This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X165STC, 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 SI50X165STC
The AirTAC Airtac SI50 Standard Cylinder SI50X165STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 165mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X165STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke165 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X165STC
- 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 SI50X165STC
The AirTAC SI50X165STC is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 165 mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50X165STC, which shares the exact ISO 15552 mounting interface, TC trunnion accessory, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding on air loss, the SAI family introduces SAIL and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50X165STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X165STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X165STC |
| Bore size | Ø50 mm |
| Stroke | 165 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 SAI50X165STC 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 SAI50X165STC 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 SI50X165STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×165 | 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 SI50X165STC Is Used
Package Diversion
Actuates routing gates on packaging lines, utilizing the 982 N push force to reliably redirect cartons up to 50 kg at operating speeds up to 800 mm/s.
Clamp Actuation
Provides repeatable clamping pressure for machining fixtures, with the TC trunnion mount accommodating slight alignment shifts during the 165 mm travel.
Replacing the Airtac SI50 Standard Cylinder SI50X165STC with the SAI50X165STC
To replace the SI50X165STC, order the SAI50X165STC. Confirm the ISO 15552 interface, 50 mm bore, 165 mm stroke, G1/4 port (PT/G/NPT thread options), TC trunnion mounting, and the -S magnet for CS1-B/DS1-B switches. If sizing up or down, neighboring bores 40 mm and 63 mm offer 628 N and 1559 N push at 0.5 MPa respectively. Note that a plain cylinder drifts on air loss; the air cushion only decelerates near stroke end. For secure load holding, specify an external pilot check valve or the SAIL/BSAI lock variant. Since the stroke is under 300 mm, side-load rod-bending risks are minimal, but always verify guide alignment.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X165STC
- ✓ 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 SI50X165STC FAQ
Yes, the AirTAC SI50X165STC is discontinued. The direct replacement is the SAI50X165STC. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 165 mm stroke, G1/4 port, TC mounting, and force ratings to fit existing fixtures.
This double-acting cylinder has 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, 1767 N push at 0.9 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X165STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X165STC replacement — usually within 7-8 hours.