This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX25, 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 SI50AX25
The AirTAC Airtac SI50 Standard Cylinder SI50AX25 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 SAI50AX25, 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 → SAI50AX25
- 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 SI50AX25
The AirTAC SI50AX25 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 25mm stroke. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50AX25. This direct successor shares the exact interface, G1/4 port and M16x1.5 rod thread.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. This SKU lacks a magnet (-S) and cannot take a sensor. The -A rod is SUS420J2 stainless steel.
Airtac SI50 Standard Cylinder SI50AX25 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX25 |
| 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 SAI50AX25 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 SAI50AX25 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 SI50AX25
| 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 SI50AX25 Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with 982 N of push force at 0.5 MPa within a compact 25mm stroke.
Package Diverting
Provides rapid actuation for diverting lightweight goods on packaging lines, operating at speeds of 30-800 mm/s.
Stainless Rod Ejector
The SUS420J2 stainless piston rod offers corrosion resistance for ejecting parts in humid or washdown environments.
Replacing the Airtac SI50 Standard Cylinder SI50AX25 with the SAI50AX25
To replace the SI50AX25, order the SAI50AX25. Verify the ISO 15552 mounting interface, 50mm bore, 25mm stroke, G1/4 port (PT/G/NPT thread options) and SUS420J2 stainless rod. Because this SKU has no magnet, it cannot accept CS1-B/DS1-B sensors. If sensing is required, switch to an SAI50X25S equivalent. For sizing, the 50mm bore yields 982 N push at 0.5 MPa; dropping to a 40mm bore gives 628 N, while a 63mm bore provides 1559 N. This plain cylinder will not hold load on air loss; the cushion only decelerates. For secure holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX25
- ✓ 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 SI50AX25 FAQ
Yes, the AirTAC SI50AX25 is discontinued. The direct replacement is the SAI50AX25. It shares the same ISO 15552 mounting interface, 50mm bore, 25mm stroke, output force, G1/4 port and M16x1.5 rod thread, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/4 air port. It delivers a push force of 982 N and a pull force of 825 N at 0.5 MPa. 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 SAI50AX25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX25 replacement — usually within 7-8 hours.