This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX35, 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 SI50AX35
The AirTAC Airtac SI50 Standard Cylinder SI50AX35 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX35, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX35
- 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 SI50AX35
The AirTAC SI50AX35 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 35mm stroke, delivering 982N push force at 0.5MPa. The direct replacement is the SAI50AX35, matching the bore, stroke, G1/4 port and ISO 15552 mounting interface. This SKU features a SUS420J2 stainless steel rod but lacks a magnet, so it cannot accept a position switch.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. Note that air cushions only decelerate; use a pilot check valve or SAIL lock variant to hold loads.
Airtac SI50 Standard Cylinder SI50AX35 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX35 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX35 |
| Bore size | Ø50 mm |
| Stroke | 35 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 SAI50AX35 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 SAI50AX35 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 SI50AX35
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×35 | 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 SI50AX35 Is Used
Clamping Fixtures
Ideal for securing mid-weight components during machining, utilizing the 982N push force to hold parts firmly against stops.
Package Diverting
Short 35mm stroke acts as a rapid diverter arm on packaging lines, pushing cartons between adjacent belts without overtravel.
Press Insertion
Provides steady downward pressure for seating bearings or pins, taking advantage of the 50kg vertical lift capacity with a safety margin.
Replacing the Airtac SI50 Standard Cylinder SI50AX35 with the SAI50AX35
To replace the SI50AX35, order the SAI50AX35 keeping the identical 50mm bore, 35mm stroke, G1/4 port, M16x1.5 thread and ISO 15552 mounting. Since this SKU has no -S suffix, it lacks a magnet and cannot support CS1-B or DS1-B sensors; if sensing is needed, specify a magnet on the new SAI. For sizing, the 50mm bore yields 982N push at 0.5MPa; dropping to a 40mm bore gives 628N, while a 63mm bore provides 1559N. A plain cylinder drifts without live air, so for load holding select the SAIL or BSAI lock variant, or use an external pilot check valve. The 35mm stroke is short enough to avoid rod-bending side-load concerns.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX35
- ✓ 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 SI50AX35 FAQ
Yes, the AirTAC SI50AX35 is discontinued. The direct replacement is the SAI50AX35. It shares the exact same ISO 15552 mounting interface, 50mm bore, 35mm stroke, output force, G1/4 port, and accessories, fitting seamlessly into existing fixtures.
The 50mm bore operates on a G1/4 air port. It generates 982N push and 825N pull at 0.5 MPa, 1374N push at 0.7 MPa, and 1767N push at 0.9 MPa, with a theoretical maximum of 200 kgf at 1.0 MPa.
Request a Quote for the SAI50AX35
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX35 replacement — usually within 7-8 hours.