This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X27, 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 SI50X27
The AirTAC Airtac SI50 Standard Cylinder SI50X27 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 27mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X27, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke27 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X27
- 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 SI50X27
The AirTAC SI50X27 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 27 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. Because this stroke is non-standard, the direct replacement is the SAI50X27, sharing the same interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Note this SKU lacks a magnet, so it cannot take a sensor.
Airtac SI50 Standard Cylinder SI50X27 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X27 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X27 |
| Bore size | Ø50 mm |
| Stroke | 27 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 SAI50X27 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 SAI50X27 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 SI50X27
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×27 | 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 SI50X27 Is Used
Short-Stroke Clamping
Ideal for holding parts in machining fixtures where a compact 27 mm stroke provides rapid, high-force clamping at 982 N.
Package Diverting
Suitable for actuating small diverters or gates on conveyor lines, utilizing the 50 mm bore for quick, robust movements.
Ejector Mechanisms
Deployed in ejection stations to push lightweight components or containers out of flow using a brief, powerful stroke.
Replacing the Airtac SI50 Standard Cylinder SI50X27 with the SAI50X27
To replace the SI50X27, order the SAI50X27. Verify the ISO 15552 mounting interface, G1/4 port, and M16x1.5 rod thread. Since this SKU lacks the -S magnet, it cannot support CS1-B/DS1-B sensors; add the magnet if position detection is needed. For sizing, a 40 mm bore gives 628 N push @0.5 MPa, while a 63 mm bore yields 1559 N. The 27 mm stroke is non-standard but mechanically valid. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X27
- ✓ 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 SI50X27 FAQ
Yes, the SI50X27 is discontinued. The direct replacement is the SAI50X27. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 27 mm stroke, output force, G1/4 port, and mounting fixtures.
The G1/4 port bore delivers a push of 982 N and pull of 825 N at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Speed is 30-800 mm/s.
Request a Quote for the SAI50X27
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X27 replacement — usually within 7-8 hours.