This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X400TC, 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 SI50 Standard Cylinder SI50X400TC
The AirTAC Airtac SI50 Standard Cylinder SI50X400TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 400mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X400TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke400 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X400TC
- 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 SI50 Standard Cylinder SI50X400TC
The AirTAC SI50X400TC is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 400 mm stroke. It delivers 982 N push at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50X400TC, matching the bore, stroke, force, port and TC trunnion mount exactly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. Note this non-magnet SKU cannot take a sensor; legacy CS1-B/DS1-B switches require an -S model.
Airtac SI50 Standard Cylinder SI50X400TC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X400TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X400TC |
| Bore size | Ø50 mm |
| Stroke | 400 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| 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 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X400TC carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X400TC produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X400TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×400 | 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 SI50 Standard Cylinder SI50X400TC Is Used
Pallet Diversion
Actuates a TC-mounted routing gate on a 50 kg pallet line, using the 400 mm stroke to shift loads between parallel conveyors.
Long-Reach Ejection
Pushes machined aluminum parts out of a CNC enclosure, relying on the 400 mm travel and adjustable 30 mm air cushions to stop smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X400TC with the SAI50X400TC
To replace the SI50X400TC, order the SAI50X400TC. Confirm the ISO 15552 TC trunnion interface, 400 mm stroke, G1/4 port (PT/G/NPT thread options) and 20 mm rod. Because this is a non-S SKU, it cannot accept a magnetic sensor. For sizing, the 50 mm bore yields 982 N push at 0.5 MPa; dropping to a 40 mm bore gives 628 N, while a 63 mm bore provides 1559 N. At 400 mm stroke, use external guides to prevent rod bending and side-load wear. The cushion only decelerates; it does not hold load. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X400TC
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X400TC FAQ
Yes, the SI50X400TC is discontinued. The direct replacement is the SAI50X400TC. It is dimensionally interchangeable per ISO 15552, preserving the same 50 mm bore, 400 mm stroke, G1/4 port, 982 N force and TC trunnion mounting interface.
The bore is 50 mm with a G1/4 air port. Force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa. The theoretical maximum is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X400TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X400TC replacement — usually within 7-8 hours.