Plungers
Plungers give machines a sense of position — the click of a detent, the hold of a spring-loaded ball, the lock of an index pin.
What are plungers?
A plunger is a spring-loaded pin or ball in a threaded or press-fit body. Ball and spring plungers create detents and hold parts against a stop; index plungers positively lock a moving element into indexed positions until manually retracted. They are standard elements in jigs, fixtures, guides and adjustable machine parts.
Types of plungers
Ball plungers
Spring-loaded ball in a threaded body — smooth detent action.
Spring plungers (pin type)
Flat or domed pin end for pressing and holding.
Index plungers
Retractable locking pin with knob — positive position locking.
Stopper / cushion types
Urethane-tipped and heavy-duty forms for end stops.
How to select plungers
- Thread size and body length for the mounting.
- Spring force class — light for detents, heavy for holding.
- End form: ball, pin, dome or urethane tip.
- Locking (index) vs non-locking action.
Not sure? Send what you have — a part number, drawing or photo — and our engineering team will confirm the selection.
Frequently asked questions
- What is the difference between a ball plunger and an index plunger?
- A ball plunger yields under side force — ideal for detents and temporary holds. An index plunger's pin positively locks into a hole and must be manually pulled to release — used where the position must not move under load.
Related components
Locating Pins
Locating pins fix a workpiece in a repeatable position on a jig or fixture. The round-plus-diamond pair is the standard method of constraining a part without over-constraint.
O-Rings & Seals
Every mould water line, cylinder and gearbox depends on seals. Standard O-ring sizes and the right elastomer keep them dry.
Shoulder Bolts & Stripper Bolts
A shoulder bolt is a bearing surface, a guide and a fastener in one part — and in press tools, the stripper bolt version carries the stripper plate itself.
Need plungers?
Tell us the specification, quantity and application — or just send the drawing.