Q1Is the 355 in S355MC a yield figure or a tensile figure?
Yield. EN 10149-2 numbers the S…MC family on minimum yield strength ReH, so S355MC guarantees 355 MPa of yield and 430–550 MPa of tensile. This matters because the neighbouring families are not numbered the same way: JIS G3113 SAPH and the SPFH series are numbered on minimum tensile, so SAPH440 has a 440 MPa tensile requirement and a yield nearer 305 MPa. Comparing the digits alone will point you at the softer steel. Section 03 sets out the naming rules.
Q2S355MC or S355JR — they both say 355, so does it matter?
It matters a great deal if the part is formed. Both guarantee 355 MPa of minimum yield, which is exactly why drawings get them mixed up. S355JR is an EN 10025-2 structural grade with a higher carbon ceiling, a mandatory 27 J Charpy at +20 °C, and no guaranteed bend mandrel or cold-forming elongation. S355MC is an EN 10149-2 thermomechanical grade whose whole purpose is to guarantee both. If the part is pressed, drawn or roll formed, order the MC grade.
Q3Does EN 10149-2 give a Charpy impact value for S355MC?
Not as a default. The property table in EN 10149-2 fixes yield, tensile, elongation and the bend mandrel; impact energy is not one of the listed requirements, and mill data sheets list it as an option rather than a guarantee. If your part needs toughness at a given temperature, write the temperature and the required energy on the order as a supplementary requirement and we will confirm what the mill can certify at that thickness. Section 05 sets out what the standard does require.
Q4Can I substitute SAPH440, QStE380TM or StE355 for S355MC?
Only as an engineering decision, not as a paperwork one. QStE380TM and StE355 are the nearest yield-basis neighbours and are frequently quoted alongside this grade; SAPH440 is a tensile-basis designation with a materially lower yield and should not be substituted on the strength of its number. Each is a separate specification with its own chemistry limits, thickness steps and test directions, and a swap changes coating behaviour, welding procedure and fatigue performance. Section 07 lists them side by side — we will quote the original and the alternative together so you can compare both sets of figures.
Q5An earlier version of this page headed its property table S700MC — which is right?
The figures were right and the heading was wrong. The table published 355 MPa yield, 430–550 MPa tensile and 19 / 23 % elongation, which is the S355MC row; S700MC sits at the top of the same family at 700 MPa yield and 750–950 MPa tensile. We have corrected the heading here rather than changing it silently, so anyone arriving from an old search result or a cached page can see what changed. The full ladder is in section 05.
Q6Should I buy coil or cut sheet?
It depends on how the material enters your line. Coil is the natural choice for roll forming and for blanking presses fed from an uncoiler, and it is usually the cheaper form; sheet and cut plate suit presses loaded by hand, robot or stacker, and smaller batches. We supply either, with slit coil, decoiled and cut-to-length material, or blanks cut to drawing. Tell us the entry point rather than the form you think you need — coil ID, OD and weight are the details that most often decide it.
