This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X15FB, 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 SI40X15FB
The AirTAC Airtac SI40 Standard Cylinder SI40X15FB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 15mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X15FB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke15 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X15FB
- 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 SI40X15FB
The AirTAC SI40X15FB is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 15mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI40X15FB, which shares the exact ISO 15552 mounting interface, FB flange, and output force.
This SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. Because this specific SI SKU lacks a magnet (-S), it cannot accept a CS1-B or DS1-B sensor. For load holding, note the cushion only decelerates; use an external rod lock or the SAIL lock variant.
Airtac SI40 Standard Cylinder SI40X15FB Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X15FB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X15FB |
| Bore size | Ø40 mm |
| Stroke | 15 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 SAI40X15FB 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 SAI40X15FB 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 SI40X15FB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×15 | 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 SI40X15FB Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with a 628 N push force at 0.5 MPa and a 15mm stroke.
Ejector Gate
Provides rapid 30-800 mm/s actuation to push items off a line using the FB flange mount.
Replacing the Airtac SI40 Standard Cylinder SI40X15FB with the SAI40X15FB
To replace the SI40X15FB, order the SAI40X15FB ensuring the ISO 15552 FB flange, 40mm bore, 15mm stroke, and G1/4 port match your fixture. This non-magnetic SKU cannot host a sensor; if position detection is needed, select an SAI40X15FBS instead. For sizing down, a 32mm bore yields 402 N push at 0.5 MPa; sizing up to 50mm provides 982 N. A plain cylinder drifts on air loss, so for suspended loads use a pilot check valve or the BSAI clamp-lock variant. The 15mm stroke is very short, so side-load risks are minimal, but ensure the FB flange alignment is true.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X15FB
- ✓ 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 SI40X15FB FAQ
Yes, the SI40X15FB is discontinued. The direct replacement is the SAI40X15FB. It matches the ISO 15552 mounting interface, 40mm bore, 15mm stroke, FB mount, and G1/4 port exactly.
The G1/4 port feeds a 40mm bore yielding 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N at 0.9 MPa, and a 128 kgf max at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X15FB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X15FB replacement — usually within 7-8 hours.