This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X275, 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 SI50X275
The AirTAC Airtac SI50 Standard Cylinder SI50X275 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X275, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X275
- 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 SI50X275
The AirTAC SI50X275 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 275mm stroke. It delivers 982N push and 825N pull at 0.5MPa via a G1/4 port. Because the SI line is end-of-life, you should order the SAI50X275 direct replacement. It shares the exact ISO 15552 mounting interface, M16x1.5 rod thread and 30mm cushions, dropping straight into existing fixtures.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. Note this non-magnet SKU cannot fit a sensor. If you need load holding on air loss, explore the SAIL lock or BSAI clamp-lock variants, as standard cushions only decelerate.
Airtac SI50 Standard Cylinder SI50X275 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X275 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X275 |
| Bore size | Ø50 mm |
| Stroke | 275 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 SAI50X275 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 SAI50X275 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 SI50X275
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×275 | 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 SI50X275 Is Used
Package Diverting
Actuates routing gates on packaging lines where the 982N thrust easily redirects standard cartons over a 275mm travel distance.
Clamp Actuation
Provides reliable clamping force for mid-weight machining fixtures, utilizing the 30mm adjustable cushions to soften end-of-stroke impact.
Replacing the Airtac SI50 Standard Cylinder SI50X275 with the SAI50X275
To replace the discontinued SI50X275, order the SAI50X275. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port, and the 275mm stroke. Because this SKU lacks the -S magnet, it cannot accept CS1-B/DS1-B sensors; order an -S version if position feedback is required. Sizing both ways: the 50mm bore yields 982N push at 0.5MPa, sitting between the 40mm (628N) and 63mm (1559N) bores. For the 275mm stroke, ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X275
- ✓ 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 SI50X275 FAQ
Yes, the AirTAC SI50X275 is discontinued. The direct replacement is the SAI50X275. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 275mm stroke, output force, G1/4 port, and mounting interface. The SAI simply upgrades the piston seal.
The 50mm bore features a G1/4 air port and an M16x1.5 rod thread. Force output is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, with a theoretical maximum of 200kgf at 1.0MPa. Operating speed is 30-800 mm/s.
Request a Quote for the SAI50X275
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X275 replacement — usually within 7-8 hours.