This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X125STC, 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 SI63X125STC
The AirTAC Airtac SI63 Standard Cylinder SI63X125STC 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 SAI63X125STC, 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 → SAI63X125STC
- 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 SI63X125STC
The AirTAC SI63X125STC is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 125mm stroke, delivering 1559N push force at 0.5MPa. It features a G3/8 port, M16x1.5 rod thread, and TC trunnion mounting. AirTAC replaced this legacy unit with the SAI63X125STC, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for extended life and lower start-up pressure. For position sensing, your -S magnet works with legacy CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI63 Standard Cylinder SI63X125STC Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X125STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X125STC |
| 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 SAI63X125STC 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 SAI63X125STC 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 SI63X125STC
| 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 SI63X125STC Is Used
Pallet Diversion
Uses the 1559N push force at 0.5MPa to push heavy pallets onto adjacent conveyor lines without stalling.
Clamp Actuation
Provides reliable clamping pressure for mid-weight machined parts during CNC milling operations.
Carton Indexing
Drives packaging materials forward precisely over a 125mm stroke at speeds up to 800mm/s.
Replacing the Airtac SI63 Standard Cylinder SI63X125STC with the SAI63X125STC
To replace the SI63X125STC, order the SAI63X125STC. Confirm the ISO 15552 TC trunnion mounting, 125mm stroke, G3/8 port (PT/G/NPT thread options), and the -S magnet for sensing. If you need more force, the neighbouring 80mm bore yields 2513N at 0.5MPa; if less is required, the 50mm bore provides 982N. Remember that a standard cylinder drifts without live air, as the 30mm adjustable cushions only decelerate at stroke end. For secure load holding, use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X125STC
- ✓ 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 SI63X125STC FAQ
Yes, the SI63X125STC is discontinued. The direct replacement is the SAI63X125STC. It shares the identical ISO 15552 mounting interface, 63mm bore, 125mm stroke, output force, and G3/8 port, fitting your existing fixtures perfectly.
This 63mm bore double-acting cylinder features a G3/8 air port. It delivers 1559N push and 1402N pull at 0.5MPa, 2182N push at 0.7MPa, 2805N push at 0.9MPa, and a maximum theoretical force of 318kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X125STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X125STC replacement — usually within 7-8 hours.