EGBHZ Type Oil-Free Ejector Leader Bushings (SUJ2 Bearing Steel)

Leader-guided ejection systems in large mold and die casting tooling commonly use oil-free ejector leader bushings to maintain alignment without periodic lubrication. In automotive die-casting molds, they help stabilize centering during repetitive ejection cycles, minimizing galling risk and reducing maintenance downtime associated with oil management.

For appliance and consumer-goods injection molds where shop-floor oil control is critical, the oil-free leader bushing design supports consistent guidance while reducing lubricant contamination that can affect downstream finishing or assembly.

In long-cycle precision mold assemblies, the EGBHZ type configuration and SUJ2 bearing steel construction are suited for steady, low-maintenance operation where wear resistance is needed under sliding contact during ejector travel.

• Use when lubrication-free guidance is required for stable ejection alignment
• Select the correct inner diameter range (13–50 mm) and Dh6 section length (10–30 mm) for the leader interface

This variant is made from SUJ2 bearing steel, a common high-carbon chromium bearing grade used in precision sliding components. SUJ2 is selected for its balance of wear resistance and fatigue durability under cyclic contact typical of ejector guidance.

• Performance focus: high hardness after heat treatment to resist surface wear during repeated leader motion
• Toughness trade-off: harder martensitic structures improve wear life, but can reduce impact tolerance if overhardened

Heat-treated bearing steels like SUJ2 are typically supplied in a hardened and tempered condition for controlled hardness and dimensional stability. Exact HRC value is not specified in the provided data, so hardness targets should be confirmed against the supplier’s material certificate for your production run.

If alternative grades are considered, engineers usually choose higher wear grades for abrasive duty, while selecting tougher grades where shock loading dominates.

Start by matching the bushing’s inner diameter d (13–50 mm) to the leader shaft diameter in your ejector system. The leader must fit accurately through the bushing to ensure straight-line guidance through ejection travel.

• d (mm): choose within 13 ~ 50 to match the leader diameter
• ℓ (Dh6 section length) (mm): select from 10, 13, 15, 20, 25, 30 based on the required engagement length in the mold block

The notation ℓ (Dh6 section length) indicates a Dh6 section length reference; therefore, verify your leader/bushing interface drawings against the intended fit specification (e.g., clearance vs. near-interference) for stable guidance without excessive drag.

To select correctly, confirm: (1) leader shaft diameter (controls d), (2) required bushing working length along the leader axis (controls ℓ), and (3) available housing thickness and counterbore depth in the moving plate or die block.