This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X400SN, 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 SI40X400SN
The AirTAC Airtac SI40 Standard Cylinder SI40X400SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 400mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X400SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke400 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X400SN
- 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 SI40X400SN
The AirTAC SI40X400SN is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 400mm stroke. Generating 628N push force at 0.5MPa, it features a G1/4 air port, M12x1.25 rod thread, and 27mm adjustable air cushions. The direct replacement is the SAI40X400SN, matching the exact ISO 15552 mounting interface, bore, force, and porting for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. This SI unit includes a -S magnet for CS1-B/DS1-B switches and an -N NBR seal (-20 to +70 C). Note that plain cylinders drift without live air; for load holding, consider the SAIL lock or BSAI clamp-lock variants the SI line lacked.
Airtac SI40 Standard Cylinder SI40X400SN Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X400SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X400SN |
| Bore size | Ø40 mm |
| Stroke | 400 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 SAI40X400SN 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 SAI40X400SN 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 SI40X400SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | 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 SI40 Standard Cylinder SI40X400SN Is Used
Package Diversion
Drives 400mm stroke routing gates on packaging lines, utilizing the 628N push force at 0.5MPa to deflect moderate-weight cartons reliably.
Component Ejection
Pushes machined parts out of a fixture with 879N at 0.7MPa, using the M12x1.25 rod thread to mount custom ejection blades.
Replacing the Airtac SI40 Standard Cylinder SI40X400SN with the SAI40X400SN
To replace the SI40X400SN, order the SAI40X400SN. Confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port, and the -S magnet for current AirTAC switches. The 400mm stroke requires external guides to prevent rod bending under side loads. If you need more force, the 50mm bore yields 982N push at 0.5MPa; if less is acceptable, the 32mm bore provides 402N. Because standard cylinders do not hold load on air loss (cushions only decelerate), use an external pilot check valve or the SAIL/BSAI lock variants for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X400SN
- ✓ 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 SI40X400SN FAQ
Yes, the SI40X400SN is discontinued. The direct replacement is the SAI40X400SN. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 400mm stroke, G1/4 port, and mounting interface. The SAI simply upgrades the piston seal to two Y-shaped elements for lower start-up pressure.
The 40mm bore uses a G1/4 air port. Force output is 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. It operates at 30-800mm/s with a 16mm rod and M12x1.25 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X400SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X400SN replacement — usually within 7-8 hours.