Technical reference
Casting data sheet for design engineers
Standard linear tolerances, surface finish expectations and design rules for silicon-sol investment castings. Use these benchmarks to check feasibility before you send a drawing for review.
Dimensional benchmarks
Linear, flatness and angularity
Linear dimensions
General investment casting linear tolerances conform to standard industrial investment casting classes. Confirm the applicable class against your drawing before release.
Flatness
Flatness depends on section size, wall thickness and geometry. Call out critical flat faces on the drawing so they can be reviewed during feasibility.
Angularity
Angular tolerances follow the feature size and casting orientation. Mark datum references clearly so angle requirements can be checked against the pattern.
Surface finish
Surface roughness and design rules
Surface finish capability regularly achieves clean Ra 3.2 to 6.3 micrometers as-cast. Holes, radii and draft angles should be defined early so the mold can be filled cleanly and maintained over its life.
Draft angle and minimum wall thickness criteria balance flowability and mold filling. Share your drawing so the wall and draft requirements can be reviewed before tooling begins.
Design checklist
Specify the surface roughness target, the minimum hole diameter and depth, the fillet radius at internal corners, and the draft angle on vertical faces.