Purlin 1, Standard: 41x41, 41X21 2, Wall thickness: 1.5~2.8mm 3, Length: 3m, 5.8m, 6m 4, Treatment: HDG, PG Purlin 1, Standard: 41x41, 41X21 2, Wall thickness:1.5mm, 1.6mm, 2.0mm, 2.5mm, 2.7mm 3, Length: 10', 20' (3m, 5.8m, 6m) or required by the clients 4, Type: slotted and plain with any color (yellow, white etc.), single & back to back 5, Treatment: hot dip galvanized, pre-galvanized ...