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Date Updated:Apr. 30. 2025

Description of Plungers for Engineers

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What are plungers?

Plungers are mechanical components used for positioning and securing workpieces.
A spring is built into the main body. This spring allows the ball or pin at the tip to retract when a load is applied, and it returns to its original position by spring force when the load is removed.

Types and Features of Plungers

We offer a wide range of plungers in various sizes, materials, and spring loads to meet your specific needs.

Ball Plungers

Plungers with a movable ball at the tip.
They are suited for sliding mechanism positioning because the ball retracts under both vertical and lateral loads.

List of Ball Plungers

Pin Plungers

Plungers with a movable pin at the tip.
They offer a longer stroke than ball plungers.

List of Pin Plungers

Accessories

Wrenches for Pin Plungers

These dedicated wrenches are for mounting and removing short-stroke plungers (PSPPSP-NPSPSPSPS-N
and long-stroke plungers (PLP)from the pin side.

>>Wrench for Pin Plunger PPW

Plunger Holders

Holders for mounting plungers.

>>Plunger Holder PHL

Product Finder

Our efficient "Product Finder" allows you to quickly find your desired products.

Advantages of Using Plungers

The spring-loaded reciprocating mechanism of the ball or pin can be easily integrated into devices and equipment.


Example: Pin Plungers

Without a plunger: Each part, including the pin, spring, and spring holder, must be designed separately.

With a plunger: Simply mount the plunger.

Examples of Plunger Applications

Die Positioning

Workpiece Ejection

Drilled Hole Positioning Jigs

Limit Switches

Relief Valves

Plunger Load and Stroke

  • Min. Load (Initial Load): The load at which the plunger ball or pin begins to retract.
  • Max. Load: The load at which the plunger ball or pin is fully retracted.
  • Stroke: The distance the ball or pin can retract into the main body.
  • The plunger load varies linearly between the Min. Load and Max. Load.
    The plunger spring constant K can be calculated in the following formula:
  • The load F1 at which the ball or pin retracts a distance S1 can be calculated using the following formula:

 

Additional Services

Vibration Resistance

We offer anti-loosening treatments for screws.The treatment is ideal for applications requiring secure screw fastening or sealing, eliminating the need for additional adhesives or sealing tape.

Click here for details >

Cleanroom Services

We offer cleanroom washing and packing services, ideal for components used in flat panel display and semiconductor production equipment, medical devices, and food-and-beverage machinery.

Click here for details >

Special Products

We design and manufacture plungers with optimal specifications for various operating conditions, including shape, dimensions, load, and material.
Please specify the following conditions when contacting us:

  • Type: Ball type or pin type (for ball types, please indicate if a spacer is used)
  • Shape/Dimensions: Thread nominal diameter, screw pitch, thread length, ball or pin diameter, stroke, and overall length
  • Load: Min. Load (initial load)/Max. Load
  • Material/Finish: Main body, ball or pin, spring
  • Vibration Resistance: Required / Not required
  • Operating Conditions: Temperature, atmosphere, service life, etc.



Description of Mechanical Components for Engineers

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