This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X250SH, 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 SI40X250SH
The AirTAC Airtac SI40 Standard Cylinder SI40X250SH 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 SAI40X250SH, 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 → SAI40X250SH
- 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 SI40X250SH
The AirTAC SI40X250SH is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 250mm stroke, and a G1/4 air port. Delivering 628N push force at 0.5MPa, it is replaced by the SAI40X250SH. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, output force, and port size for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The H seal option enables 0-150C operation. The original -S magnet supports CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X250SH Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X250SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X250SH |
| 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 SAI40X250SH 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 SAI40X250SH 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 SI40X250SH
| 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 SI40X250SH Is Used
Mid-Force Part Ejection
Uses the 628N push force at 0.5MPa to eject machined aluminium components from a fixture, relying on the 250mm stroke to clear the workspace entirely.
Package Diverting
Actuates a routing gate along a packaging line, where the 32kg safe vertical lift capacity and 250mm travel smoothly redirect moderate-weight cartons.
Pallet Stopper Gate
Functions as an indexing stop for pallets, utilizing the adjustable 27mm air cushions to decelerate loads smoothly without requiring external shock absorbers.
Replacing the Airtac SI40 Standard Cylinder SI40X250SH with the SAI40X250SH
To replace the SI40X250SH, order the SAI40X250SH. Confirm the ISO 15552 mounting interface, 40mm bore, 250mm stroke, G1/4 port (PT/G/NPT thread), and mounting accessory. The -S magnet allows CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors. For load holding, note a plain cylinder drifts on air loss as cushions only decelerate; use an external rod lock or pilot check valve. The SAIL or BSAI lock variants offer integrated holding. At 250mm stroke, guide rods prevent side-load rod bending. Neighbouring bores: SI32X250 yields 402N push @0.5MPa; SI50X250 yields 982N push @0.5MPa.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X250SH
- ✓ 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 SI40X250SH FAQ
Yes, the AirTAC SI40X250SH is discontinued. The direct replacement is the SAI40X250SH. It features the same ISO 15552 mounting interface, 40mm bore, 250mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The 40mm bore cylinder has a G1/4 air port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum force of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X250SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X250SH replacement — usually within 7-8 hours.