This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63BX125N, 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 SI63BX125N
The AirTAC Airtac SI63 Standard Cylinder SI63BX125N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 125mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63BX125N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke125 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63BX125N
- 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 SI63BX125N
The AirTAC SI63BX125N is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore and 125 mm stroke. It delivers 1559 N push force at 0.5 MPa through a G3/8 port. The direct replacement is the SAI63BX125N, which matches the interface, bore, stroke, force and mounting exactly. This specific SKU features a SUS304 stainless steel rod (-B) and NBR seals (-N), but lacks a magnet, meaning it cannot accept position sensors.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life, while the SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked. Note that a plain cylinder drifts without live air; use a pilot check valve or SAIL lock for load holding.
Airtac SI63 Standard Cylinder SI63BX125N Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63BX125N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63BX125N |
| Bore size | Ø63 mm |
| Stroke | 125 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 SAI63BX125N 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 SAI63BX125N 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 SI63BX125N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×125 | 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 SI63BX125N Is Used
Stainless Rod Clamping
Ideal for packaging lines requiring washdown resistance, using the SUS304 rod to actuate clamping arms with 1559 N of push force at 0.5 MPa.
NBR Sealed Diverting
Sort products on ambient temperature conveyors using the NBR seal option, providing reliable 125 mm stroke actuation for routing gates.
Replacing the Airtac SI63 Standard Cylinder SI63BX125N with the SAI63BX125N
To replace the SI63BX125N, order the SAI63BX125N. It is dimensionally interchangeable per the ISO 15552 mounting interface, keeping the 63 mm bore, 125 mm stroke, G3/8 port, M16x1.5 rod thread and 30 mm cushions. Confirm your mounting accessory (LB, FA, TC, etc.) and note this SKU has no magnet, so CS1-B/DS1-B sensors will not function. For sizing, this bore yields 1559 N push at 0.5 MPa; if undersized, the 80 mm bore provides 2513 N. Because it lacks a lock, a plain cylinder drifts on air loss—use an external rod lock or the SAIL/BSAI variants to hold loads. The 125 mm stroke is standard, but always guide the rod to prevent side-load bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63BX125N
- ✓ 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 SI63BX125N FAQ
Yes, the SI63BX125N is discontinued. The direct replacement is the SAI63BX125N. It is dimensionally interchangeable per ISO 15552, retaining the same 63 mm bore, 125 mm stroke, output force, G3/8 port and mounting interface.
This double-acting cylinder uses a G3/8 air port. It generates 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 of 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63BX125N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63BX125N replacement — usually within 7-8 hours.