This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63BX250S, 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 SI63 Standard Cylinder SI63BX250S
The AirTAC Airtac SI63 Standard Cylinder SI63BX250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 250mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63BX250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke250 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63BX250S
- 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 SI63 Standard Cylinder SI63BX250S
The AirTAC SI63BX250S is a discontinued double-acting ISO 15552 profile cylinder featuring a 63 mm bore, 250 mm stroke, and a SUS304 stainless steel piston rod. Delivering 1559 N push force at 0.5 MPa, it is directly replaced by the SAI63BX250S. This direct upgrade shares the exact ISO 15552 mounting interface, G3/8 port, and stroke, while adding an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. The -S magnet supports CS1-B/DS1-B sensors.
The SAI family also introduces lock and valve variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock. Note that a standard cylinder drifts without live air; use these lock variants or external pilot check valves for load holding.
Airtac SI63 Standard Cylinder SI63BX250S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63BX250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63BX250S |
| Bore size | Ø63 mm |
| Stroke | 250 mm |
| Acting type | Double acting |
| Port size | G3/8 |
| 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 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI63BX250S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø63mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 kgf | |
The SAI63BX250S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI63 Standard Cylinder SI63BX250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×250 | 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 SI63 Standard Cylinder SI63BX250S Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, using the SUS304 rod to clamp parts reliably with 1559 N of push force.
Vertical Lifting Gates
Suitable for raising lightweight access gates or pallets up to 79 kg, utilizing the built-in magnet for position feedback.
Replacing the Airtac SI63 Standard Cylinder SI63BX250S with the SAI63BX250S
To replace the SI63BX250S, order the SAI63BX250S. It drops into existing fixtures via the identical ISO 15552 mounting dimensions, matching the 63 mm bore, 250 mm stroke, M16x1.5 rod thread, and G3/8 port. Retain your mounting accessory (LB, FA, TC, etc.) and confirm the -S magnet for current AirTAC switch compatibility. If downsizing, a 50 mm bore yields 982 N push at 0.5 MPa; if upsizing, an 80 mm bore provides 2513 N. Because this is a 250 mm stroke, ensure adequate guide support to prevent rod bending under side loads. For applications requiring load holding on air loss, select the SAIL or BSAI lock variant, as standard cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63BX250S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI63 Standard Cylinder SI63BX250S FAQ
Yes, the SI63BX250S is discontinued. The direct replacement is the SAI63BX250S. It is dimensionally interchangeable per ISO 15552, retaining the same 63 mm bore, 250 mm stroke, G3/8 port, and mounting interface.
This 63 mm bore cylinder features a G3/8 air port. It delivers 1559 N push and 1402 N pull at 0.5 MPa, 2182 N push at 0.7 MPa, 2805 N push at 0.9 MPa, and a theoretical maximum force of 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63BX250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63BX250S replacement — usually within 7-8 hours.