This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X312S, 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 SI63X312S
The AirTAC Airtac SI63 Standard Cylinder SI63X312S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 312mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63X312S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke312 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63X312S
- 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 SI63X312S
The AirTAC SI63X312S is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 312mm stroke. It delivers 1559 N push force at 0.5 MPa via a G3/8 port. AirTAC replaced this legacy unit with the SAI63X312S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI family also adds SAIL lock, SAIF valve, and BSAI clamp-lock variants the SI lacked.
Airtac SI63 Standard Cylinder SI63X312S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X312S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X312S |
| Bore size | Ø63 mm |
| Stroke | 312 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 SAI63X312S 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 SAI63X312S 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 SI63X312S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×312 | 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 SI63X312S Is Used
Package Diverting
Drives diverting arms on packaging lines where the 1559 N push force at 0.5 MPa easily redirects standard cartons.
Material Lowering
Controls the descent of light fixtures, using the adjustable 30mm air cushions to decelerate the 312mm travel smoothly.
Replacing the Airtac SI63 Standard Cylinder SI63X312S with the SAI63X312S
To replace the SI63X312S, order the SAI63X312S and confirm the ISO 15552 interface, 312mm stroke, G3/8 port (PT/G/NPT thread), M16x1.5 rod, and mounting accessory (LB, FA, CA, TC). The -S magnet pairs with legacy CS1-B/DS1-B switches, though the SAI replacement uses current AirTAC sensors. For sizing, the 63mm bore yields 1559 N push at 0.5 MPa; dropping to a 50mm bore gives 982 N, while an 80mm bore provides 2513 N. Because 312mm exceeds typical short strokes, use an external guide to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X312S
- ✓ 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 SI63X312S FAQ
Yes, the SI63X312S is discontinued. The direct replacement is the AirTAC SAI63X312S. It is dimensionally interchangeable per ISO 15552, matching the 63mm bore, 312mm stroke, G3/8 port, and mounting fixtures.
The 63mm bore uses a G3/8 port. At 0.5 MPa it provides 1559 N push and 1402 N pull force. At 0.7 MPa push is 2182 N, and at 0.9 MPa it is 2805 N. The theoretical maximum force is 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X312S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X312S replacement — usually within 7-8 hours.