Galvannealed Sheet & Coil Supplier
Paint that flakes off a finished panel sends parts back for rework and eats into the margin on the job. Every extra cleaning and prep step before the paint line slows production and adds labor to the job. Curtis Steel Company works as a galvannealed sheet & coil supplier for shops that want a paint-ready surface out of the bundle. Our galvannealed steel carries a matte zinc-iron finish that takes paint without mandatory pretreatment, and we stock it in Texas in coil and sheet form.
Galvannealed Steel Sheet That Takes Paint and Keeps It
Galvannealed steel, also called galvanneal, starts as carbon steel that runs through a continuous hot-dip line for a zinc coating on both sides.
As the strip exits the bath, an in-line heat treatment pulls iron from the steel into the molten zinc and converts the entire coating into a zinc-iron alloy.
The result is a non-spangled matte finish that looks nothing like the bright surface of galvanized steel and can pass for uncoated cold rolled steel at a glance. Shops that add a pretreatment step before painting get even longer paint life from galvannealed steel sheet.
How a Zinc-Iron Coating Gives Paint Something to Grip
The matte alloy surface gives paint more to bond with than smooth galvanized zinc, but it also behaves differently in the press. The coating on galvannealed steel coil and sheet is harder and more brittle, and it powders slightly during fabrication.
Heavier coatings powder more, so galvannealed coatings run thinner than most galvanized coatings. The thinner layer still provides long service life because the paint on top shields it.
Galvannealed performs best when you form the part first and paint it afterward, which the industry calls postpainting. Prepainting in coil form and forming the part afterward can crack the brittle coating and weaken corrosion protection once the part goes into service.
Galvannealed and Bonderized Steel Side by Side
Galvannealed and bonderized steel both start on a continuous hot-dip zinc line, and both give paint a surface to bond to. They differ in the surface treatment and in how each one holds up between delivery and the paint line. Curtis Steel stocks both in sheet and coil, so you can order the one that matches your finishing process.
| Galvannealed Steel | Bonderized Steel | |
|---|---|---|
| Specification | ASTM A653, CS-B, A60 coating | ASTM A653, CS-B, G90 coating |
| Coating | Zinc-iron alloy formed by in-line heat treatment | Galvanized zinc with a zinc phosphate treatment and dried-in-place chromate seal |
| Finish | Matte, non-spangled | Dull gray |
| Paint prep | No pretreatment needed before painting | Phosphate layer works as a built-in primer |
| Common uses | Automotive panels, garage doors, highway signs, computer chassis, and vending machines | Flashing, gutters, downspouts, roofing trim, signage, lighting housings |
Where Galvannealed Steel Goes to Work in Metal Buildings, Roofing, and Beyond
Painted galvannealed steel sheet holds up in parts that face weather, road salt, and years of daily use. Buyers put it to work in:
- Metal buildings: wall panels, roof panels, and trim
- Roofing: painted panels and trim components
- Automotive: exposed and unexposed body parts
- Buses and trucks: components on vehicles built for long service lives
- Commercial products: garage doors, highway signs, computer chassis, and vending machines
Galvannealed Steel Coil and Sheet Sizes Ready to Ship
Shops running their own slitting or blanking can order galvannealed steel coil in full widths, while fabricators who need flat stock can order galvannealed steel sheet cut to length. We process both in-house, so material arrives at the size your line or brake calls for.
- Specification: ASTM A653, Grade CS-B
- Coating: A60
- Treatment: CT-Dry
- Gauges: 10 GA through 26 GA
- Widths: 48" and 60"
Galvannealed Steel Size Chart
Product-Coated: Galvannealed | ASTM: A653 | Grade: CS-B | Coating: A60 | Surface: N/A | Treatment: CT-Dry
| Thickness | Width | Width | Width |
|---|---|---|---|
| 10GA (.1472 MAX - .1292 MIN) | *** | 48 | 60 |
| 11GA (.1323 MAX - .1143 MIN) | *** | 48 | 60 |
| 12GA (.1174 MAX - .0994 MIN) | *** | 48 | 60 |
| 13GA (.1014 MAX - .0854 MIN) | *** | 48 | 60 |
| 14GA (.0865 MAX - .0705 MIN) | *** | 48 | 60 |
| 16GA (.0696 MAX - .0575 MIN) | *** | 48 | 60 |
| 18GA (.0566 MAX - .0466 MIN) | *** | 48 | 60 |
| 20GA (.0506 MAX - .0356 MIN) | *** | 48 | 60 |
| 22GA (.0436 MAX - .0296 MIN) | *** | 48 | 60 |
| 24GA (.0316 MAX - .0236 MIN) | *** | 48 | 60 |
| 26GA (.0247 MAX - .0187 MIN) | *** | 48 | 60 |
Put a Galvannealed Sheet & Coil Supplier With Deep Texas Inventory on Your Next Order
A paint line only runs on schedule when the steel shows up ready to paint. Tell us the gauge, width, and quantity you need, in coil or cut sheet, and our team will quote it from the inventory we keep in Houston, Dallas-Fort Worth, and Harlingen. If you're moving painted work over from bonderized, our sales team can walk you through the switch before your first order ships.
Request a quote today, and work with a galvannealed sheet & coil supplier that has kept fabricators, builders, and roofers stocked since 1976. Give us a call at 1-800-749-4621 or contact us online.