According with the standard: EN 10305-2;

Steel grade: E355;

Delivery condition: +C;

ID tolerance range: according with ISO H;

Roughness on the ID: Ra < 0.8 µm

Mechanical properties: Rm > 640 N/mm2 ; Rs > 512 N/mm2; Ap5 > 4%;

Tests: visual, dimensional, mechanical test and chemical analysis, ultrasound check 100%.