This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X250SFB, 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 SI63X250SFB
The AirTAC Airtac SI63 Standard Cylinder SI63X250SFB 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 SAI63X250SFB, 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 → SAI63X250SFB
- 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 SI63X250SFB
The AirTAC SI63X250SFB is a discontinued double-acting ISO 15552 profile cylinder featuring a 63 mm bore and 250 mm stroke. It delivers 1559 N push force at 0.5 MPa through a G3/8 port. AirTAC replaced this legacy unit with the SAI63X250SFB, a direct upgrade sharing the exact same interface, bore, stroke, output force, and FB flange mounting.
The SAI replacement upgrades the piston seal to two Y-shaped one-way elements for low start-up pressure and long life. The -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI63 Standard Cylinder SI63X250SFB Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X250SFB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X250SFB |
| 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 SAI63X250SFB 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 SAI63X250SFB 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 SI63X250SFB
| 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 SI63X250SFB Is Used
Mid-Tonnage Pressing
Applies 1559 N of push force at 0.5 MPa for seating bearings, stamping light sheet metal, or clinching components in automated fixtures.
Pallet Diversion
Uses the 250 mm stroke to push heavy pallets onto secondary conveyor lanes, relying on the FB flange to withstand lateral shifting loads.
Replacing the Airtac SI63 Standard Cylinder SI63X250SFB with the SAI63X250SFB
To replace the SI63X250SFB, order the SAI63X250SFB. Confirm the ISO 15552 mounting interface, 63 mm bore, 250 mm stroke, G3/8 port, and FB flange accessory. The -S magnet enables CS1-B/DS1-B switches (the SAI uses current AirTAC switches). Sizing both ways: a 50 mm bore yields 982 N push at 0.5 MPa, while an 80 mm bore yields 2513 N. At 250 mm stroke, check side-load and rod-bending limits, using a guide to prevent binding. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Rod material options include carbon steel, SUS420J2 (A), and SUS304 (B); seals include Viton H for high temp.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X250SFB
- ✓ 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 SI63X250SFB FAQ
Yes, the SI63X250SFB is discontinued. The direct replacement is the SAI63X250SFB. It shares the same ISO 15552 mounting interface, 63 mm bore, 250 mm stroke, output force, G3/8 port, and FB flange, fitting directly into existing fixtures.
The 63 mm bore features a G3/8 port and M16x1.5 rod thread. 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 max force of 318 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X250SFB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X250SFB replacement — usually within 7-8 hours.