This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X185, 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 SI50X185
The AirTAC Airtac SI50 Standard Cylinder SI50X185 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 185mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X185, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke185 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X185
- 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 SI50X185
The AirTAC SI50X185 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 185 mm stroke, delivering 982 N push force at 0.5 MPa through its G1/4 port. Because this SKU lacks the -S magnet suffix, it cannot accept a position sensor.
The direct replacement is the SAI50X185, which maintains the exact ISO 15552 mounting interface, M16x1.5 rod thread, and 30 mm cushions. The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure, and adds SAIL, SAIF, and BSAI variants the SI lacked.
Airtac SI50 Standard Cylinder SI50X185 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X185 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X185 |
| Bore size | Ø50 mm |
| Stroke | 185 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 SAI50X185 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 SAI50X185 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 SI50X185
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×185 | 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 SI50X185 Is Used
Package Diverting
Actuates routing gates on sorting lines, using the 982 N thrust to push parcels smoothly without stalling.
Pallet Stopper
Functions as a pneumatic stop for inbound pallets, absorbing impact via the 30 mm adjustable air cushions.
Clamp Actuation
Drives mid-force clamping arms in machining cells, providing reliable holding via its 825 N pull force.
Replacing the Airtac SI50 Standard Cylinder SI50X185 with the SAI50X185
To replace the SI50X185, order the SAI50X185 and verify your ISO 15552 mounting fixture, G1/4 port, and 185 mm stroke. If you need position sensing, select an SAI50X185S model instead, as this base SI unit has no magnet. For higher force, the adjacent 63 mm bore yields 1559 N at 0.5 MPa; for lighter duties, the 40 mm bore gives 628 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding. At 185 mm, rod bending is minimal, but always guide external loads to prevent side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X185
- ✓ 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 SI50X185 FAQ
Yes, the SI50X185 is discontinued. The direct replacement is the SAI50X185, which shares the identical ISO 15552 mounting interface, 50 mm bore, 185 mm stroke, output force, and G1/4 port size for a seamless fixture swap.
The 50 mm bore features a G1/4 air port and provides 982 N push / 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a maximum theoretical force of 200 kgf at 1.0 MPa.
Request a Quote for the SAI50X185
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X185 replacement — usually within 7-8 hours.