SMC CQ2B20-30D Compact Cylinder 20 mm Bore, 30 mm Stroke

A short-body compact cylinder for tight spaces

CQ2B20-30D is a compact, double-acting, single-rod air cylinder from the SMC CQ2 series. The body is a short square block with through holes, so it can be bolted straight to a frame, which makes it popular for clamping, pushing, stopping and small lifting jobs where a normal round-body cylinder would not fit.

The code reads CQ2 (series, without an auto switch; CDQ2 has a built-in magnet), B (through-hole mounting, the standard type), 20 (the 20 mm bore), 30 (the 30 mm stroke) and D (double acting). No body-option letter is given, so the rod end has a female thread, and no port-type letter is given, so the ports for the 20 mm size are M5 x 0.8.

Technical specifications

Why the kinetic energy limit matters

A compact cylinder has no air cushion, so the end of the stroke is taken up by the cover and, if fitted, the rubber bumper. The catalogue limits the energy for the 20 mm bore to 0.055 J, or 0.110 J when the rubber bumper option (code C) is added. A load of 0.5 kg moving at 0.4 m/s carries 0.04 J, which is inside the limit; the same load at 0.5 m/s carries 0.0625 J and is not. These values are derived from the standard formula, not catalogue statements.

Use speed controllers, or choose the C bumper, to keep the energy within the limit; avoid using the cylinder as its own end stop under heavy impact.

Options and mounting

The through-hole mounting can be replaced by foot, rod flange, rear flange or double-clevis brackets, listed as CQ-L020, CQ-F020 and CQ-D020 for this bore. Options include both-end tapped bodies (A), male rod-end thread (M), rubber bumper (C), and a version with a boss on the head side (F). Air-hydro and non-rotating types sit in the same family.

Mount the cylinder so that the rod is not bent by the load; the catalogue recommends aligning the rod and the workpiece or using a floating joint.

Related SMC products: SMC CXSM20-100 Dual Rod Cylinder 20 mm Bore, SMC MGPM40-25Z Compact Guide Cylinder 40 mm Bore, SMC CA2B50-100 Tie Rod Air Cylinder 50 mm Bore, SMC CG1BN40-100 Round Body Air Cylinder 40 mm Bore, SMC MGQM25-30 Compact Guide Cylinder 25 mm, Slide Bearing and SMC CRQ2BS20-90 Compact Rotary Actuator Size 20, 90 deg.

Documents and quotation

The SMC CQ2 catalogue PDF below has the how-to-order page, specifications, mass and force tables and dimensions. Please confirm mounting, stroke, thread and switch needs before ordering. More cylinders are listed under Pneumatic Cylinders. Seven Star LLC is an independent supplier and quotes the exact code on request.

CQ2B20-30D Spare Parts & Mounting Brackets

Through-hole mounting bolts for the CQ2B, which are hexagon socket head cap screws in zinc-chromated chromium molybdenum steel, are available as an option. Order them as CQ-M… with the length that matches the stroke and switch configuration, as listed in the catalogue.

How the CQ2B20-30D Compact Cylinder Works

The CQ2B20-30D is a double-acting cylinder. Compressed air fed to the head-side port pushes the 20 mm piston and its rod out by 30 mm, and air fed to the rod-side port returns it. Because the CQ2 body is only slightly longer than the stroke, it fits where a conventional cylinder with separate end covers would not. The square body with through holes allows the cylinder to be bolted directly from either end, which avoids extra brackets. The theoretical force is the piston area multiplied by the operating pressure, which matches the catalogue values of 157 N out and 118 N in at 0.5 MPa.

Selection & Ordering Guide

• CQ2 / CDQ2: choose CDQ2B20-30D if auto switches will be fitted, because the built-in magnet is needed for position sensing.
• Mounting: B through-hole is the standard type. Brackets for foot, flange or clevis mounting are separate part numbers, listed above.
• Body options: M male rod end, C rubber bumper, A both-ends tapped, F with boss on head side.
• Port thread: M5 × 0.8 for the 20 mm bore.
• Made to order: examples include -XB6 heat-resistant (to 150°C, without auto switch), -XB7 cold-resistant (–40°C), -XB9 low speed (10 to 50 mm/s), -XC4 heavy-duty scraper and -XC6 stainless steel rod, retaining ring and rod-end nut.
• Variants in the same catalogue: double rod (CQ2W), non-rotating rod, long stroke, anti-lateral load, air-hydro type and cylinders with end lock.

Our team can help confirm the correct ordering code for the CQ2B20-30D or the equivalent CDQ2 variant with switches.

Installation & Maintenance

• Tighten the through-hole mounting bolts to the torque given in the catalogue, and mount on a flat surface.
• Do not apply lateral load to the rod. Use a floating joint when aligning with a guided load.
• Keep the stroke-end kinetic energy within the 0.055 J limit, or 0.110 J with the rubber bumper option. Adjust speed with meter-out speed controllers.
• Supply filtered, dry air. When the seals wear, replace them with the CQ2B20-PS seal kit and fresh grease.

Typical Applications in Oman & the GCC

Short-stroke clamping, ejecting, positioning, stopping and pressing tasks on assembly fixtures, packaging machines, filling lines, test rigs and jigs. Plants in Oman and the wider GCC use the CQ2B20-30D wherever space around the tool or conveyor is limited.

Why Source the CQ2B20-30D from Seven Star LLC

Seven Star LLC supplies SMC compact cylinders, mounting brackets, seal kits, auto switches and speed controllers across Oman and the GCC. Request a quote for the cylinder and accessories together, and our team can help confirm the correct ordering code.