DIN2391 ST37.4, ST52.4 bright annealed and bright normalized seamless cold drawn steel tube
Process:
Cold drawn, seamless tube
Steel grades:
ST37.4 (E235N)
ST52.4 (E355N)
Dimensional range:
Outside diameter: 4-30mm
Wall thickness: 0.5-10mm
Length: standard 6000mm or on request
- If one of the limit deviations for the diameter is to be zero, the limit deviation for the wall thickness shall be equal to 10% of the mean wall thickness calculated using the formula given in clause 2 of DIN2391 Part 1.
Delivery condition:
BK, BKW, BKS, GBK, NBK
Appearance:
- Tubes have a smooth internal and external surface
- Surface imperfections such as scabs or gouges resulting from the manufacturing process, are not permitted provided the inner and outer diameters. Laps and laminations are also not permitted.
Test and inspection:
- Eddy current test
- Ultrasonic test
- Hardness
- Flattening, as specified in DIN EN 10233
- Flaring
- Bending
- Chemical composition analysis
- Mechanical properties (tensile, yield, elongation), as specified in DIN EN 10002 Part 1
- Metallographic analysis
In compliance with commercial practice, the tubes shall be supplied with provisional corrosion protection:
- Coated oil
- Black phosphated
- Zinc coated
Straightness:
- Tubes with an outside diameter exceeding 15mm shall not deviate from straightness by more than 0.25% oft he total length
- Tubes with a yield strength greater than 500N/mm2 shall be deviate from straightness by more than 0.3% of the total length
- Localized deviations shall not exceed 3mm/m and shall be measured as the distance between the tube surface and a chord linking two random points 1000mm apart
Packing:
Wooden case
