This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X125CB, 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 SI50X125CB
The AirTAC Airtac SI50 Standard Cylinder SI50X125CB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X125CB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X125CB
- 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 SI50X125CB
The AirTAC SI50X125CB is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 125mm stroke. It delivers 982N push and 825N pull at 0.5MPa through a G1/4 port. AirTAC replaced this EOL unit with the SAI50X125CB direct replacement, featuring the same CB clevis mount, M16x1.5 rod thread, and ISO 15552 mounting interface for exact fixture interchangeability.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. For sensing, note this specific SKU lacks a magnet (-S) and cannot accept CS1-B/DS1-B switches. For high heat, Viton H seals raise the limit to 150C.
Airtac SI50 Standard Cylinder SI50X125CB Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X125CB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X125CB |
| Bore size | Ø50 mm |
| Stroke | 125 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 SAI50X125CB 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 SAI50X125CB 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 SI50X125CB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×125 | 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 SI50X125CB Is Used
Package Diverting
Actuates CB-mounted pivot arms to redirect cartons on a packaging line, utilizing the 982N push force at 0.5MPa to reliably shift loads up to 589N.
Pallet Positioning
Indexes empty pallets into a loading cell using the 125mm stroke, with the ISO 15552 CB clevis absorbing minor rotational misalignments during the push cycle.
Clamp Actuation
Drives a secondary workholding clamp on a machining fixture, delivering 825N pull force at 0.5MPa to secure parts against vibration.
Replacing the Airtac SI50 Standard Cylinder SI50X125CB with the SAI50X125CB
To replace the SI50X125CB, order the SAI50X125CB keeping the identical 50mm bore, 125mm stroke, G1/4 port, and CB clevis mounting. Because this SKU has no magnet, it cannot support position sensing; if switches are needed, specify the SAI50X125CBS equivalent. A plain cylinder drifts on air loss—the cushions only decelerate—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding. Sizing both ways: a 63mm bore offers 1559N push at 0.5MPa, while dropping to 0.5MPa on this 50mm bore still safely moves a 589N load. At 125mm stroke, rod bending is minimal, but always guide external loads to prevent side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X125CB
- ✓ 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 SI50X125CB FAQ
Yes, the SI50X125CB is discontinued. The direct replacement is the SAI50X125CB. It shares the exact same ISO 15552 mounting interface, 50mm bore, 125mm stroke, G1/4 port, and CB clevis mount, fitting directly into existing fixtures.
This double-acting cylinder features a G1/4 air port and M16x1.5 rod thread. The thrust is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X125CB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X125CB replacement — usually within 7-8 hours.