Uniflasy Cast-Iron Grill Grates for Weber Spirit & Genesis, 17.5 x 11.9 in Pair — Heavy-Duty Searing, Heat Retention

Uniflasy cast-iron replacement grates (17.5 x 11.9 in each) are a heavy-duty, high-heat upgrade designed to fit many Weber Spirit 300/700 and Genesis 1000–3500 gas grills.

These replacement grates from Uniflasy are engineered to match the footprint and mounting points of numerous Weber Spirit and older Genesis models so you can restore or improve your grill’s searing performance without replacing the entire cooking system. Forged from solid cast iron, they prioritize heat retention and defined sear marks, while sized pairs combine to cover the standard two-burner area found on many 3-burner Spirit and Genesis barbecues.

Which grill models do these grates fit?

They are made to replace original grates on a wide range of Weber Spirit models (300 series, Spirit 700, and Spirit II variants such as E-310/S-310) and many older Genesis lines including Genesis Gold/Silver B & C and Genesis 1000–3500 series. They do not fit Genesis Silver A or some newer Genesis II LX variants.

• Compatible with Spirit E310/S310, E315/S315, E320/E330, and Spirit 700.
• Work with Spirit II GS4-equipped 300-series grills (E-310/S-310/SP-310/SP-330).
• Fit many Genesis Gold & Silver B/C models (2000s–2010s) and 1000–3500 series.

How do cast-iron grates change cooking performance?

Cast iron holds and spreads heat more uniformly than thin steel, producing stronger sear marks and a more consistent grilling surface for steaks, chops and vegetables. That extra thermal mass also helps maintain stable temperatures when you open the lid for turning or basting.

• Superior heat retention for even cooking and better searing.
• Creates pronounced grill marks that enhance flavor perception.
• Recommended for frequent high-heat grilling and sear-focused cooking.

What are the material and size details I should know?

Each grate measures 17.5 by 11.9 inches; two pieces pair to cover a typical 3-burner Spirit/Genesis cooking area of about 17.5 x 23.8 inches. They are cast from solid iron rather than enamel-coated steel, giving them durability and improved thermal performance, though they do require seasonal care to protect against corrosion.

• Individual grate: 17.5" x 11.9"; full set: 17.5" x 23.8".
• Solid cast-iron construction for long-term heat stability.
• Not enamel coated — benefits searing but needs seasoning and maintenance.

How difficult is installation and upkeep?

Installation is straightforward: the grates drop into the existing support ledges and align with standard Weber mounting positions for compatible models. Regular seasoning and drying after cleaning will keep the cast iron performing well; avoid long exposure to moisture to reduce rust risk.

• Tool-free drop-in installation for compatible Spirit/Genesis models.
• Season before first use and after heavy cleaning for a nonstick surface.
• Hand-clean with a brush; dry and lightly oil to protect between uses.

Who is this set best for? These Uniflasy cast-iron grates suit home grillers who own compatible Weber Spirit or older Genesis models and want stronger searing, improved heat stability, and a durable cooking surface without replacing the whole grill. Choose these grates if you frequently cook at high temperatures, prefer clearly defined grill marks, or need a direct-fit, heavy-duty replacement for worn or damaged original grates. If you need stainless-steel alternatives or have a newer Genesis II LX model, check model fit carefully before buying.