Small Indexing Plunger with Circle Clamping Knob, M8 x 1.0 x 20mm, D21, pin4
PSK300-2108200406
Spring loaded pull pin, Indexing plunger, Pop pin
For mini machinery using screws or knobs, precise locking and appealing design matter. UJEN’s compact plungers cover M8–M16, with 4–10mm pin specs. This knob includes a ring and four shape variations, plus 7 color discs/rings for customization. Taiwan CNC and mold manufacturing guarantee accurate tolerances and durability, with wood fiber or oyster shell plastic for eco aims. ISO9001-compliant, we handle high-volume or bespoke B2B orders in medical, automotive, sports, and semiconductor fields.
Function
Small spring pin is ideal for fast fixing of parts, especially when the pins are constantly being removed and relocked. Pull up the knob, as the pin is pulled as well so as to allow users to quickly adjust expansion tubing. Insert back after release the knob. This pull pin can clamped the tubing with tightened by a hand (no tools needed).
Features
- RoHS REACH compliant.
- Pull and release process smoother.
- Thread is class 2.
- Flame-proof, heat-resistant, anti-UV properties.
- The head knob has a matte finish.
- The head knob does not hurt hands, no sharp angles or burrs.
- The knob is easy to tight with a hand. the best design of beauty and grip.
- The metal is shiny and detailed.
- Zinc plated metal, stable corrosion resistance.
- The fitting tolerance between metal parts is small, reducing sway.
- The rounded corner of the Plunger's front end increases smoothness of insertion.
- The chamfered front end of the screw makes assembly smoother and reduces wear on the mating end face.
Dimensions

Thread Size
- M8 x 1.0
Thread Material
- Steel
Screw Length(mm/inch)
- 20 / 0.79
Plunger Diameter(mm)
- 4
Metal Finishing
- zinc plated with trivalent
External Diameter(mm)
- 21~24
External Height(mm)
- 21~24
External Material
- PA6+GF
External Shape
- Circle
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Small Indexing Plunger with Circle Clamping Knob, M8 x 1.0 x 20mm, D21, pin4 | Achieve Ergonomic Efficiency with Adjustable Handles for Machinery
Based in Taiwan since 1994, UJEN DEVELOPMENT CO., LTD. expertise in manufacturing high-quality Small Indexing Plunger with Circle Clamping Knob, M8 x 1.0 x 20mm, D21, pin4, hand screws, knob screws, adjustable handles, grip knobs, and indexing plungers. Their commitment to customization and precision ensures each component, from hand screws to indexing plungers, meets rigorous standards. This dedication positions UJEN as a leader in supplying durable and reliable industrial components to global markets.
UJEN Development Co., Ltd. is a leading manufacturer of precision-engineered hand screws, knob screws, plastic knobs, adjustable handles, and indexing plungers for a variety of industrial needs. Our 45-year legacy, combined with ISO 9001:2015 certification, underscores our commitment to quality, innovation, and customer satisfaction. Specializing in custom solutions, we excel in professional moldmaking, enhancing equipment functionality across industries.
UJEN has been offering customers high-quality hand screws for industrial machinery since 1994, both with advanced technology and 47 years of experiences, UJEN ensures each customer's demands are met.