This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X300SLB, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI40 Standard Cylinder SI40X300SLB
The AirTAC Airtac SI40 Standard Cylinder SI40X300SLB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X300SLB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X300SLB
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI40 Standard Cylinder SI40X300SLB
The AirTAC SI40X300SLB is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 300mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this unit with the SAI40X300SLB, a direct replacement sharing the exact ISO 15552 mounting interface, LB foot accessory, and output force.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S code means a piston magnet for CS1-B/DS1-B sensors, though the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X300SLB Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X300SLB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X300SLB |
| Bore size | Ø40 mm |
| Stroke | 300 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X300SLB carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X300SLB produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X300SLB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI40 Standard Cylinder SI40X300SLB Is Used
Package Diversion
Actuates routing gates on packaging lines, using the 300mm stroke to clear standard totes safely.
Vertical Lift Stops
Raises lightweight pallet stops up to 32 kg, benefiting from the LB foot mount for stable base fixation.
Clamp Actuation
Drives mid-force clamping arms holding 377 N workloads securely during light machining operations.
Replacing the Airtac SI40 Standard Cylinder SI40X300SLB with the SAI40X300SLB
To replace the SI40X300SLB, order the SAI40X300SLB. Confirm the ISO 15552 interface, 40mm bore, 300mm stroke, G1/4 port (PT/G/NPT threads), LB foot mounting, and the -S magnet. If you need less force, a 32mm bore yields 402 N push; for more, a 50mm bore yields 982 N. Because this is a 300mm stroke, use an external guide to prevent rod bending and side-load wear. A plain cylinder drifts without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X300SLB
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X300SLB FAQ
Yes, the SI40X300SLB is discontinued. The direct replacement is the SAI40X300SLB. It shares the identical ISO 15552 mounting interface, 40mm bore, 300mm stroke, output force, G1/4 port, and LB mount, fitting existing fixtures perfectly.
This 40mm bore cylinder has a G1/4 air port. It provides 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, and 1130 N push at 0.9 MPa. The theoretical maximum force is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X300SLB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X300SLB replacement — usually within 7-8 hours.