This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X250TC, 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 SI40 Standard Cylinder SI40X250TC
The AirTAC Airtac SI40 Standard Cylinder SI40X250TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X250TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X250TC
- 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 SI40 Standard Cylinder SI40X250TC
The AirTAC SI40X250TC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 250mm stroke, delivering 628N push force at 0.5MPa. The direct replacement is the SAI40X250TC, which shares the exact ISO 15552 mounting interface, G1/4 port, and TC trunnion mount. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life.
Because this specific SKU lacks the -S magnet, it cannot accept position switches like the legacy CS1-B/DS1-B sensors. Note that a standard cylinder drifts without live air; for load holding, consider the SAIL lock or BSAI clamp-lock variants.
Airtac SI40 Standard Cylinder SI40X250TC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X250TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X250TC |
| Bore size | Ø40 mm |
| Stroke | 250 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X250TC carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X250TC produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X250TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | 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 SI40 Standard Cylinder SI40X250TC Is Used
Package Diversion
Actuates routing gates on packaging lines using the TC trunnion mount to accommodate slight pivot alignment shifts.
Clamp Actuation
Provides 628N of push force at 0.5MPa to secure medium workpieces during light machining or assembly processes.
Replacing the Airtac SI40 Standard Cylinder SI40X250TC with the SAI40X250TC
To replace the SI40X250TC, order the SAI40X250TC and confirm the ISO 15552 TC trunnion mounting, 40mm bore, 250mm stroke, and G1/4 port. Since this SKU has no -S magnet, you must use external mechanical sensors if position detection is needed. When sizing, the 40mm bore yields 628N push at 0.5MPa; stepping up to the 50mm bore provides 982N, while dropping to 32mm gives 402N. At 250mm stroke, ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder does not hold load without air; use a pilot check valve or explore the SAIL air-released lock and BSAI clamp-lock variants for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X250TC
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X250TC FAQ
Yes, the SI40X250TC is discontinued. The direct replacement is the SAI40X250TC. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 250mm stroke, G1/4 port, and TC mounting interface.
The 40mm bore features a G1/4 air port and a 16mm rod. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X250TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X250TC replacement — usually within 7-8 hours.