This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAID40X255, 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 SID Series Double-Rod Cylinder SID40X255
The AirTAC Airtac SID Series Double-Rod Cylinder SID40X255 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 255mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAID40X255, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke255 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAID40X255
- 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 SID Series Double-Rod Cylinder SID40X255
The AirTAC SID40X255 is a double-acting, double-rod ISO 15552 cylinder where a rod exits both ends on one piston. Both faces use the rod-side area, making push and pull force equal at 528 N @0.5 MPa, 739 N @0.7 MPa, and 950 N @0.9 MPa. The bore is 40 mm, the piston rod is Ø16 mm with an M12x1.25 thread, and the air port is G1/4. This SKU has no -S magnet and cannot take a magnetic switch. The SID series is discontinued and directly replaced by the SAID40X255.
The SAID40X255 direct keeps the exact ISO 15552 mounting interface, stroke, and porting, but adds an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants the SI line lacked. A plain cylinder drifts on air loss; the 27 mm adjustable cushion only decelerates near stroke end and never locks.
Airtac SID Series Double-Rod Cylinder SID40X255 Technical Specifications
| Model | Airtac SID Series Double-Rod Cylinder SID40X255 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAID40X255 |
| Bore size | Ø40 mm |
| Stroke | 255 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAID40X255 carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAID40X255 produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SID Series Double-Rod Cylinder SID40X255
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×255 | 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 SID Series Double-Rod Cylinder SID40X255 Is Used
Synchronized Tool Driving
Drives two opposing tools from one piston with equal 528 N force both ways, ensuring perfectly synchronized machining or forming without phase lag.
Anti-Rotation Transfer
The dual-rod geometry resists torsional twist during horizontal transfer, maintaining precise alignment for parts moving at 30-800 mm/s.
Replacing the Airtac SID Series Double-Rod Cylinder SID40X255 with the SAID40X255
To replace the discontinued SID40X255, swap in the SAID40X255 directly—it preserves the G1/4 port, 255 mm stroke, and ISO 15552 mounting holes for FA, LB, or TC brackets without machining. Because force is equal both ways, size it by checking neighbouring bores against the 528 N @0.5 MPa baseline; if you need more push/pull, step up to the 50 mm bore (825 N). Choose a double-rod cylinder when you need anti-rotation stability or must drive two tools from one piston. This non-magnetic SKU cannot use sensors; if you need position feedback, select a -S magnet model. For this 255 mm stroke, ensure your side-load line stays within the manufacturer's allowable offset to prevent guide wear. For load holding on air loss, use an external rod lock or pilot-operated check valve, as cushions do not brake.
Replacement checklist
- ✓ Same ISO 15552 interface → SAID40X255
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SID Series Double-Rod Cylinder SID40X255 FAQ
Yes, the SID40X255 is discontinued. The direct replacement is the SAID40X255. It shares the same ISO 15552 mounting interface, 40 mm bore, 255 mm stroke, G1/4 port, and equal both-ways force, but features an upgraded piston seal.
The G1/4 port feeds a 40 mm bore with a Ø16 mm rod. Because it is double-rod, push and pull force are equal both ways: 528 N @0.5 MPa, 739 N @0.7 MPa, and 950 N @0.9 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAID40X255
Send us the quantity and destination. We confirm price, stock and lead time on the SAID40X255 replacement — usually within 7-8 hours.