This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX135, 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 SI50AX135
The AirTAC Airtac SI50 Standard Cylinder SI50AX135 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 135mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX135, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke135 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX135
- 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 SI50AX135
The AirTAC SI50AX135 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 135mm stroke. It delivers 982 N push force at 0.5 MPa, uses a G1/4 port, and features a SUS420J2 stainless steel rod. The direct replacement is the SAI50AX135, which shares identical ISO 15552 mounting dimensions, output force, and port size.
Because this specific SKU lacks the -S magnet suffix, it cannot accept a position sensor. The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life.
Airtac SI50 Standard Cylinder SI50AX135 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX135 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX135 |
| Bore size | Ø50 mm |
| Stroke | 135 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 SAI50AX135 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 SAI50AX135 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 SI50AX135
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×135 | 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 SI50AX135 Is Used
Package Diverting
Drives diverter arms on packaging lines where the 982 N push force easily handles routing standard cartons at 30-800 mm/s.
Clamp Actuation
Provides reliable clamping pressure for medium-duty CNC machining fixtures, utilizing the SUS420J2 stainless rod for corrosion resistance.
Replacing the Airtac SI50 Standard Cylinder SI50AX135 with the SAI50AX135
To replace the SI50AX135, order the SAI50AX135 to retain the exact ISO 15552 interface, 50mm bore, 135mm stroke, G1/4 port, and M16x1.5 rod thread. Confirm your mounting accessory (LB, FA, TC, etc.) and thread standard (PT, G, NPT) carry over directly. If you need position sensing, you must select an SAI variant with the magnet suffix, as this legacy SKU cannot host a switch. For sizing alternatives, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore provides 1559 N. Note that a standard cylinder drifts on air loss; the air cushion only decelerates the piston near stroke end. For load holding, use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX135
- ✓ 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 SI50AX135 FAQ
Yes, the AirTAC SI50AX135 is discontinued. The direct replacement is the SAI50AX135. It is dimensionally interchangeable per ISO 15552, maintaining the same 50mm bore, 135mm stroke, G1/4 port, and mounting footprint.
This double-acting cylinder uses a G1/4 air port. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX135
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX135 replacement — usually within 7-8 hours.