — and no need for post-forming heat treatments.
  • Optimized microstructure enables excellent bendability.
  • Improved fineblanking due to minimal pearlite and no other hard phases.
  • Excellent weldability.

Concerned about edge quality or micro-cracks during forming? Consider our high edge (HE) HSLA steel.

Roll forming Docol automotive steel

Extra benefits from Docol HSLA product line

  • Large selection of hot-rolled and cold-rolled HSLA steels, with eight basic (yield) strength levels: Docol® 420LA, 460LA, 500LA, 550LA, 600LA, 650LA, 700LA and 800LA.
  • Custom, OEM-specified HSLA grades allow for precise combinations of strength, formability, toughness, and weldability.
  • Good impact strength even at low temperatures.
  • Good fatigue strength: for example, for suspension arms, strut mounts, and other underbody components.
  • Good impact strength, e.g., for reinforcements, longitudinal beams, subframes, etc.

Are you looking for OEM-specific HSLA steel grades?

Docol® HSLA steel grades are supplied to EN 10149-2:2010 standards with dual certifications to the appropriate strength level MC standard also available. If you need an OEM customized HSLA grade, please contact our technical support for your specific automotive part application.

Custom AHSS for automotive OEMs

Where you benefit from Docol high strength, low alloy options

Safety engineers: Achieve optimized crash performance by selecting from a wide variety of HSLA strengths.

Lightweighting engineers: Accomplish straightforward weight reductions of 20% to 30% or more compared to typical carbon steels.

Production engineers: Use existing cold-forming equipment and techniques, ensuring rapid parts throughput with exceptionally consistent Docol® steel.

Buyers: Take advantage of Docol® HSLA steels affordability while more than doubling the yield strengths compared to your existing conventional carbon steel.

Sustainability officers: Immediately benefit from Docol® HSLA steels’ modest carbon footprint — getting virgin, iron-ore based grades with the CO2 equivalence of recycled steel. And in 2026, there will be fossil-free Docol® high strength steel with low alloy.

Future-proof you life cycle assessment

Removing CO2 from automotive steel

Docol® HSLA steel is “future proofed.”

coils

TRIAL MATERIAL STOCK

Get HSLA samples in multiple sizes

A unique offer from SSAB: we ship coils, sheets and custom lengths of any size, typically in 1 to 2 weeks. Get AHSS samples for both our commercially available steels, as well as our newest grades still in development.

FAQ

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