This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX155S, 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 SI40AX155S
The AirTAC Airtac SI40 Standard Cylinder SI40AX155S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 155mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX155S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke155 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX155S
- 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 SI40AX155S
The AirTAC SI40AX155S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 155mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI40AX155S, which matches the exact ISO 15552 mounting interface, stroke, force, and porting for existing fixtures. The 155mm stroke is nonstandard, so confirm availability for the SAI equivalent.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This unit features a SUS420J2 stainless rod (A option) and a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX155S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX155S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX155S |
| Bore size | Ø40 mm |
| Stroke | 155 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 SAI40AX155S 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 SAI40AX155S 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 SI40AX155S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×155 | 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 SI40AX155S Is Used
Clamp Actuation
Drives medium-duty clamping arms on machining fixtures, utilizing the SUS420J2 stainless rod for mild corrosion resistance in wet coolant environments.
Package Diverting
Powers diverting pop-up gates on packaging lines, where the 628N push force at 0.5MPa easily overcomes side friction and redirects cartons.
Replacing the Airtac SI40 Standard Cylinder SI40AX155S with the SAI40AX155S
To replace this SI cylinder, order the SAI40AX155S. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port thread (PT/G/NPT), and the built-in magnet for current AirTAC switches. When sizing both ways, a 32mm bore offers 402N push at 0.5MPa, while a 50mm bore provides 982N. Note that 155mm is a nonstandard stroke. For strokes over 300mm, guide side loads to prevent rod bending. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX155S
- ✓ 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 SI40AX155S FAQ
Yes, the SI40AX155S is discontinued. The direct replacement is the SAI40AX155S. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 155mm stroke, G1/4 port, and mounting interface, but adds an upgraded two Y-shaped one-way piston seal.
This double-acting cylinder has a G1/4 air port. It generates 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. The rod is M12x1.25 thread with a 27mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX155S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX155S replacement — usually within 7-8 hours.