This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X75SFA, 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 SI50 Standard Cylinder SI50X75SFA
The AirTAC Airtac SI50 Standard Cylinder SI50X75SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 75mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X75SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke75 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X75SFA
- 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 SI50 Standard Cylinder SI50X75SFA
The AirTAC SI50X75SFA is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 75 mm stroke. It delivers 982 N of push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X75SFA, a direct replacement retaining the exact ISO 15552 mounting interface, FA flange, output force, and stroke.
The SAI upgrade features a revised piston seal using two Y-shaped one-way elements for lower start-up pressure and longer life. The original SI utilized CS1-B/DS1-B sensors via its magnet, while the SAI family supports current AirTAC switches and adds lock variants like the SAIL and BSAI that the SI lacked.
Airtac SI50 Standard Cylinder SI50X75SFA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X75SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X75SFA |
| Bore size | Ø50 mm |
| Stroke | 75 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X75SFA carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X75SFA produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X75SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×75 | 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 SI50 Standard Cylinder SI50X75SFA Is Used
Package Diversion
Actuates routing gates on packaging lines where 982 N push force easily deflects medium-weight cartons.
Clamp Actuation
Provides reliable clamping pressure for lightweight aluminum extrusion fixtures in assembly workstations.
Stopper Cylinder
Functions as a pneumatic stop for pallet accumulation zones, handling loads safely within its 50 kg vertical lift capacity.
Replacing the Airtac SI50 Standard Cylinder SI50X75SFA with the SAI50X75SFA
To replace the SI50X75SFA, order the SAI50X75SFA. Confirm the ISO 15552 interface, 50 mm bore, 75 mm stroke, G1/4 port, and FA flange mounting. The S suffix indicates a piston magnet for position sensing; the SAI uses current AirTAC switches, whereas the legacy SI used CS1-B/DS1-B sensors. Sizing both ways: a 50 mm bore gives 982 N push at 0.5 MPa (1374 N at 0.7 MPa), while a neighbouring 40 mm bore yields 628 N. Remember that a standard cylinder does not hold load without live air—the cushion only decelerates. For load holding on air loss, use an external pilot check valve or explore the SAIL and BSAI lock variants. Rod material options include carbon steel, SUS420J2, or SUS304.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X75SFA
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X75SFA FAQ
Yes, the SI50X75SFA is discontinued. The direct replacement is the SAI50X75SFA. It shares the same ISO 15552 mounting interface, 50 mm bore, 75 mm stroke, G1/4 port, and FA flange, fitting directly into existing fixtures.
This double-acting cylinder uses a G1/4 air port. It delivers a push force of 982 N and a pull force of 825 N at 0.5 MPa. At 0.7 MPa the push force is 1374 N, and the theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X75SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X75SFA replacement — usually within 7-8 hours.