This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X250H, 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 SI50X250H
The AirTAC SI50 Standard Cylinder SI50X250H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X250H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X250H
- 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 SI50X250H
The AirTAC SI50X250H is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 250mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50X250H, which maintains the exact ISO 15552 mounting interface, stroke, output force and port size.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SKU lacks a magnet (-S) so it cannot take a CS1-B/DS1-B sensor. It includes the -H Viton seal for 0-150C environments.
Airtac SI50 Standard Cylinder SI50X250H Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X250H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X250H |
| Bore size | Ø50 mm |
| Stroke | 250 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 SAI50X250H 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 SAI50X250H 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 SI50X250H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×250 | 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 SI50X250H Is Used
Hot End Ejection
Uses the -H Viton seal for 0-150C environments to push parts out of heated molding zones with 982N force.
High-Temp Diverting
Actuates diverter arms on warm material handling lines, providing a safe 589N working load over the 250mm travel.
Oven Door Actuation
Opens and closes industrial curing oven doors where standard NBR seals would degrade, requiring no sensor.
Replacing the Airtac SI50 Standard Cylinder SI50X250H with the SAI50X250H
To replace this SI50X250H, order the SAI50X250H and confirm the ISO 15552 mounting interface, 50mm bore, 250mm stroke, G1/4 port and -H Viton seal. Because this specific SKU lacks a magnet, it cannot accept position sensors; if sensing is needed, order an SAI50X250HS. Sizing both ways: a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore yields 1559N. At 250mm stroke, ensure adequate guide support to prevent rod bending and side-load wear. For load holding on air loss, note that a plain cylinder drifts and the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X250H
- ✓ 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 SI50X250H FAQ
Yes, the SI50X250H is discontinued. The direct replacement is the SAI50X250H. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 250mm stroke, G1/4 port and mounting interface.
The G1/4 port feeds a 50mm bore yielding 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N at 0.9MPa, and a 200kgf max at 1.0MPa. The 250mm stroke operates at 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X250H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X250H replacement — usually within 7-8 hours.