This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX5, 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 SI40BX5
The AirTAC Airtac SI40 Standard Cylinder SI40BX5 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 5mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX5, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke5 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX5
- 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 SI40BX5
The AirTAC SI40BX5 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 5mm stroke, delivering 628N push force at 0.5MPa. It features a SUS304 stainless piston rod for corrosion resistance. Because this SKU lacks a magnet, it cannot accept a position switch. The direct replacement is the SAI40BX5, which retains the exact G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two-piece Y-shaped piston seal for lower start-up pressure and extended life. Note that a standard cylinder drifts without live air; for held loads, consider the SAIL lock or BSAI clamp-lock variants, or use an external pilot check valve.
Airtac SI40 Standard Cylinder SI40BX5 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX5 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX5 |
| Bore size | Ø40 mm |
| Stroke | 5 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 SAI40BX5 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 SAI40BX5 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 SI40BX5
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×5 | 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 SI40BX5 Is Used
Short-Stroke Clamping
Ideal for compact 5mm clamping actions in machining fixtures where a 628N push force securely holds non-ferrous workpieces without damaging surfaces.
Corrosive Ejector
The SUS304 stainless rod excels in packaging lines ejecting small parts, resisting moisture while providing rapid 30-800mm/s actuation.
Small Part Pressing
Delivers precise 5mm downward travel for seating bearings or pins, offering a safe 377N working load for delicate assembly operations.
Replacing the Airtac SI40 Standard Cylinder SI40BX5 with the SAI40BX5
To replace the SI40BX5, order the SAI40BX5. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 5mm stroke, G1/4 port, and mounting fixtures. Confirm if you need the stainless rod (-B) or standard carbon steel. This non-magnet SKU cannot support sensing; if you require position feedback, order an SAI variant with the S suffix. For loads needing 879N at 0.7MPa, the 40mm bore is ideal, but if you need less force, step down to a 32mm bore. Because this is a short 5mm stroke, side-load is minimal, but always verify rod alignment. The SAI family also adds SAIF (integrated valve) and SAIL/BSAI (locking) options the SI lacked.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX5
- ✓ 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 SI40BX5 FAQ
Yes, the SI40BX5 is discontinued. The direct replacement is the SAI40BX5. It features the same ISO 15552 mounting interface, 40mm bore, 5mm stroke, G1/4 port, and force output, but uses an upgraded two-piece Y-shaped piston seal for longer life.
The 40mm bore features a G1/4 air port and M12x1.25 rod thread. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa. Speed ranges from 30-800mm/s.
Request a Quote for the SAI40BX5
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX5 replacement — usually within 7-8 hours.