Second record from the same month: DIN 2391 precision tube in St35, condition NBK, 6 × 2 mm, 5,800 mm lengths, packed into a single 20 ft container for a customer in Indonesia in October 2026.
What went into the container
| Outside diameter | Wall | Length |
|---|---|---|
| 6 mm | 2.0 mm | 5800 mm |
One position only. Single-size loads are the easier ones to pack — no mixed bundle to sort at destination — but 5,800 mm is a non-standard length, so the cutting plan has to be set before drawing rather than trimmed afterwards.
Standard, grade and condition
Produced to DIN 2391, the German standard for seamless cold-drawn precision steel tube, in steel St35. St35 is the older designation; the current European equivalent is E235 to EN 10305-1, and drawings with either marking can be quoted the same way.
Delivery condition NBK — cold drawn and then normalised. The difference from BK matters more than the price difference:
- BK – cold drawn, not heat treated. Hardest and strongest, but the bore distorts slightly and the tube springs back when bent.
- BKW / BKS – annealed or stress relieved. Softer, easier to machine, dimensions stable.
- NBK – normalised after drawing. Uniform grain structure across the wall, predictable behaviour under bending and machining, and the closest thing to a clean starting condition for a part that will be cut, turned or welded.
Where a drawing says only “DIN 2391 St35” and nothing about condition, we ask before producing. BK and NBK are not interchangeable in a machining process, and the difference only shows up after the first batch is scrapped.
Packing
- Bundles wrapped in plastic film, strapped with steel band
- Ends protected against handling damage in transit
- Timber dunnage between layers and against the container walls
- No crate for this order — single size, uniform bundle length
A 20 ft container is worth checking against the order weight before packing starts: the door in the photograph reads 28,295 kg payload. Precision tube is dense, so a full container of small diameter is often limited by weight rather than by volume.
Documents
- Inspection certificate 3.1 — heat analysis and mechanical properties
- Packing list with bundle numbers, size and quantity
- Commercial invoice and certificate of origin
- Third-party inspection before loading, on request