INDUSTRY COMPONENT

Plunger

A plunger is a precision cylindrical component in injection systems that creates pressure to force molten material into molds.

Component Specifications

Definition
The plunger is a critical component in injection molding and die-casting systems, typically a cylindrical rod that moves within a barrel or cylinder. It functions as a piston to generate hydraulic or mechanical pressure that pushes molten plastic, rubber, or metal through a nozzle into a mold cavity. Plungers are engineered for precise displacement control, pressure maintenance, and material flow regulation during injection cycles.
Working Principle
The plunger operates on hydraulic or mechanical pressure principles. During the injection phase, it moves forward within the barrel, compressing the molten material ahead of it. This creates high pressure that forces the material through the injection nozzle into the mold. The plunger's reciprocating motion is precisely controlled to manage injection speed, pressure profiles, and material dosage.
Materials
Typically made from hardened tool steels (H13, D2), stainless steels (420, 440C), or tungsten carbide for wear resistance. Surface treatments include nitriding, chrome plating, or PVD coatings to enhance durability and reduce friction.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Diameter20-150 mm
Stroke Length100-800 mm
Surface FinishRa 0.2-0.8 μm
Surface HardnessHRC 55-62
Operating Pressure100-200 MPa
Straightness Tolerance0.01-0.05 mm/m

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
ISO 10791-7, DIN 16760, ISO 12165

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Wear and scoring from abrasive materials
  • Seal failure leading to pressure loss
  • Misalignment causing binding or uneven wear
  • Thermal expansion affecting dimensional accuracy
FMEA Triads
Trigger: Abrasive material particles
Failure: Surface scoring and increased clearance
Mitigation: Use hardened materials with protective coatings, implement filtration systems
Trigger: Improper alignment during installation
Failure: Uneven wear and binding
Mitigation: Follow precise installation procedures, use alignment tools, regular inspection
Trigger: Inadequate lubrication
Failure: Increased friction and overheating
Mitigation: Implement automated lubrication systems, use high-temperature lubricants

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
±0.01 mm for diameter, ±0.02 mm for straightness
Test Method
Dimensional verification with CMM, surface roughness testing with profilometer, hardness testing with Rockwell scale

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Plunger

Manufacturer profiles associated with Plunger.

Sourcing Plunger from China?
Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.
Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Related Components

Sealant Layer
Sealant layer in multi-layer co-extruded barrier films for hermetic sealing and product protection.
Tie Layer
Tie layer is a bonding component in multi-layer co-extruded barrier films that ensures adhesion between incompatible polymer layers.
Mold Release Coating
Specialized coating applied to molds to facilitate easy release of silicone seal rings during manufacturing.
Silicone Polymer Base
Silicone polymer base is a high-temperature resistant polymer material used as the foundational component in silicone rubber compounds for industrial applications.

Frequently Asked Questions

What is the main function of a plunger in injection systems?

The plunger creates pressure to force molten material into molds during injection cycles, controlling material flow and dosage.

How often should plungers be inspected and maintained?

Plungers should be inspected every 500-1000 operating hours for wear, scoring, or surface damage, with preventive maintenance including cleaning and lubrication.

What materials are best for plungers in high-wear applications?

Hardened tool steels with surface treatments like nitriding or tungsten carbide coatings provide optimal wear resistance for demanding applications.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Request Manufacturing Insight for Plunger

Thank you. Your request has been sent. We'll respond within 1–3 business days.
Sorry, we couldn't send your message. Please try again, or email us at contact@cnfx.com.
Tie Layer
Get QuotesChat