STKO 33 – Alumino Silicate Sand (Grain)

STKO 35 is an alumino silicate, high-quality sand for precision investment casting use.

Engineered to deliver strong refractoriness and reliable thermal stability, STKO 35 is part of the trusted STKO line of alumino silicate grains. Slightly coarser than STKO 22, it features a grain profile primarily above U.S. #30 sieve (roughly 400–800 microns), making it ideal for backup coats where shell strength and permeability are key. The clean, angular grains promote excellent slurry adhesion and reduce dust and fines that can compromise shell integrity. Compatible with both colloidal silica and ethyl silicate binders, STKO 35 helps create ceramic shells that hold up under high-temperature pours, autoclaving, and handling. Foundries casting aerospace components, stainless steels, and other complex alloys trust STKO 35 to provide the backbone of the shell structure while maintaining casting precision and consistency.

Common uses include backup slurry layers, ceramic shell reinforcement, and applications requiring strong dimensional stability and high heat resistance.

Ships in Bags. Larger orders available in Super Sacks.