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.
Pin Plungers
Plungers with a movable pin at the tip.
They offer a longer stroke than ball plungers.
Accessories
Wrenches for Pin Plungers
These dedicated wrenches are for mounting and removing short-stroke plungers
（PSP、
PSP-N、
PSPS、
PSPS-N）
and long-stroke plungers
（PLP）from the pin side.
Plunger Holders
Holders for mounting plungers.
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.
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.
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
