Guide Post and Bushing Fit — Clearance Basics

Mold guide posts and bushings rely on sliding fit without seizure over millions of cycles. **Common fit:** Post g6 (~0.01–0.03 mm clearance on Ø25) into bushing H7. Heavier molds or poor lubrication may need slightly more clearance — we follow your drawing callout. **Length and shoulder:** Post head height and bushing flange thickness must match plate stack. Mark shoulder lengths on section views, not only overall length. **Materials:** SUJ2 or 20Cr posts, nitrided for wear; bronze bushings for self-lube systems, hardened steel for press-fit into plates. **Inspection:** We check OD/ID and concentricity before shipment. If you specify fit class on the drawing, we hold it — otherwise confirm clearance on the RFQ. Custom lengths and oil groove patterns are standard at YZX Precision. Send plate stack section with post/bushing positions marked.