STKO 50 – Alumino Silicate Sand (Grain)

STKO 50 is an alumino silicate, high-quality sand for precision investment casting use.

Designed for strength and thermal durability, STKO 50 features a coarser grain profile than STKO 22 or 35, with particles primarily in the U.S. #16 to #30 sieve range (approximately 600–1200 microns). This makes it ideal for backup slurry coats and stucco applications where high shell strength, increased permeability, and thermal shock resistance are essential. Its angular grain structure ensures strong slurry embedment and helps maintain consistent shell thickness, while low fines reduce the risk of surface defects. STKO 50 performs exceptionally in high-temperature pours and is compatible with both colloidal silica and ethyl silicate binder systems. Foundries casting aerospace alloys, stainless steel, or heavy industrial parts depend on STKO 50 to reinforce shell durability without compromising dimensional accuracy or finish.

Common uses include backup slurry layers, coarse stucco coatings, and builds where maximum structural integrity is required.

Ships in Bags. Larger orders available in Super Sacks.