This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X45S, 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 SI50X45S
The AirTAC Airtac SI50 Standard Cylinder SI50X45S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 45mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X45S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke45 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X45S
- 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 SI50X45S
The AirTAC SI50X45S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 45mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50X45S. This direct successor matches the exact interface, stroke and force.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S suffix means it has a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X45S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X45S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X45S |
| Bore size | Ø50 mm |
| Stroke | 45 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 SAI50X45S 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 SAI50X45S 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 SI50X45S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×45 | 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 SI50X45S Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with its 45mm stroke and 982N clamping force.
Package Diverting
Provides reliable actuation for routing lightweight goods on production lines.
Gating Mechanisms
Drives sorting gates and stops in material handling systems with a compact 50mm bore.
Replacing the Airtac SI50 Standard Cylinder SI50X45S with the SAI50X45S
To replace this SI50X45S, order the SAI50X45S. Verify the ISO 15552 mounting interface, 50mm bore, 45mm stroke, G1/4 port (PT/G/NPT thread) and your specific mounting accessory. The -S magnet allows position sensing. If sizing up or down, neighbouring bores are 40mm and 63mm; at 0.5MPa this 50mm bore yields 982N push and 825N pull. Note that a plain cylinder drifts on air loss as the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. The SAIF variant offers a built-in valve if needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X45S
- ✓ 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 SI50X45S FAQ
Yes, the SI50X45S is discontinued. The direct replacement is the SAI50X45S. It is dimensionally interchangeable per ISO 15552, keeping the same 50mm bore, 45mm stroke, output force, G1/4 port and mounting interface.
This double-acting cylinder uses a G1/4 air port. It generates 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a maximum theoretical force of 200kgf at 1.0MPa.
Request a Quote for the SAI50X45S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X45S replacement — usually within 7-8 hours.