This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X125SLB, 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 SI50X125SLB
The AirTAC SI50 Standard Cylinder SI50X125SLB 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 SAI50X125SLB, 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 → SAI50X125SLB
- 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 SI50X125SLB
The AirTAC SI50X125SLB is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 125mm stroke. It delivers 982N push force at 0.5MPa through a G1/4 port. AirTAC replaced this unit with the SAI50X125SLB, a direct replacement sharing the exact same ISO 15552 mounting interface, LB foot mount, and output force.
The SAI upgrade features a modernized piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The original SI includes a piston magnet for CS1-B/DS1-B sensors, while the SAI family also introduces SAIL, SAIF, and BSAI lock variants previously unavailable.
Airtac SI50 Standard Cylinder SI50X125SLB Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X125SLB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X125SLB |
| 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 SAI50X125SLB 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 SAI50X125SLB 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 SI50X125SLB
| 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 SI50X125SLB Is Used
Package Diversion
Pushes medium-weight cartons at 982N push force onto secondary packaging lines using the LB foot mount.
Clamp Actuation
Secures workpieces during machining operations, relying on the 125mm stroke to clear the tool path.
Replacing the Airtac SI50 Standard Cylinder SI50X125SLB with the SAI50X125SLB
To replace the discontinued SI50X125SLB, order the SAI50X125SLB. Confirm the ISO 15552 interface, 50mm bore, 125mm stroke, G1/4 port, and LB foot mounting accessory. Because this SKU includes the -S magnet, it supports CS1-B/DS1-B switches (the SAI uses current AirTAC sensors). For sizing alternatives, a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore provides 1559N. Note that a plain cylinder drifts on air loss; the air cushion only decelerates the piston near stroke end. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant. Rod material options include carbon steel, SUS420J2, and SUS304.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X125SLB
- ✓ 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 SI50X125SLB FAQ
Yes, the SI50X125SLB is discontinued. The direct replacement is the SAI50X125SLB. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 125mm stroke, G1/4 port, LB mount, and force ratings.
This double-acting cylinder uses a G1/4 port. It generates 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X125SLB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X125SLB replacement — usually within 7-8 hours.