SMC CDG1BN20-300 Round Cylinder

This is a standard double-acting round cylinder of SMC CG1 series, featuring built-in magnet ring, rubber cushion and basic mounting style. Bore size: 20 mm, stroke: 300 mm. It is applied to linear driving, positioning and clamping of automated equipment.

Model Code Explanation

Code Segment	Description
CDG1	Series code for SMC standard round cylinders: C = Cylinder, D = With built-in magnet ring, G = Standard type, 1 = Single rod & double acting
B	Mounting code: B = Basic type (without mounting accessories), F = Flange type, K = Foot type, T = Trunnion type, etc.
N	Cushion code: N = Rubber cushion, A = Adjustable air cushion
20	Bore size: 20 mm (Standard bores: 20, 25, 32, 40, 50, 63, 80, 100 mm)
-300	Stroke length: 300 mm (Standard stroke: 50~1000 mm; Custom strokes available)

Full Name: Single rod double-acting round cylinder, basic type with built-in magnet ring and rubber cushion, bore 20 mm, stroke 300 mm.

Main Technical Specifications

Category	Specification	Remarks
General Information
Brand / Series	SMC CG1 Series	Industrial standard round cylinder
Model No.	CDG1BN20-300	Standard order number
Mounting Style	Basic type (accessories mountable)	Compliant with ISO 6431
Protection Class	IP40	Dustproof and splash-proof
Operation Characteristics
Operation Mode	Double acting, single rod	Bi-directional pneumatic drive
Built-in Magnet Ring	Yes (marked by D)	Magnetic switch mountable for position detection
Cushion Type	Rubber cushion (marked by N)	Polyurethane cushions at both ends for impact absorption
Dimensions
Bore	20 mm	Standard size
Stroke	300 mm	Standard stroke
Piston Rod Diameter	8 mm	High-strength chrome-plated stainless steel
Barrel Material	Aluminium alloy (Hard anodized)	Lightweight & corrosion-resistant
Piston Rod Material	Stainless steel (SUS304)	Wear-resistant & rust-proof
Weight	Approx. 0.8 kg	With slots for magnetic switches
Performance Parameters
Operating Pressure Range	0.05~1.0 MPa	For compressed air
Max. Operating Pressure	1.0 MPa	Transient peak ≤ 1.2 MPa
Operating Temperature	-10°C ~ +60°C	Standard environment with dry air
Max. Speed	500 mm/s	Subject to load and air supply flow
Theoretical Output Force	31.4 N @ 0.1 MPa / 314 N @ 1.0 MPa	Calculated value under no load
Port Parameters
Port Thread	Rc1/8 (PT1/8)	Standard pneumatic thread
Number of Ports	2 (1 on front cover, 1 on rear cover)	Available for single / double acting connection
Magnetic Switch Slots	Yes (4 slots)	Compatible with SMC D-M9 series switches

Cross-brand & Obsolete Model Replacement

Original Model	Replacement Model	Description
SMC CG1BN20-300	CDG1BN20-300	Upgraded version with built-in magnet ring, fully compatible
FESTO DSBC-20-300-PPVA-N3	CDG1BN20-300	Functionally equivalent; 20 mm bore, 300 mm stroke, double acting with magnet ring
Airtac SE20X300S	CDG1BN20-300	Domestic alternative; Similar dimensions, slightly lower performance
CKD SCA2-CB-20B-300	CDG1BN20-300	Japanese brand alternative; Compatible mounting dimensions
NUMATICS R20X300	CDG1BN20-300	European & American brand alternative; Verify mounting style before replacement

Selection Notes: Confirm full consistency of bore size, stroke, mounting style, cushion type and magnetic switch compatibility for replacement.

Partial Model List of CDG1B Series

Model	Bore (mm)	Stroke (mm)	Mounting Style	Cushion Type	Built-in Magnet Ring	Remarks
CDG1BN20-50	20	50	Basic	Rubber	Yes	Standard model
CDG1BN20-100	20	100	Basic	Rubber	Yes	Standard model
CDG1BN20-150	20	150	Basic	Rubber	Yes	Standard model
CDG1BN20-200	20	200	Basic	Rubber	Yes	Standard model
CDG1BN20-250	20	250	Basic	Rubber	Yes	Standard model
CDG1BN20-300	20	300	Basic	Rubber	Yes	Subject model
CDG1BN20-350	20	350	Basic	Rubber	Yes	Standard model
CDG1BN20-400	20	400	Basic	Rubber	Yes	Standard model
CDG1AN20-300	20	300	Basic	Air cushion	Yes	Adjustable cushion
CDG1BF20-300	20	300	Flange	Rubber	Yes	Front flange mounting
CDG1BK20-300	20	300	Foot	Rubber	Yes	Bottom mounting
CDG1BT20-300	20	300	Trunnion	Rubber	Yes	Oscillating mounting

