This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX50H, 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 SI40BX50H
The AirTAC Airtac SI40 Standard Cylinder SI40BX50H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX50H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX50H
- 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 SI40BX50H
The AirTAC SI40BX50H is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke. Built with an extruded aluminum barrel, it delivers 628 N push force at 0.5 MPa, features a G1/4 port, and includes a Viton H high-temperature seal (0-150 C) alongside a SUS304 stainless steel rod. The direct replacement is the SAI40BX50H, matching the exact ISO 15552 mounting interface, force, and porting.
This SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. Note this SKU lacks a magnet so it cannot take a sensor; if you need holding, the cushion only decelerates, so consider the SAIL or BSAI lock variants.
Airtac SI40 Standard Cylinder SI40BX50H Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX50H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX50H |
| Bore size | Ø40 mm |
| Stroke | 50 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 SAI40BX50H 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 SAI40BX50H 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 SI40BX50H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×50 | 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 SI40BX50H Is Used
High-Temp Clamping
Actuates holding clamps on heated metal fixtures using the Viton H seal and SUS304 rod to resist thermal degradation and corrosion up to 150 C.
Divertor Arm
Drives a short 50mm stroke divertor mechanism on a packaging line, providing 628 N of push force at 0.5 MPa to pivot products efficiently.
Gate Actuation
Controls the opening and closing of process gates in hot environments where standard NBR seals would fail, relying on the FKM compound.
Replacing the Airtac SI40 Standard Cylinder SI40BX50H with the SAI40BX50H
To replace the discontinued SI40BX50H, order the SAI40BX50H. It is dimensionally interchangeable per ISO 15552 mounting-interface dimensions, keeping the same 40mm bore, 50mm stroke, G1/4 port, and M12x1.25 rod thread. Because this specific SKU lacks the -S magnet, it cannot accept a CS1-B or DS1-B sensor; if position detection is required, switch to an SAI40X50S equivalent. The standard carbon steel rod is replaced here by the SUS304 stainless option (-B) for corrosion resistance, and the -H Viton seal handles up to 150 C. A plain cylinder does not hold load without live air, so for drop prevention use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. If sizing up or down, neighboring bores are 32mm and 50mm; at 0.5 MPa the 32mm yields 402 N push while the 50mm yields 982 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX50H
- ✓ 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 SI40BX50H FAQ
Yes, the AirTAC SI40BX50H is discontinued. The direct replacement is the SAI40BX50H. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 50mm stroke, 628 N force, G1/4 port, and mounting interface, but features an upgraded two Y-shaped one-way piston seal for longer life.
The 40mm bore uses a G1/4 air port and an M12x1.25 rod thread. Force output is 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, with 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 SAI40BX50H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX50H replacement — usually within 7-8 hours.