Designing with G90 galvanized steel sheet metal
G90 galvanized steel is a go-to material when corrosion resistance and clean appearance need to work hand in hand. Coated with a layer of zinc for protection, it’s tough, formable, and ideal for enclosures, brackets, and structural parts that need to last. Below, we cover the most common questions about G90 steel and how to get reliable results when designing for SendCutSend’s laser cutting and forming services.
Key takeaways for G90 galvanized steel
- Zinc-coated for corrosion resistance: The “G90” designation means 0.90 oz of zinc coating per square foot of steel, providing long-term protection.
- Excellent formability: Can be bent, dimpled, or tapped without cracking or flaking the coating.
- Laser cut precision: Clean, burr-free cuts to ±.005″ tolerance across all available thicknesses.
- Strong yet workable: Combines the strength of mild steel with the added durability of galvanization.
- Multiple fabrication services available: SendCutSend offers bending, dimple forming, hardware insertion, and tapping for G90 parts.
What is G90 galvanized steel?
G90 steel is cold-rolled mild steel coated in zinc through the hot-dip galvanizing process. The zinc layer provides both barrier protection (sealing the steel from moisture) and cathodic protection (sacrificing itself to prevent rust if the coating is scratched). The “G90” rating indicates 0.90 ounces of zinc per square foot, offering one of the most durable galvanic coatings available for sheet applications.
What are the physical and mechanical properties of G90 steel?
G90 steel combines the base strength of mild steel with the surface protection of zinc. Typical properties:
- Density: 0.283 lb/in³ (7.83 g/cm³)
- Tensile strength: ~45–55 ksi
- Yield strength: ~30–40 ksi
- Elongation: ~20–25%
- Zinc coating weight: 0.90 oz/ft² (total both sides)
This makes it a smart pick for outdoor brackets, housings, and panels where raw steel would rust over time.
What is the difference between G60 and G90 galvanized steel?
The difference is in the zinc coating thickness.
- G60: 0.60 oz of zinc per square foot (lighter protection)
- G90: 0.90 oz per square foot (50% more zinc, longer lifespan)
If your part will face outdoor exposure, condensation, or humidity, G90 is the better choice. At this time, SendCutSend stocks G90 sheet metal but does not stock G60.
What are common applications for G90 steel?
G90’s strength and corrosion resistance make it a favorite for industrial and architectural uses. You’ll see it in:
- HVAC ducting and housings
- Electrical panels and enclosures
- Automotive brackets and body panels
- Appliance components
- Outdoor structural or decorative parts
Explore more options for your next project in our Material Catalog.
How does G90 perform during laser cutting?
SendCutSend laser cuts G90 with ±.005″ precision, achieving clean edges without damaging the zinc coating.
- Edge quality: Sharp and smooth, though the coating may slightly discolor along the cut edge.
- Heat-affected zone: Minimal; our high-powered lasers prevent coating burn-off.
- Post-cut finish: The zinc coating remains intact on most surfaces, maintaining corrosion resistance.
For detailed feature and hole sizing, check our Design Guidelines.
What tolerances and surface finish should be expected with G90 steel?
Laser cut G90 parts hold ±.005″ tolerances and ship with a clean, matte metallic finish.
- Surface appearance: Slightly spangled or mottled pattern from the zinc coating.
- Cut edges: Smooth and ready for assembly; light oxide may be present.
- Post-processing: Tumbling or light sanding can remove sharp edges if needed.
For dimensional and feature info, see the G90 steel specifications.
Can G90 steel be bent or formed?
Yes, G90 bends well with minimal risk of cracking or coating flake-off.
- Recommended inside bend radius: 1x material thickness or greater.
- The zinc coating may dull slightly at tight bends but remains protective.
- Proper tooling and clearance prevent surface marring.
SendCutSend offers bending on G90 Galvanized Steel. For precision bends, review our Bending Guidelines.
Can G90 be tapped or have hardware installed?
Yes, SendCutSend offers tapping, dimple forming, and PEM hardware insertion of G90 Galvanized Steel. This material takes threads and hardware inserts very well.
- Tapping works best in thicknesses above .060″ for thread depth.
- Hardware insertion (PEM-style fasteners) can be added cleanly through the zinc layer.
- Dimple forming improves thread strength and adds clearance in thin sheet.
Before adding additional services to your custom cut G90 parts, read our service guidelines.
Does welding affect G90 galvanized steel?
Welding G90 is possible but requires care. The zinc layer produces fumes when heated, so always weld with proper ventilation and respirator protection. After welding, grind or brush off the weld area and apply a cold galvanizing spray or zinc-rich primer to restore corrosion resistance. For most SendCutSend parts, we recommend fasteners or inserts as cleaner joining methods.
How durable is G90 over time?
The zinc coating provides long-term corrosion protection that can last decades depending on environment.
- Indoors or sheltered: 50+ years of protection.
- Moderate outdoor exposure: 15–25 years before visible wear.
- Coastal or high-humidity areas: performance depends on coating maintenance.
Periodic cleaning or touch-up extends its service life significantly.
Design tips for G90 sheet metal
Keep coating integrity and bend radius in mind when designing for galvanized steel.
- Avoid sharp inside corners or deep draw features that overstretch the zinc.
- Add bend reliefs where possible to prevent surface cracking.
- Plan hole sizes with clearance for hardware inserts or threads.
- Leave the zinc coating intact whenever possible for long-term rust protection.
For all design considerations, check our full Design Guidelines.
Why use G90 Galvanized Steel
G90 galvanized steel gives you the durability of steel with the rust protection of zinc — strong, affordable, and ready for long-term use. With SendCutSend’s laser cutting accuracy (±.005″) and available bending, dimple forming, hardware insertion, and tapping services, your G90 parts arrive ready to assemble and built to last. Compare G90 with other sheet steels and finishes in our Material Catalog.
