Heat Cast 40 Castable Refractory Cement – 40 lb Bag, 2,500°F, ASTM C-401 (Forge, Pizza Oven, Fireplace, Kiln)
Heat Cast 40 is a dense, pourable castable refractory cement that lets you form your own firebrick, hearth slab, forge lining or oven dome in any shape you need. Rated to 2,500°F and certified to ASTM C-401 Class B, it goes wherever firebrick is too rigid, too slow, or simply the wrong shape. Sold by the single 40 lb bag or by the 64-bag pallet, and ships free from our Midwest warehouse in 1–2 business days.
Cast the shape firebrick can't
Cut firebrick is fine for a straight wall. But a curved oven dome, a forge floor with a burner port, a replacement smoke-chamber slab, or a firebox with an odd angle needs a material you can pour. Heat Cast 40 mixes with plain water, pours or trowels into a simple form, and cures into a monolithic, crack-resistant refractory that stays non-water-soluble in service and holds up under repeated heating cycles. It's the same material masons and chimney pros have used for decades for custom hearths and firebox repairs.
Where it's used
- Forges and foundry furnaces – floors, burner ports, and full linings for propane and coal forges
- Wood-fired pizza and bread ovens – domes, hearth bases and entry arches
- Fireplaces and chimneys – firebox slabs, smoke chambers, cast-in-place replacement firebrick, hearth extensions
- Kilns – shelves, floor blocks and repair sections for pottery and glass kilns
- Wood stoves, boilers, masonry heaters – firebox liners and baffle plates
- Incinerators and crematoriums – heavy-duty cast sections and retort repairs
- Fire pits and outdoor fireplaces – cast liners and floor slabs that shrug off rain
⚠ Not rated for direct food contact – use firebrick for oven cooking surfaces.
Coverage: one 40 lb bag covers roughly 2 square feet at 2 inches thick. Not sure how many bags you need?
Call (800) 567-5358 or request a project quote and we'll size it for you.