Coil is a steel or iron plate of fixed thickness produced through hot or cold rolling. Its structure consists of a surface layer, a hard middle layer, and a soft inner layer. Common materials include: 1. Ordinary carbon steel coil (carbon content 0.05-0.25%), which offers excellent weldability and cold formability (elongation ≥30%) and is suitable for furniture and automotive manufacturing, but also has a relatively high magnetic permeability (>5000μ); 2. Low-}alloy hai-strongpela koil (yield strong 355{{6}690 MPa), we i givim moa long 50% impruv weta resistens na ol i wokim stret bilong lod-i karim ol straksa olsem ol bris na sip; 3. Hae-} strong stiel plet (tensael paoa Bigfala bitim o i sem mak long 780 MPa), we oli yusum fastaem long transit mo aviesen blong rel, be i nidim hae-tempereja tritmen antap long 1000 digri blong fom; 4. Steinles stiel koil (kromium konten Bikpela moa long o wankain olsem 10.5%), we i no inap long asid na alkali korosen (long olgeta yia korosen reit<0.01mm), is a preferred material for food processing equipment.