This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X104S, 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 SI50X104S
The AirTAC Airtac SI50 Standard Cylinder SI50X104S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 104mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X104S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke104 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X104S
- 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 SI50X104S
The AirTAC SI50X104S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 104mm stroke. It delivers a push force of 982 N at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X104S, a direct upgrade retaining the exact same interface, bore, stroke, output force, and mounting accessories.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original SI50X104S includes a piston magnet for CS1-B/DS1-B switches, while the SAI family expands options with SAIL lock, SAIF valve, and BSAI clamp-lock variants.
Airtac SI50 Standard Cylinder SI50X104S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X104S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X104S |
| Bore size | Ø50 mm |
| Stroke | 104 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 SAI50X104S 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 SAI50X104S 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 SI50X104S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×104 | 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 SI50X104S Is Used
Mid-Force Clamping
Secures workholding fixtures in CNC machining, utilizing the 982 N push force to lock medium-sized metal components during milling operations.
Package Diversion
Actuates routing gates on packaging lines, where the 104mm stroke provides rapid movement and the 50kg vertical lift capacity handles product redirects.
Pallet Stops
Controls pallet flow on accumulation conveyors, using adjustable air cushions to decelerate loads smoothly without rebound at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X104S with the SAI50X104S
To replace the SI50X104S, order the SAI50X104S direct equivalent, verifying your ISO 15552 mounting interface, G1/4 port thread (PT/G/NPT), M16x1.5 rod thread, and the -S magnet requirement for legacy CS1-B/DS1-B sensors. When sizing, note the 50mm bore yields 982 N push at 0.5 MPa; a neighbouring 63mm bore offers 1559 N if you need more force, while a 40mm bore provides 628 N. Remember that a plain cylinder drifts on air loss—the cushion only decelerates near stroke end—so for load holding consider an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X104S
- ✓ 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 SI50X104S FAQ
Yes, the SI50X104S is discontinued. The direct replacement is the SAI50X104S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 104mm stroke, 982 N force, G1/4 port, and mounting fixtures.
The 50mm bore 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X104S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X104S replacement — usually within 7-8 hours.