What are the surface quality grades for DX51D coil?
A: They are graded as follows: FA (Standard), FB (Higher Grade), FC (High Grade), and FD (Extra High Grade Finish). Higher grades have stricter requirements for surface defects such as scratches and dents.
What are some common surface defects in DX51D coil?
A: Common defects include scratches, zinc particles, passivation spots, air knife marks, exposed steel, inclusions, embossing, roller marks, wavy edges, and warping.
How should passivation spots on DX51D coil be handled?
A: Minor passivation spots can be repaired by re-passivation treatment. For more severe cases, the defective area must be ground away before passivation treatment to avoid affecting subsequent coating results.
What are the thickness tolerance requirements for DX51D coil? A: The tolerance varies depending on the thickness. For example, the tolerance is ±0.06mm for 0.6-0.8mm, ±0.07mm for 0.8-1mm, and ±0.08mm for 1-1.2mm.
What are the typical width and length tolerances for DX51D rolls?
A: The width tolerance is generally within ±5mm, and the length tolerance is generally within ±10mm. Specific tolerances can be adjusted according to the agreement between the manufacturer and the customer.