This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX15S, 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 SI50BX15S
The AirTAC Airtac SI50 Standard Cylinder SI50BX15S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 15mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX15S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke15 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX15S
- 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 SI50BX15S
The AirTAC SI50BX15S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 15mm nonstandard stroke, and a SUS304 stainless steel rod. It delivers 982 N push and 825 N pull at 0.5 MPa, utilizing a G1/4 air port and M16x1.5 rod thread. Because this stroke is nonstandard, the exact 15mm travel must be confirmed from the datasheet or custom-ordered.
The direct replacement is the SAI50BX15S, maintaining the same ISO 15552 mounting interface, force, and port size. The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. Note that a plain cylinder drifts without live air; use an external rod lock or the SAIL lock variant for load holding.
Airtac SI50 Standard Cylinder SI50BX15S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX15S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX15S |
| Bore size | Ø50 mm |
| Stroke | 15 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 SAI50BX15S 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 SAI50BX15S 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 SI50BX15S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×15 | 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 SI50BX15S Is Used
Short-Stroke Clamping
Ideal for tight fixture clamping in machining centers, where the 15mm travel and 982 N force securely hold stainless workpieces without excessive retraction space.
Corrosive Ejector
The SUS304 rod option excels in packaging lines ejecting small parts, offering resistance against washdown chemicals while providing rapid 30-800 mm/s actuation.
Valve Diversion
Suitable for actuating diverter valves in material handling, where the compact 50mm bore and 825 N pull force reliably pivot heavy flow gates within a 15mm radius.
Replacing the Airtac SI50 Standard Cylinder SI50BX15S with the SAI50BX15S
To replace the discontinued SI50BX15S, order the SAI50BX15S. Verify your ISO 15552 mounting interface, G1/4 port (PT/G/NPT), and the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). The -B suffix indicates a SUS304 stainless rod for corrosion resistance. Sizing both ways: this 50mm bore yields 982 N push at 0.5 MPa, whereas the neighbouring 40mm bore yields 628 N. If you need to hold a load during air loss, do not rely on the air cushion—it only decelerates near stroke end. Instead, specify the SAIL air-released lock, the BSAI clamp-lock, or an external pilot check valve. For nonstandard 15mm travel, ensure fixture clearance accommodates the short stroke without side-load binding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX15S
- ✓ 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 SI50BX15S FAQ
Yes, the SI50BX15S is discontinued. The direct replacement is the SAI50BX15S. It features the same ISO 15552 mounting interface, 50mm bore, 15mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly while adding an upgraded piston seal.
This double-acting cylinder uses a G1/4 air port. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX15S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX15S replacement — usually within 7-8 hours.