This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement B04-SAID40X250S, 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-SID40X250S
The AirTAC Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID40X250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the B04-SAID40X250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → B04-SAID40X250S
- 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-SID40X250S
The AirTAC B04-SID40X250S is a double-acting, double-rod ISO 15552 cylinder where the B04- prefix marks it as a construction-machinery dedicated variant, mechanically identical to the standard SID40X250S. Because 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. It features a 16 mm rod, M12x1.25 rod thread, G1/4 port, and 27 mm adjustable cushions. This SID model is discontinued; the direct replacement is the SAID40X250S, sharing the same interface, bore, stroke, and mounting.
The SAID upgrade introduces a two-piece Y-shaped one-way piston seal for lower start-up pressure and longer life. The -S suffix denotes a built-in piston magnet for legacy CS1-B/DS1-B switches. Note that air cushions only decelerate near stroke end; they do not hold loads on air loss, so use an external rod lock or SAIL/BSAI variant for held loads.
Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID40X250S Technical Specifications
| Model | Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID40X250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | B04-SAID40X250S |
| Bore size | Ø40 mm |
| Stroke | 250 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 B04-SAID40X250S 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 B04-SAID40X250S 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-SID40X250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | 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-SID40X250S Is Used
Excavator Linkage Actuation
Drives balanced push-pull mechanisms on heavy equipment with equal force both ways, preventing sag on the return stroke.
Loader Attachment Sync
Uses the rear rod end to mount a sensor cam for position feedback while the front rod shifts a secondary tool simultaneously.
Crusher Tooling Ejection
Ejects processed material from construction machinery hoppers, relying on the anti-rotation property of the double-rod design.
Replacing the Airtac B04-SID Construction Machinery Special ISO Standard Cylinder B04-SID40X250S with the B04-SAID40X250S
To replace the discontinued B04-SID40X250S, specify the SAID40X250S, which reuses the exact ISO 15552 mounting interface and G1/4 port without bracket changes. Choose a double-rod cylinder when you need equal force both ways, anti-rotation stability, or a back rod to carry a sensor cam. You can size both ways by checking neighbor bores (32 mm or 50 mm) against your force requirements. Mounting options include Basic, FA, LB, and TC. The -S magnet supports legacy CS1-B/DS1-B switches. For this 250 mm stroke, side-load alignment is acceptable, but for strokes >=300 mm, carefully calculate guide rod bearing loads.
Replacement checklist
- ✓ Same ISO 15552 interface → B04-SAID40X250S
- ✓ 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-SID40X250S FAQ
Yes, the B04-SID40X250S is discontinued. The direct replacement is the SAID40X250S. The B04- prefix simply marks it as a construction-machinery dedicated variant of the base SID40X250S, so all physical specs like the G1/4 port and 16 mm rod remain identical.
Because it is a double-rod cylinder, force is equal both ways: 528 N @0.5 MPa, 739 N @0.7 MPa, and 950 N @0.9 MPa. Operating speed is 30-800 mm/s. It never quotes a larger single-rod push value.
Related AirTAC SAI Cylinders
Request a Quote for the B04-SAID40X250S
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