This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63BX125STC, 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 SI63BX125STC
The AirTAC SI63 Standard Cylinder SI63BX125STC 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 SAI63BX125STC, 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 → SAI63BX125STC
- 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 SI63BX125STC
The AirTAC SI63BX125STC is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 125mm stroke. Built with an extruded aluminum barrel, it delivers 1559 N push force at 0.5 MPa. The direct replacement is the SAI63BX125STC, which matches the original bore, stroke, G3/8 port, and TC trunnion mounting interface for a seamless fixture swap.
The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. This specific SI unit features a SUS304 stainless steel rod for corrosion resistance and a built-in magnet for CS1-B/DS1-B sensors. Note that a plain cylinder drifts without live air; for load holding, consider the SAIL lock or BSAI clamp-lock variants.
Airtac SI63 Standard Cylinder SI63BX125STC Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63BX125STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63BX125STC |
| 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 SAI63BX125STC 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 SAI63BX125STC 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 SI63BX125STC
| 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 SI63BX125STC Is Used
Stainless Rod Clamping
Leverages the SUS304 rod for corrosion resistance while providing 1559 N of clamping force at 0.5 MPa in humid manufacturing environments.
TC Mount Diversion
Uses the ISO 15552 TC trunnion interface to pivot and actuate a 125mm stroke package routing gate along a 63mm bore assembly line.
Replacing the Airtac SI63 Standard Cylinder SI63BX125STC with the SAI63BX125STC
To replace the SI63BX125STC, order the SAI63BX125STC, confirming the ISO 15552 TC trunnion mount, 63mm bore, 125mm stroke, G3/8 port, and the -S magnet for current AirTAC switches. When sizing both ways, a 50mm bore yields 982 N push at 0.5 MPa, while an 80mm bore yields 2513 N; this 63mm unit provides 1559 N push and 1402 N pull at 0.5 MPa, with a 318 kgf maximum at 1.0 MPa. If your application requires holding a load on air loss, the standard cylinder will drift because the cushion only decelerates at stroke end; use an external pilot check valve or the SAIL/BSAI lock variants. The 125mm stroke is under 300mm, so rod-bending side loads are minimal, but always verify guide alignment.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63BX125STC
- ✓ 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 SI63BX125STC FAQ
Yes, the AirTAC SI63BX125STC is discontinued. The direct replacement is the SAI63BX125STC. It is dimensionally interchangeable per ISO 15552, retaining the exact same 63mm bore, 125mm stroke, G3/8 port, and TC mounting interface.
The 63mm bore features a G3/8 air port and a 20mm rod. 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 SAI63BX125STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63BX125STC replacement — usually within 7-8 hours.