This model is discontinued
AirTAC has phased out the MAL series. The drop-in replacement is B04-SAI50X350S — same bore, stroke, output force, port and mounting, so it fits the same application. Simply order the B04-SAI50X350S in place of this model. 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-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S
The AirTAC Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the drop-in replacement is the B04-SAI50X350S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → B04-SAI50X350S
About the Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S
The AirTAC B04-SI50X350S is a discontinued double-acting ISO 15552 profile cylinder. The B04- prefix marks it as the construction-machinery dedicated variant of the base SI50X350S, mechanically identical with 982 N push force at 0.5 MPa, a G1/4 port, and a 350 mm stroke. AirTAC replaced this EOL unit with the SAI50X350S, a true drop-in sharing the exact ISO 15552 mounting interface, bore, output force, and porting.
The SAI upgrade features a modernized piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. For load holding, note that a plain cylinder drifts on air loss—the cushion only decelerates. Use the SAIL lock or BSAI clamp-lock variants if needed. Safe working load is roughly 589 N (about 60% of the 982 N push), allowing a 50 kg vertical lift with a 2:1 margin.
Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S Technical Specifications
| Model | Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | B04-SAI50X350S |
| Bore size | Ø50 mm |
| Stroke | 350 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-SAI50X350S 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-SAI50X350S produces the same force from the same bore — a true drop-in on output. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×350 | 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-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S Is Used
Excavator Actuation
Drives auxiliary mechanisms on heavy equipment where the B04- prefix indicates construction-machinery dedication, fitting within tight ISO 15552 mounting envelopes.
Material Handling Gates
Cycles heavy sorting gates on aggregate or concrete batching plants, utilizing the 982 N push force at 0.5 MPa to move weighted baffles reliably.
Long-Stroke Positioning
Extends 350 mm to push or align construction materials, requiring external guide rails to prevent rod bending under off-center loads.
Replacing the Airtac B04-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S with the B04-SAI50X350S
To replace the B04-SI50X350S, order the SAI50X350S. It drops directly into existing ISO 15552 fixtures with the same 50 mm bore, 350 mm stroke, G1/4 port, and M16x1.5 rod thread. Confirm your mounting accessory (LB, FA, TC, etc.) and retain the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). When sizing, neighboring bores offer different forces: the 40 mm bore provides 628 N push @0.5 MPa, while the 63 mm bore yields 1559 N. For this 350 mm stroke, add external guides to prevent rod bending and side-load wear. Because standard cylinders do not hold load without live air, specify an external pilot check valve or the SAIL/BSAI lock variant for suspended loads.
Replacement checklist
- ✓ Same ISO 15552 interface → B04-SAI50X350S
- ✓ 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-SI Construction Machinery Special ISO Standard Cylinder B04-SI50X350S FAQ
Yes, the B04-SI50X350S is discontinued. The exact drop-in replacement is the SAI50X350S. It shares the identical ISO 15552 mounting interface, 50 mm bore, 350 mm stroke, G1/4 port, and output force. The B04- prefix simply marked it as the construction-machinery dedicated variant, and the SAI replacement matches all physical specs while upgrading the piston seal.
The 50 mm bore uses a G1/4 air port and an M16x1.5 rod thread. Force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
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