This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX85, 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 SI50AX85
The AirTAC Airtac SI50 Standard Cylinder SI50AX85 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 85mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX85, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke85 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX85
- 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 SI50AX85
The AirTAC SI50AX85 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 85mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50AX85, matching the exact ISO 15552 mounting interface, stroke and force.
This SKU lacks a magnet (-S) and cannot accept a sensor. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The -A rod denotes SUS420J2 stainless steel, unlike the default carbon steel.
Airtac SI50 Standard Cylinder SI50AX85 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX85 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX85 |
| Bore size | Ø50 mm |
| Stroke | 85 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 SAI50AX85 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 SAI50AX85 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 SI50AX85
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×85 | 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 SI50AX85 Is Used
Mid-Force Clamping
Secures medium workpieces in CNC machining fixtures, utilizing the 982N push force at 0.5MPa.
Package Diversion
Actuates routing gates on 50mm bore packaging lines where an 85mm stroke moves parcels efficiently.
Replacing the Airtac SI50 Standard Cylinder SI50AX85 with the SAI50AX85
To replace the SI50AX85, order the SAI50AX85. Confirm the ISO 15552 mounting fixture, G1/4 port, M16x1.5 rod thread and 85mm stroke. The -A code specifies the SUS420J2 stainless rod; omit it for standard carbon steel. Since this lacks -S, it cannot hold a magnetic switch. For sizing, neighbouring bores are 40mm (628N push @0.5MPa) and 63mm (1559N push @0.5MPa). A plain cylinder drifts without air; for load holding use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX85
- ✓ 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 SI50AX85 FAQ
Yes, the SI50AX85 is discontinued. The direct replacement is the SAI50AX85, matching the ISO 15552 mounting interface, 50mm bore, 85mm stroke, force and G1/4 port.
It features a G1/4 port. Force ratings are 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a 200kgf max at 1.0MPa.
Request a Quote for the SAI50AX85
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX85 replacement — usually within 7-8 hours.