HIGH STRENGTH STEEL


Domex and Supraform


High strength steels are steel which can be attained in various types, all which has a guaranteed value for yield strength as well as tensile strength.

Two of the main high strength steels available in South Africa are Domex and Supraform. Supraform is manufactured by Arcelor Mittal while the Domex range is manufactured by SSAB.  

Both these high strength steels provide the end user, or the manufacturer of cold formed sections with steel that is weld able and improved toughness. Both these high strength steels are available from a 2mm minimum wall thickness. Supraform steel is available up to a 10mm while the Domex range is supplied up to 12mm wall thickness, depending on the strength of the material required.

The high strength steels are similar in comparison as is indicated in the table below: 

SSAB 

Arcelor Mittal Range

 Product Name

Yield Strength 

 Product Name

 Yield Strength

 DOMEX 315 MC

315 

TM 340

340-420 

 DOMEX 420 MC

420 

TM 380

380-460

 DOMEX 460 MC

460 

TM 420

420-500

 DOMEX 500 MC

500 

TM 460

460-560 

 DOMEX 550 MC

550 

TM 600

600 

 DOMEX 600 MC

600 

 

 

 DOMEX 650 MC

650 

 

 

 DOMEX 700 MC

700 

 

 


One of the key factors for a steel tube or profile manufacturer when cold forming with high strength steel is to calculate the amount of spring-back that the material will have while being formed. As Domex and Supraform is a lot stronger than the normal steel in the market, such as S355 High Tensile, it has a wider spring-back range that should be accounted for. A potential way of countering the spring back when cold forming high strength steel as an open profile is to over form the material, then under form the material and in the last pass to re-form the material to the desired angle.

Tubecon have in the past cold formed open sections including lip channels and U-channels from Domex 700 as well as TM600 while rolling steel tubes and other welded sections from Domex 450.