This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX40, 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 SI50BX40
The AirTAC Airtac SI50 Standard Cylinder SI50BX40 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 40mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX40, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke40 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX40
- 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 SI50BX40
The AirTAC SI50BX40 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 40mm stroke, delivering 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50BX40, matching the exact bore, stroke, force, port and ISO 15552 mounting interface for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This specific SKU lacks a magnet (-S) and cannot accept a CS1-B/DS1-B sensor. The -B rod option provides a SUS304 stainless piston rod for corrosion resistance.
Airtac SI50 Standard Cylinder SI50BX40 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX40 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX40 |
| Bore size | Ø50 mm |
| Stroke | 40 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 SAI50BX40 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 SAI50BX40 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 SI50BX40
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×40 | 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 SI50BX40 Is Used
Short-Stroke Clamping
Ideal for holding parts during machining, utilizing the 982 N push force at 0.5 MPa across a tight 40mm travel.
Compact Pressing
Performs light-duty pressing or seating tasks where a 50mm bore and brief 40mm stroke deliver precise force.
Ejector Mechanisms
Suits small ejection stations on automated lines, offering fast 30-800 mm/s actuation without needing sensors.
Replacing the Airtac SI50 Standard Cylinder SI50BX40 with the SAI50BX40
To replace the SI50BX40, order the SAI50BX40 and confirm the ISO 15552 mounting interface, G1/4 port, and M16x1.5 rod thread. Because this SKU lacks a magnet, it cannot support legacy CS1-B/DS1-B switches; order a magnet-equipped SAI variant if sensing is required. Sizing both ways: the 50mm bore yields 982 N push at 0.5 MPa, while a 40mm bore offers 628 N and a 63mm bore provides 1559 N. For load holding, note that a plain cylinder drifts on air loss as the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variants. At 40mm stroke, side-load risks are minimal.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX40
- ✓ 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 SI50BX40 FAQ
Yes, the SI50BX40 is discontinued. The direct replacement is the SAI50BX40, which shares the identical ISO 15552 mounting interface, 50mm bore, 40mm stroke, force, and G1/4 port.
It features a G1/4 port and delivers 982 N push / 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Request a Quote for the SAI50BX40
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX40 replacement — usually within 7-8 hours.