Galvanized steel sheet for cable tray and electrical raceway is most often a choice between SGCC and DX51D. This guide explains how the two designations differ, where each is the right call, and how to specify the right sheet for bending, conductivity and corrosion performance.
Cable tray and electrical raceway systems are roll-formed from galvanized steel sheet, and the substrate choice drives both the forming behavior and the corrosion performance of the finished tray. SGCC is the JIS-standard continuous hot-dip galvanized sheet commonly supplied from Asian mills, while DX51D is the EN-standard designation widely used in Europe, the Middle East and Africa. The two are equivalent in most respects, but the call-out difference matters on international RFQs because the order will be matched against the mill's standard stock.
What SGCC and DX51D Mean for the Buyer
SGCC per JIS G3302 is a commercial-grade hot-dip galvanized sheet, with a typical zinc coating of Z06 (about 90 g/m² total both sides) to Z27 (275 g/m²). DX51D per EN 10346 is the European equivalent, with coating designations from Z100 to Z275 using the same g/m² convention. The substrate steel is mild steel with yield strength around 140–260 MPa, designed for cold forming. Both standards cover essentially the same product, so for export cable tray production, either call-out will be supplied against the mill's available stock and equivalent performance.
When SGCC Is the Right Call-Out
SGCC galvanized steel sheet is the right call-out for cable tray production in Asia and for export to markets that use JIS standards. Most Korean, Japanese and Chinese cable tray manufacturers stock SGCC in Z12 (120 g/m²) to Z18 (180 g/m²) coating, which is the practical default for indoor commercial and light industrial cable tray. The sheet has good formability for the deep draws and 90° bends typical of ladder-type and perforated tray, and the spangled surface is acceptable since most cable tray is hidden above ceiling or in risers.
When DX51D Is the Right Call-Out
DX51D galvanized steel sheet is the right call-out for cable tray production in Europe, the Middle East, Africa and South America. European tray manufacturers often run DX51D Z200 or Z275 for harsher environments, including outdoor tray runs, food plants and chemical facilities. The EN designation also makes it easier to match the tray to EN 61537 cable tray standards and to source matching accessories (fittings, covers, brackets) on the same supply chain.
Thickness, Coating and Forming Considerations
Cable tray sheet thickness is typically 1.0–2.0 mm depending on tray width and load class, with 1.2 mm and 1.5 mm being the most common stock sizes. For heavy-duty industrial tray (NEMA 20C or IEC 61537 class E), 2.0 mm substrate with Z275 coating is standard. The sheet must be ordered in the 01 or CQ (commercial quality) surface and A or B surface finish per the relevant standard, since extra-smooth or deep-drawing grades are unnecessary for most tray and increase cost. For bends and punched holes, specify that the coating adhesion be tested by 180° bend per ASTM A653, with no flaking.
What to Specify on the Cable Tray Sheet RFQ
State the standard (JIS G3302 SGCC or EN 10346 DX51D), the coating designation (Z12/Z18/Z27 or Z100/Z200/Z275), the thickness, the coil width, and the surface finish (regular spangle, passivated, oiled). For outdoor or corrosive environments, step up to Z275 / Z27 coating. Confirm that the mill test certificate includes the coating weight, the substrate chemistry, and the yield strength, since some mills will substitute a lower-grade substrate at the same price if the RFQ is ambiguous.
Related Resources from Baobin Steel
- Carbon steel sheet catalog – galvanized and cold rolled sheet
- Mild steel overview – grades and standards
- Request a quote – send your tray spec for galvanized sheet pricing