This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X40SH, 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 SI50 Standard Cylinder SI50X40SH
The AirTAC Airtac SI50 Standard Cylinder SI50X40SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 40mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X40SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke40 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X40SH
- 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 SI50 Standard Cylinder SI50X40SH
The AirTAC SI50X40SH is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 40mm stroke, and a G1/4 air port. Delivering a push force of 982 N at 0.5 MPa, it is directly replaced by the direct replacement SAI50X40SH, which shares the exact ISO 15552 mounting interface, bore, stroke, output force, and porting. The SAI upgrade introduces an upgraded piston seal featuring two Y-shaped one-way elements for low start-up pressure and extended life.
This -H variant includes a Viton FKM seal rated for 0 to 150 C, and the -S magnet supports legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). For load-holding, note that a plain cylinder drifts on air loss; use a pilot check valve or the SAIL lock variant.
Airtac SI50 Standard Cylinder SI50X40SH Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X40SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X40SH |
| Bore size | Ø50 mm |
| Stroke | 40 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X40SH carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X40SH produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X40SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×40 | 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 SI50 Standard Cylinder SI50X40SH Is Used
Short-Stroke Clamping
Ideal for holding parts during machining, utilizing the 982 N push force at 0.5 MPa across a fast 40mm travel.
Diversion Gates
Drives short-stroke sorting flaps or stops on conveyor lines, with the Viton -H seal handling ambient heat up to 150 C.
Replacing the Airtac SI50 Standard Cylinder SI50X40SH with the SAI50X40SH
To replace the discontinued SI50X40SH, order the SAI50X40SH. Confirm the ISO 15552 interface, 50mm bore, 40mm stroke, G1/4 port (PT/G/NPT thread), Viton -H high-temp seal, -S magnet, and your mounting accessory (LB, FA, TC, etc.). The SAI drops into existing fixtures without changes. Sizing both ways: this 50mm bore yields 982 N push at 0.5 MPa; stepping down to a 40mm bore gives 628 N, while stepping up to a 63mm bore provides 1559 N. A plain cylinder does not hold load without live air—the cushion only decelerates—so for suspended loads use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variants. The 40mm stroke is short, so side-load rod-bending is minimal.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X40SH
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X40SH FAQ
Yes, the SI50X40SH is discontinued. The direct replacement is the SAI50X40SH. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 40mm stroke, 982 N force, G1/4 port, and mounting interface, but features an upgraded two Y-shaped element piston seal.
The 50mm bore features a G1/4 air port. It delivers a push force of 982 N and a pull force of 825 N at 0.5 MPa. At 0.7 MPa the push force is 1374 N, and the theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X40SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X40SH replacement — usually within 7-8 hours.