This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX135S, 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 SI40BX135S
The AirTAC Airtac SI40 Standard Cylinder SI40BX135S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 135mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX135S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke135 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX135S
- 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 SI40BX135S
The AirTAC SI40BX135S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 135mm stroke, and a SUS304 stainless steel piston rod. It delivers 628 N of push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI40BX135S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and G1/4 port size.
The SAI upgrade introduces an improved piston seal utilizing two Y-shaped one-way elements for low start-up pressure and extended service life. The SAI family also expands functionality with SAIL, SAIF, and BSAI lock or integrated valve variants that the original SI line lacked.
Airtac SI40 Standard Cylinder SI40BX135S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX135S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX135S |
| Bore size | Ø40 mm |
| Stroke | 135 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 SAI40BX135S 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 SAI40BX135S 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 SI40BX135S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×135 | 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 SI40BX135S Is Used
Stainless Rod Actuation
Ideal for packaging machinery requiring corrosion resistance, utilizing the SUS304 piston rod to push 628 N loads reliably in damp washdown environments.
Mid-Stroke Diverting
The 135mm stroke provides precise lateral movement for routing small to mid-weight components along material handling lines without overextending.
Replacing the Airtac SI40 Standard Cylinder SI40BX135S with the SAI40BX135S
To replace the discontinued SI40BX135S, order the SAI40BX135S. Verify your existing fixture's ISO 15552 mounting interface, the 135mm stroke, G1/4 port threads (PT/G/NPT), and the -S magnet requirement for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). The SUS304 (-B) rod provides corrosion resistance versus standard carbon steel. If sizing up or down, consider the adjacent 32mm bore (402 N push @0.5 MPa) or 50mm bore (982 N push @0.5 MPa). Note that a standard cylinder drifts without live air; the adjustable 27mm cushions only decelerate the piston. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX135S
- ✓ 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 SI40BX135S FAQ
Yes, the SI40BX135S is discontinued. The direct replacement is the SAI40BX135S. It shares the identical ISO 15552 mounting interface, 40mm bore, 135mm stroke, G1/4 port, and output force, fitting directly into existing fixtures.
It features a G1/4 air port. The force ratings are: 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX135S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX135S replacement — usually within 7-8 hours.