+0.005mm S136 (AISI 420) Ejector Sleeves | Mirror Polished Mold Bushings

Product Overview

S136 (AISI 420) Precision Ejector Sleeves are critical functional components used in plastic injection moulds to ensure stable ejection and long service life. Manufactured by Senlan Precision through CNC machining and precision grinding, these custom ejector sleeves offer excellent corrosion resistance, dimensional stability, and wear performance for high-cycle mould applications, including medical and packaging moulds.

Core Features & Technical Advantages

• Material: S136 / AISI 420 Stainless Mold Steel
  High corrosion resistance, suitable for humid, medical, and clean molding environments

• High Dimensional Accuracy
  Internal and external concentricity controlled to tight tolerances (≤ ±0.01 mm upon request)

• Optimized Surface Finish
  Precision grinding and honing to reduce friction and ejector wear

• Stable Heat Treatment
  Uniform hardness distribution to maintain straightness and service life

• Custom / Built-to-Print Manufacturing
  Diameter, length, wall thickness, and clearance produced strictly per drawing

Application Scenarios / Industry Use

• Plastic Injection Moulding Systems

• Bottle Cap Moulds and Closure Moulds

• Medical Packaging and Disposable Medical Moulds

• Syringe and Medical Consumables Moulds

• High-Cavity Packaging Moulds

Designed for moulds requiring reliable ejection, corrosion resistance, and long production cycles.

Mould Structure & Design Explanation

Ejector sleeves are typically used together with ejector pins, core pins, or valve pin systems to guide and protect internal moving components during part ejection.
In high-precision mould structures, S136 ejector sleeves help maintain:

• Accurate axial alignment

• Controlled clearance between pin and sleeve

• Reduced galling and seizure risk

• Stable ejection under high cycle conditions

Proper sleeve design directly affects mould lifespan and part consistency.

Manufacturing Capability & CNC Machining Process

Senlan Precision produces ejector sleeves using a controlled, multi-stage process:

• CNC Turning & Milling for external geometry

• Deep Hole Machining / Honing for internal bore accuracy

• Precision Grinding for OD/ID concentricity

• Heat Treatment Control to minimize distortion

• Final Inspection using bore gauges, CMM, and concentricity measurement

Typical tolerance capability: ±0.005 – ±0.01 mm, depending on design requirements.

Custom Development & OEM Cooperation Process

1. Drawing Review (Built-to-Print)
   2D/3D drawings or samples accepted

2. Technical Confirmation
   Material, hardness, clearance, surface finish, and tolerance definition

3. Prototype or Direct Production
   Small batch or mass production support

4. Final Inspection & Approval
   Dimensional and functional verification before shipment

5. Long-Term Supply Support
   Stable repeatability for ongoing mould maintenance programs

Quality Control & Export Experience

• ISO 9001 quality management system

• Incoming material traceability

• In-process dimensional control

• 100% inspection on critical dimensions

• Extensive export experience for mould components used in packaging and medical industries

Documentation and inspection reports can be provided upon request.

Related Precision Mold Components (Internal Links)

• Precision Ejector Pins

• Custom Core Pins

• Mold Inserts and Cavity Components

• Guide Pins & Guide Bushings

• High-Precision Injection Mold Components

Frequently Asked Questions (FAQ)

Q1: Why choose S136 (AISI 420) for ejector sleeves?
A: S136 offers excellent corrosion resistance and polishability, making it suitable for medical and packaging mould environments with strict cleanliness requirements.

Q2: Can you control internal bore concentricity?
A: Yes. Internal bore and OD concentricity can be controlled within tight tolerances using honing and precision grinding.

Q3: Do you manufacture non-standard ejector sleeves?
A: Yes. All ejector sleeves are produced as custom, built-to-print components based on customer drawings.

Q4: What is the typical lead time?
A: Sample lead time is typically 7–15 working days, depending on complexity and quantity.

Get a Technical Quotation

For custom S136 ejector sleeves, detailed drawings, or OEM cooperation, please contact Senlan Precision.
Our engineering team will review your requirements and provide a technical quotation based on material, tolerance, and application needs.