SMC 10-CUJB20-40D | Clean Room Mini Free Mount Cylinder CUJ Series 20mm Bore 40mm Stroke Double-Acting Extended Stroke

The SMC 10-CUJB20-40D is a clean room specification mini free mount cylinder from the CUJ series with a 20mm bore and 40mm stroke. Part number decoded: CUJ = mini free mount cylinder, B = basic, 20 = bore mm, 40 = stroke mm, D = double-acting. The 40mm stroke significantly exceeds the standard CUJ 30mm maximum catalog stroke at 20mm bore, making this an extended-stroke variant for applications requiring longer travel from the compact CUJ free mount platform.

At 20mm bore delivering approximately 188N at 0.6 MPa, the 40mm stroke extends the CUJ's reach by 33% beyond the standard 30mm maximum. This longer travel enables applications that normally require stepping up to the larger CQ2 compact cylinder series — including extended workpiece transfer, deep-reach fixture engagement, and long-throw shuttle mechanisms — while maintaining the CUJ's ultra-compact free mount form factor. The free mount body installs from any surface without brackets, critical in confined clean room tooling where every millimeter of space matters.

Note that like the CUJB20-35D, this variant does not include the M (magnetic piston) suffix. Verify auto-switch compatibility if position sensing is required for your application. For the standard stroke range with magnetic piston and pre-mounted switch, see CUJB20-30DM-M9PMS. For shorter CUJ travel at 20mm bore, standard options include 15mm, 20mm, 25mm, and 30mm strokes. If you need more than 188N of force with this stroke length, the CDQ2B25 or CDQ2B32 compact cylinders provide higher force. Clean series (10-) fluorine grease, Particle Grade 1. RoHS compliant.