Common Faults & Troubleshooting

Fault Phenomenon	Possible Causes	Solutions
Cylinder fails to move / Slow movement	1. Insufficient air supply pressure	1. Adjust pressure to 0.4~0.6 MPa
	2. Pipeline blockage / Air leakage	2. Tighten fittings and clean filter
	3. Solenoid valve failure	3. Test solenoid valve and replace if necessary
	4. Piston rod stuck	4. Dismantle to check rod straightness and clean cylinder barrel
Cylinder crawling / Shaking	1. Insufficient lubrication	1. Install air lubricator with ISO VG32 lubricant
	2. Overload	2. Reduce load or use larger bore cylinder
	3. Moisture / impurities in compressed air	3. Fit air dryer and precision filter
	4. Improper cushion adjustment	4. Adjust cushion needle valve for steady deceleration
Air leakage	1. Aged / damaged sealing rings	1. Replace sealing kit (standard repair kit)
	2. Scratched piston rod	2. Repair or replace piston rod and check guide bushing
	3. Loose end cover bolts	3. Tighten end cover bolts diagonally and evenly
	4. Damaged tube fittings	4. Renew air tubes and fittings for good sealing
No signal from magnetic switch	1. Incorrect switch position	1. Reposition switch to align with piston magnet ring
	2. Failed magnet ring	2. Replace cylinder or piston assembly
	3. Damaged switch	3. Test switch continuity and replace if faulty
	4. Wrong wiring	4. Check wiring and correct polarity
Poor cushioning / Loud impact noise	1. Worn cushion pads	1. Replace polyurethane cushion pads
	2. Improper cushion valve setting	2. Gradually adjust needle valve until impact noise disappears
	3. Excessive load inertia	3. Add external buffer or speed control valve
	4. Overhigh air pressure	4. Reduce working pressure and optimize system design
Bent / Deformed piston rod	1. Exposed to radial load	1. Add guide unit to avoid radial force
	2. Large coaxiality error during installation	2. Calibrate installation; keep coaxiality ≤ 0.1 mm/m
	3. Excessive impact force	3. Optimize cushion system to reduce impact
	4. Material fatigue	4. Replace piston rod or use reinforced cylinder

Application & Industry Cases

6.1 Applicable Scenarios

Automated Production Lines: Material handling, workpiece positioning, assembly and pressing

Electronic Manufacturing: PCB transportation, semiconductor packaging and component positioning

Packaging Machinery: Carton forming, sealing, labeling and filling actuators

Food & Beverage Industry: Cap tightening, bottle conveying and filling valve control

Machine Tools: Clamp actuation, worktable positioning and tool changing mechanism

Medical Equipment: Sample delivery and positioning for diagnostic instruments

6.2 Non-recommended Scenarios

Severely corrosive environment: No special anti-corrosion treatment; Not suitable for strong acid, alkali or heavy salt spray. Stainless steel series is recommended.

Oil-free operation: Long-term operation without lubrication accelerates seal wear. PTFE seals are required.

High-frequency & high-speed operation: Not for cycling over 5 times per second. High-speed cylinder series is recommended.

Heavy radial load: Radial force will bend the rod and damage seals. Extra guide mechanism is required.

Extreme temperature: Operation below -10°C or above +60°C impairs sealing performance and service life.

6.3 Typical Application Cases

Case 1: Electronic Component Assembly Line

Application: Positioning for component insertion on PCB

Configuration: CDG1BN20-300 + SMC D-M9B magnetic switch + precision guide rail

Effect: Positioning accuracy ±0.1 mm with excellent repeatability, meeting automated assembly requirements.

Case 2: Carton Sealing Station of Packaging Machine

Application: Folding carton top flaps and tape sealing

Configuration: Two CDG1BN20-300 cylinders working synchronously for dual-side flap folding

Effect: Adjustable speed, reliable cushioning, low noise and higher sealing efficiency.

Case 3: Automotive Parts Inspection Equipment

Application: Clamping and positioning for dimensional inspection of parts

Configuration: CDG1BN20-300 + precision pressure regulator for flexible clamping

Effect: No workpiece damage, stable clamping force and accurate inspection data.

Selection Guidelines & Quick Rules
Bore size: Select by figures (20/25/32/40/50/63/80/100 mm); Calculate output force based on load.
Stroke: Standard range 50~1000 mm; Custom strokes are available.
Mounting type: Recognized by letters: B=Basic, F=Flange, K=Foot, T=Trunnion.
Cushion type: Recognized by suffix: N=Rubber cushion, A=Adjustable air cushion.
Magnet ring: CDG1 = With built-in magnet ring; CG1 = Without magnet ring.
Replacement rule: Bore, stroke, mounting style and cushion type must be identical.

Packaging & Order Note: 1 unit per package, minimum order quantity 1 unit. It is recommended to prepare 2~3 units as spares for general industrial automation.

Recommended Accessories: SMC D-M9 series magnetic switches, AC series filters, AR series pressure regulators, SY series solenoid valves.