{"id":7748,"date":"2026-09-17T08:08:51","date_gmt":"2026-09-17T08:08:51","guid":{"rendered":"https:\/\/chinametalfoundry.com\/?p=7748"},"modified":"2026-09-21T08:24:51","modified_gmt":"2026-09-21T08:24:51","slug":"casting-mold-design-patterns","status":"publish","type":"post","link":"https:\/\/chinametalfoundry.com\/de\/blog\/casting-mold-design-patterns\/","title":{"rendered":"Mold & Pattern Design for Castings: Draft, Shrinkage, Cores"},"content":{"rendered":"

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Most casting quotes fail long before metal is poured. They fail in casting mold design<\/strong> \u2014 the week of decisions about draft, parting line, shrink rule and core prints that quietly locks in your scrap rate, your machining bill and your tooling budget for the next five years.<\/p>\n<\/div>\n

This is a shop-floor guide to those decisions. Every number here is one we actually use: draft angles by process, the patternmaker’s shrink rule in both imperial and metric, the buoyancy math that decides whether a core floats, and the four-gate review we run before any pattern gets cut. Where the industry has a written standard, we cite it \u2014 the American Foundry Society (AFS)<\/a> for sand practice and NADCA<\/a> for die casting. Everything else comes from our own production records across Sandguss<\/a>, Feinguss<\/a> and die casting programs.<\/p>\n

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A pattern is not a drawing of the part \u2014 it is the part plus draft, plus shrink, plus the geometry the mold needs to release it.<\/figcaption><\/figure>\n

What Casting Mold Design Actually Controls<\/h2>\n

Tooling is usually 5\u201315% of a program’s total spend, but the geometry it encodes drives 60\u201380% of downstream cost. That is the asymmetry buyers miss when they shop a pattern quote on price alone. Four variables do most of the work:<\/p>\n