This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX70, 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 SI40BX70
The AirTAC SI40 Standard Cylinder SI40BX70 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX70, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX70
- 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 SI40BX70
The AirTAC SI40BX70 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 70mm stroke. Featuring a SUS304 stainless piston rod, it delivers 628 N push force at 0.5 MPa and uses a G1/4 air port. The direct replacement is the SAI40BX70, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. For sensing, note this no-S SKU lacks a magnet and cannot take a switch.
Airtac SI40 Standard Cylinder SI40BX70 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX70 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX70 |
| Bore size | Ø40 mm |
| Stroke | 70 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 SAI40BX70 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 SAI40BX70 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 SI40BX70
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×70 | 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 SI40BX70 Is Used
Washdown Clamping
Ideal for food or chemical processing fixtures where the SUS304 stainless rod resists corrosion while providing 628 N of clamping thrust.
Light Machining
Handles short 70mm stroke positioning of small workpieces under CNC stations, operating reliably at 30-800 mm/s.
Package Diverting
Pushes light cartons or totes on sorting lines where a 32 kg safe vertical lift margin is sufficient for the mechanism.
Replacing the Airtac SI40 Standard Cylinder SI40BX70 with the SAI40BX70
To replace this SI40BX70, order the SAI40BX70. Verify the ISO 15552 mounting interface, 40mm bore, 70mm stroke, G1/4 port, and SUS304 rod. Because this SKU lacks a magnet (-S), it cannot accept a CS1-B/DS1-B sensor; if position detection is needed, select a magnet-equipped SAI. For sizing, the 40mm bore yields 628 N push at 0.5 MPa; if less force is needed, a 32mm bore gives 402 N, or step up to a 50mm bore for 982 N. Remember, a standard cylinder drifts without live air; for load holding, use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX70
- ✓ 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 SI40BX70 FAQ
Yes, the SI40BX70 is discontinued. The direct replacement is the SAI40BX70. It is dimensionally interchangeable per ISO 15552, keeping the same 40mm bore, 70mm stroke, G1/4 port, and SUS304 stainless rod.
This 40mm bore double-acting cylinder uses a G1/4 air port and an M12x1.25 rod thread. It generates 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 max of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40BX70
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX70 replacement — usually within 7-8 hours.