Sprue Bushes

Overview

Sprue bushings (or sprue bushes) serve as the essential bridge between the injection machine nozzle and the mold cavity. Made of hardened steel or high-performance alloys, they guide and seal the flow of molten material—plastic in injection molding or metal in die casting—ensuring controlled, consistent delivery and protecting the mold components.

Sprue Bushes

Key Features

High-Durability Materials
Crafted from tool steels (e.g., SKD61, H13) or copper-based alloys, often with carbide linings, sprue bushes withstand heat, pressure, abrasion, and corrosion.
Flow Management and Leak Prevention
These components direct molten material precisely while maintaining tight sealing at the nozzle interface—minimizing material leakage and ensuring smooth mold filling.
Temperature Control (Hot vs Cold Types)
- Cold sprue bushes are unheated and may require sprue removal post-molding.
- Hot sprue bushes include built-in heating elements to keep material molten and reduce solidification/blockage.
Enhanced Cycle Efficiency
Sprue bushes help form rigid sprues that cool efficiently—key for automated removal tooling and reducing cycle times.
Precision Fit & Alignment
Accurate dimensions—including inlet aperture and nozzle radius—ensure a precise fit with the machine nozzle, preventing air entry or material flash.
Ease of Replacement & Mold Maintenance
Designed for easy replacement during mold servicing, sprue bushes protect the mold from wear and simplify maintenance.
Advanced Thermal Designs (Conformal Cooling)
Cutting-edge models offer conformal cooling channels that better regulate temperature, reduce cycle time, and extend service life—especially useful in high-speed or complex molding setups.