Class C Galvanized Steel Strand 1x19 8-16mm Extra Heavy Zinc Coating for Coastal Guy Lines

Class C galvanized steel strand, 1x19, 8mm to 16mm, with an extra heavy zinc coating for guy lines that live in salt air.

Coating class is the cheapest insurance on a galvanized strand and the first thing a cost driven buyer removes. Class A coating gives roughly 215 to 260 grams of zinc per square metre and is fine inland. In a coastal yard that same strand will show red rust at the low points within a few years, long before the steel has lost any meaningful strength.

Class C coating puts roughly 460 to 550 grams per square metre on the wire, more than double. That is not a marketing figure, it is measured by stripping the coating from a known length and weighing it. The trade off is a slightly larger overall diameter for the same wire size and a coarser surface that grips clamps a little harder, which in guy work is an advantage rather than a problem.

• More than double the zinc of Class A: Between 460 and 550 grams per square metre against 215 to 260 for a standard coating. In a salt spray chamber the difference is not linear, it is the difference between first rust at 200 hours and first rust beyond 1000 hours.
• Sacrificial protection after a scratch: Thick zinc keeps protecting the steel at a mechanical damage point until the zinc around that point has been consumed. Thin coatings fail at the first deep scratch, which is why handling damage matters so much more on Class A strand.
• 1x19 for stiffness and clamp grip: Nineteen wires give a round, firm strand that holds its shape in a guy clamp and does not flatten under bolt torque. It also resists the vibration that loosens fittings on long guy runs.
• Sized for real guy loads: From 8mm for pole guys through to 16mm for mast and tower work. Common sizes are held in stock in 1m increments so a short order does not wait for a production slot.
• High carbon wire underneath: Grade 60# and 70# wire gives the strength, the zinc gives the life. We never compensate for a thin coating by using a higher strength wire, because corrosion is the failure mode in coastal work, not overload.
• Terminology kept honest: Class C per ASTM A475 is quoted with the actual measured coating mass on the certificate. If a supplier cannot show the stripped weight for your lot, the class on the label means very little.

Typical work is pole and tower guy lines within a few kilometres of the sea, guy sets on communication masts, and anchor strand on marine structures such as jetty canopies and fender systems. It is also used for overhead static wire in coastal substations.

Inland, buyers choose Class C where a guy cannot be re-tensioned or replaced easily: remote sites, mountain tops, and installations where the access cost of one maintenance visit exceeds the price difference of the entire reel.

• Coastal pole, tower and mast guy lines
• Marine structure anchor and stay strand
• Coastal substation static wire
• Remote site guys where access is expensive
• Long life outdoor tensioning and bracing

Coating mass is measured by the stripped weight method on both ends of each lot and recorded on the certificate. We also run a salt spray test to ASTM B117 on a sample per month, with first red rust time logged and trended so a change in the galvanizing line shows up before the customer sees it.

Breaking load, elongation and torsion are tested per lot. Strand is inspected for exposed steel at wire crossover points, because a coating that is thick on the outside and thin where wires touch is a common defect of poorly set up galvanizing lines.

Iron or heavy wooden reels of 500m to 2000m, VCI wrapped, strapped and marked with size, length, coating class, measured zinc mass and lot number. For small guy sets we cut and coil to length with both ends served, so the crew does not cut a 2000m reel for four short guys.