This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement B04-SAID50X250S, 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 B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S
The AirTAC B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the B04-SAID50X250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → B04-SAID50X250S
- 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 B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S
The AirTAC B04-SID50X250S is a double-rod ISO 15552 cylinder where the B04- prefix marks it as a construction-machinery dedicated variant, mechanically identical to the standard SID50X250S. A rod exits both ends on one piston, meaning both faces use the rod-side area and push/pull force is equal at 825 N @0.5 MPa, 1154 N @0.7 MPa, and 1484 N @0.9 MPa. It features a 50 mm bore, G1/4 air port, M16x1.5 rod thread, and 30 mm adjustable cushions at each end. This legacy model is discontinued and the direct replacement is the SAID50X250S.
The SAI replacement family introduces an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and long life, while reusing the exact ISO 15552 mounting interface. The double-rod design provides anti-rotation stability and allows the back rod to carry a sensor cam. Note that air cushions only decelerate near stroke end; for held loads, use an external rod lock or SAIL/BSAI variant.
Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S Technical Specifications
| Model | Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | B04-SAID50X250S |
| Bore size | Ø50 mm |
| Stroke | 250 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 B04-SAID50X250S 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 B04-SAID50X250S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×250 | 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 B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S Is Used
Excavator Linkage Actuation
Drives synchronized positioning arms on heavy equipment where equal push and pull force is required to handle structural loads safely in both directions.
Loader Attachment Shift
Provides anti-rotation stability for moving dual attachments or forks simultaneously, ensuring parallel movement without torsional deflection.
Crusher Tool Drive
Powers opposing tooling on a single piston for material crushing or compacting tasks on construction sites, utilizing the back rod for external cam tracking.
Replacing the Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S with the B04-SAID50X250S
To replace the discontinued B04-SID50X250S, specify the SAID50X250S, which matches the 50 mm bore, 250 mm stroke, G1/4 port, and ISO 15552 mounting dimensions exactly. When sizing both ways, verify your application requires equal force in both directions (825 N @0.5 MPa); if more thrust is needed, step up to the 63 mm bore, or drop to the 40 mm bore if less is required. A double-rod cylinder is the right choice when you need anti-rotation stability or want to drive two tools simultaneously from one piston. Mounting options include Basic, FA, LB, and TC brackets. The -S suffix indicates a built-in piston magnet for legacy CS1-B/DS1-B switches. For strokes of 300 mm or longer, carefully manage side-load alignment to prevent premature seal wear.
Replacement checklist
- ✓ Same ISO 15552 interface → B04-SAID50X250S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID50X250S FAQ
Yes, the B04-SID50X250S is discontinued. The direct replacement is the SAID50X250S. The B04- prefix simply marks it as a construction-machinery dedicated variant of the base SID50X250S, so the SAID replacement shares the exact same 50 mm bore, 250 mm stroke, G1/4 port, and ISO 15552 mounting interface.
Because it is a double-rod cylinder, force is equal both ways at 825 N @0.5 MPa, 1154 N @0.7 MPa, and 1484 N @0.9 MPa. Operating pressure is 0.15-1.0 MPa with a proof pressure of 1.5 MPa. Speed ranges from 30-800 mm/s. Note that air cushions only decelerate the load near stroke end; for load holding on air loss, an external rod lock or SAIL/BSAI variant is required.
Related AirTAC SAI Cylinders
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