This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X755S, 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 SI40X755S
The AirTAC Airtac SI40 Standard Cylinder SI40X755S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 755mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X755S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke755 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X755S
- 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 SI40X755S
The AirTAC SI40X755S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 755mm stroke. Delivering 628 N push force at 0.5 MPa via a G1/4 port, it is replaced by the SAI40X755S. This direct upgrade shares identical mounting, bore, stroke, force, and port dimensions. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The -S suffix indicates a built-in piston magnet for legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
The SAI family also introduces variants the SI lacked, such as the SAIL air-released lock, SAIF built-in 4M valve, and BSAI clamp-lock. Rod material options include carbon steel, SUS420J2 (A), or SUS304 (B), and seal options include Viton H for temperatures up to 150 C.
Airtac SI40 Standard Cylinder SI40X755S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X755S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X755S |
| Bore size | Ø40 mm |
| Stroke | 755 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 SAI40X755S 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 SAI40X755S 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 SI40X755S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×755 | 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 SI40X755S Is Used
Long-Stroke Diversion
Drives 755mm pusher arms on packaging lines to redirect products, utilizing the 628 N force at 0.5 MPa with external guides to prevent rod bending.
Parts Ejection
Ejects machined components from CNC fixtures, where the adjustable 27mm air cushions decelerate the 16mm rod smoothly at stroke ends.
Replacing the Airtac SI40 Standard Cylinder SI40X755S with the SAI40X755S
To replace the SI40X755S, order the SAI40X755S, confirming the ISO 15552 mounting interface, 40mm bore, 755mm stroke, G1/4 port (PT/G/NPT thread), and mounting accessory. The -S magnet must be specified to retain sensor compatibility. For sizing alternatives, a 32mm bore provides 402 N push at 0.5 MPa, while a 50mm bore offers 982 N. At 755mm, this stroke is within the 1200mm max standard but requires external guides to prevent rod bending and side-load damage. A plain cylinder does not hold load on air loss; 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 → SAI40X755S
- ✓ 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 SI40X755S FAQ
Yes, the SI40X755S is discontinued. The direct replacement is the SAI40X755S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 755mm stroke, 628 N force, G1/4 port, and mounting interface.
The 40mm bore cylinder has a G1/4 air port. It delivers 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical max force of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X755S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X755S replacement — usually within 7-8 hours.