This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX5S, 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 SI50BX5S
The AirTAC Airtac SI50 Standard Cylinder SI50BX5S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 5mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX5S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke5 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX5S
- 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 SI50BX5S
The AirTAC SI50BX5S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore, 5 mm stroke, and a SUS304 stainless steel rod. It delivers 982 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50BX5S, matching the bore, stroke, force, port, and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This -S SKU includes a piston magnet for legacy CS1-B/DS1-B sensors, and the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50BX5S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX5S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX5S |
| Bore size | Ø50 mm |
| Stroke | 5 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 SAI50BX5S 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 SAI50BX5S 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 SI50BX5S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×5 | 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 SI50BX5S Is Used
Short-Stroke Clamping
Ideal for tight clamping tasks in machining fixtures where a 5 mm stroke securely holds parts without excessive travel.
Ejector Mechanisms
Provides a quick 5 mm ejection push in automated assembly lines, efficiently clearing small components from dies.
Press-Fit Operations
Delivers 982 N of force at 0.5 MPa for seating small bearings or pins in light-duty press-fit applications.
Replacing the Airtac SI50 Standard Cylinder SI50BX5S with the SAI50BX5S
To replace the discontinued SI50BX5S, order the SAI50BX5S. It is dimensionally interchangeable per the ISO 15552 mounting interface, keeping the exact 50 mm bore, 5 mm stroke, M16x1.5 rod thread, G1/4 port, and SUS304 rod. The -S magnet means you can fit CS1-B/DS1-B switches (the SAI uses current AirTAC switches). If you need more force, the neighboring 63 mm bore yields 1559 N at 0.5 MPa; if less is needed, the 40 mm bore gives 628 N. Because this is a plain cylinder, it will not hold a load without live air—the cushion only decelerates. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant. The 5 mm stroke is very short, so side-load and rod-bending risks are minimal, but ensure rigid mounting to prevent binding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX5S
- ✓ 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 SI50BX5S FAQ
Yes, the AirTAC SI50BX5S is discontinued. The direct replacement is the SAI50BX5S. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 5 mm stroke, G1/4 port, and mounting interface, so it drops directly into existing fixtures.
This double-acting cylinder has a 50 mm bore, a SUS304 stainless steel rod, and a G1/4 port. The force ratings are: 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa. It operates at 30-800 mm/s and includes a magnet for CS1-B/DS1-B sensors.
Request a Quote for the SAI50BX5S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX5S replacement — usually within 7-8 hours.