Incoming coil inspection and storage: what we check before processing
Every coil that enters our plant is checked against its certificate, identified and stored so that its data can be traced to the finished part.
Most processing problems that customers notice—a wrong width, a damaged edge, a lamination with higher loss than expected—can be prevented at the moment a coil arrives. That is why incoming inspection is the first step of every order at our processing base, before a single cut is made.
1. Documents first
Before unloading, the delivery documents are compared with the purchase order: grade, nominal thickness, width, coil weight and coil number. The mill certificate for each lot is filed with the coil number. For Baosteel GO material we check that the certified P1.7/50 core loss and B8 values meet the guaranteed values of the ordered grade.
2. Visual and dimensional checks
- Packaging intact, no water marks, no rust on the outer wraps.
- Edges free of dents and telescoping that would make slitting difficult.
- Width within tolerance; for Baosteel GO the width tolerance is 0/+2 mm.
- Thickness measured at several points across the width against the ±0.02 mm (0.23 mm) or ±0.03 mm (0.27–0.35 mm) tolerance.
- Coil inner diameter 508 mm as ordered.
3. Identification and traceability
Each master coil receives an internal label that links the mill coil number to our job number. When the coil is slit, every daughter coil inherits that link, and the same applies when strip is cut into laminations or stacked into cores. If a customer asks which mill lot a core came from, we can answer from the records.
4. Storage conditions
Electrical steel is sensitive to moisture and to mechanical damage. Coils are stored indoors on saddles or pallets, off the floor, away from doors and washing areas, and handled with C-hooks or padded lifting equipment so that the edges and the insulation coating are not damaged. Opened coils are re-wrapped at the end of each shift.
These steps take little time compared with processing, but they protect the properties you paid for. If you need specific inspection records with your delivery, tell us when you place the order.
