This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X253S, 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 SI50X253S
The AirTAC Airtac SI50 Standard Cylinder SI50X253S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 253mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X253S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke253 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X253S
- 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 SI50X253S
The AirTAC SI50X253S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 253mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50X253S, matching the exact interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL lock, SAIF valve, and BSAI clamp-lock variants the SI lacked. This -S SKU includes a magnet for CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X253S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X253S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X253S |
| Bore size | Ø50 mm |
| Stroke | 253 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 SAI50X253S 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 SAI50X253S 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 SI50X253S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×253 | 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 SI50X253S Is Used
Package Diverting
Ideal for pushing medium-weight cartons off a belt line using the 982 N push force at 0.5 MPa over a 253mm extension.
Clamp Actuation
Provides reliable clamping pressure for machining fixtures, utilizing the 825 N pull force at 0.5 MPa.
Replacing the Airtac SI50 Standard Cylinder SI50X253S with the SAI50X253S
To replace the SI50X253S, order the SAI50X253S direct. Confirm the ISO 15552 mounting interface, 50mm bore, 253mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The built-in magnet (-S) works with legacy CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors. For sizing, a neighbouring 63mm bore yields 1559 N push at 0.5 MPa, while dropping to 40mm gives 628 N. Because stroke is 253mm, ensure guide alignment to prevent rod-bending side loads. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X253S
- ✓ 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 SI50X253S FAQ
Yes, the AirTAC SI50X253S is discontinued. The direct replacement is the SAI50X253S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 253mm stroke, 982 N force, G1/4 port, and mounting fixtures.
This 50mm bore cylinder features a G1/4 air port and M16x1.5 rod thread. It delivers 982 N push and 825 N pull 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X253S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X253S replacement — usually within 7-8 hours.