This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ50X40-20, 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 SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20
The AirTAC SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 40mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ50X40-20, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke40 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAIJ50X40-20
- 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 SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20
The AirTAC SIJ50X40-20 is a discontinued double-acting double-rod ISO 15552 adjustable-stroke cylinder. An external stop screw lets you trim the extend stroke by up to 20 mm on-site, yielding a usable 20-40 mm stroke from the 40 mm nominal maximum. The 50 mm bore uses a G1/4 port, a Ø20 mm rod, and 30 mm adjustable cushions. The direct replacement is the SAIJ50X40-20, which shares the same interface, force, and mounting.
The SAIJ upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. Note this SKU has no -S magnet and cannot support sensing. The external stop sets the end position but is not a load lock; for held loads use an external rod lock or the SAIL/BSAI variants.
Airtac SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 Technical Specifications
| Model | Airtac SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ50X40-20 |
| Bore size | Ø50 mm |
| Stroke | 40 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 SAIJ50X40-20 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 SAIJ50X40-20 produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×40 | 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 SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 Is Used
Short-Stroke Clamping
Ideal for clamping parts where the exact material thickness varies slightly, using the 20 mm on-site adjust window to fine-tune the extend endpoint without moving the fixture.
Diverter Gate Positioning
Adjusts a diverter gate stroke from 40 mm down to 20 mm on-site to accommodate different package sizes on the fly, ensuring precise routing without changing the cylinder.
Sealing Head Travel
Provides a 20-40 mm sealing head stroke for packaging machines, allowing operators to trim the extend position to match varying container heights directly at the machine.
Replacing the Airtac SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 with the SAIJ50X40-20
To replace the discontinued SIJ50X40-20, order the direct replacement SAIJ50X40-20, reusing your existing FA, LB, or TC ISO 15552 mounts. The 20 mm adjust window is ideal if your end-position target varies within a 20-40 mm extend range. Because this SKU lacks the -S magnet, it cannot accept legacy CS1-B/DS1-B sensors; add external proximity sensing if detection is required. For strokes of 300 mm or longer, verify your side-load limits to prevent excessive guide wear. Remember the stop screw only trims travel—it does not hold the load on air loss.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ50X40-20
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SIJ50 Double Rod Adjustable Cylinder SIJ50X40-20 FAQ
Yes, the SIJ50X40-20 is discontinued. The direct replacement is the SAIJ50X40-20, which matches the 50 mm bore, 40 mm stroke, 20 mm adjust window, G1/4 port, and ISO 15552 mounting interface. The SAIJ family also features an upgraded two Y-shaped one-way piston seal for longer life.
The external stop screw allows you to trim the extend stroke by up to 20 mm on-site, giving a usable stroke range of 20-40 mm. The stop sets end position only and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ50X40-20
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ50X40-20 replacement — usually within 7-8 hours.