This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX650, 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 SI50BX650
The AirTAC SI50 Standard Cylinder SI50BX650 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX650, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX650
- 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 SI50BX650
The AirTAC SI50BX650 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 650mm stroke. It delivers 982 N push and 825 N pull at 0.5 MPa. The direct replacement is the SAI50BX650, matching the ISO 15552 mounting interface, bore, stroke, force, G1/4 port and accessories. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life.
This specific SKU uses a SUS304 stainless steel rod (-B) for corrosion resistance and lacks a magnet, meaning it cannot accept a CS1-B/DS1-B sensor. Note that plain cylinders drift without live air; for load holding, use an external pilot check valve or the SAIL lock variant.
Airtac SI50 Standard Cylinder SI50BX650 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX650 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX650 |
| Bore size | Ø50 mm |
| Stroke | 650 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 SAI50BX650 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 SAI50BX650 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 SI50BX650
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×650 | 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 SI50BX650 Is Used
Long-Stroke Diversion
Drives 650mm routing gates on packaging lines where the 982 N push force easily overcomes friction on guided carriages.
Warehouse Pusher
Pushes totes between gravity roller sections, relying on adjustable end cushions to decelerate the 650mm travel smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50BX650 with the SAI50BX650
To replace the SI50BX650, order the SAI50BX650. Confirm the ISO 15552 mounting interface, the 50mm bore, the 650mm stroke, the G1/4 port (PT/G/NPT thread options), and your mounting accessory. Because this SKU lacks the -S magnet, it cannot support position sensing; if sensing is needed, order the SAI equivalent with an S suffix. For sizing down, a 40mm bore yields 628 N push at 0.5 MPa; for sizing up, a 63mm bore yields 1559 N. At 650mm stroke, prevent rod bending by guiding the load externally to avoid side-load forces. A plain cylinder does not hold load without air; use a pilot check valve or the BSAI clamp-lock variant for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX650
- ✓ 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 SI50BX650 FAQ
Yes, the SI50BX650 is discontinued. The direct replacement is the SAI50BX650. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 650mm stroke, output force, G1/4 port and mounting interface. The SAI simply upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure.
The 50mm bore features a G1/4 air port, a 20mm rod, and an M16x1.5 rod thread. Force output is 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 of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX650
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX650 replacement — usually within 7-8 hours.