This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X25H, 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 SI50X25H
The AirTAC Airtac SI50 Standard Cylinder SI50X25H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X25H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X25H
- 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 SI50X25H
The AirTAC SI50X25H is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 25 mm stroke. It delivers a push force of 982 N at 0.5 MPa, uses a G1/4 port, and features a high-temperature Viton H seal (0-150 C). Because this SKU lacks a magnet, it cannot accept a position sensor.
The direct replacement is the SAI50X25H, which retains the exact ISO 15552 mounting interface, M16x1.5 rod thread, and 30 mm cushions. The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure.
Airtac SI50 Standard Cylinder SI50X25H Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X25H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X25H |
| Bore size | Ø50 mm |
| Stroke | 25 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 SAI50X25H 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 SAI50X25H 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 SI50X25H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×25 | 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 SI50X25H Is Used
Short-Stroke Clamping
Ideal for high-temperature fixturing where a 982 N push force securely holds workpieces during machining without requiring full stroke travel.
Diversion Gates
Provides rapid 25 mm actuation for routing small parts on a line, with the Viton H seal surviving ambient heat near ovens or dryers.
Ejector Stations
Delivers a fast 30-800 mm/s cycle to eject finished goods, while the ISO 15552 profile barrel drops directly into existing machine jigs.
Replacing the Airtac SI50 Standard Cylinder SI50X25H with the SAI50X25H
To replace the SI50X25H, order the SAI50X25H and confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port, and the Viton H high-temp seal. This non-magnetic SKU cannot take a CS1-B or DS1-B sensor; if sensing is needed, specify an SAI with the magnet option. For sizing both ways: a 40 mm bore gives 628 N push at 0.5 MPa, while a 63 mm bore yields 1559 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or the SAIL/BSAI lock variant to hold loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X25H
- ✓ 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 SI50X25H FAQ
Yes, the AirTAC SI50X25H is discontinued. The direct replacement is the SAI50X25H. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 25 mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures perfectly.
This double-acting cylinder uses a G1/4 air port. At 0.5 MPa it provides 982 N push and 825 N pull force. At 0.7 MPa push is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa.
Request a Quote for the SAI50X25H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X25H replacement — usually within 7-8 hours.