This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the drop-in replacement SAI40X125SCB, 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.
The AirTAC Airtac SI ISO Cylinders SI40X125SCB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the drop-in replacement is the SAI40X125SCB, which matches its ISO interface, bore, stroke, force and mounting.
The AirTAC SI40X125SCB is a discontinued double-acting ISO 15552 profile cylinder - extruded aluminium barrel, 16 mm rod, M12x1.25 rod thread, G1/4 air port and a 27 mm adjustable cushion at each end - with a 40 mm bore and 125 mm stroke. At 0.5 MPa it pushes 628 N and pulls 528 N, rising to 879 N at 0.7 MPa, and its built-in piston magnet pairs with the legacy CS1-B/DS1-B switch set. The CB clevis rear mount is part of the standard ISO 15552 accessory interface. This SI model is end-of-life: order the SAI40X125SCB instead, a true drop-in that keeps the same ISO 15552 mounting interface, bore, stroke, force, port size and accessories, so it fits your existing fixture unchanged.
The SAI40X125SCB is not just a like-for-like swap - it is the current-production upgrade. Its piston seal uses two Y-shaped one-way elements for long life and low start-up pressure, and the SAI family adds variants the SI line never offered: SAIL (air-released lock), SAIF (built-in 4M valve, bores 32-100) and BSAI (clamp-lock). Ratings and interface are unchanged. For sizing, treat 628 N as the working figure: keep continuous load near 377 N (about 60% of push at 0.5 MPa), and for vertical lifting that is roughly 32 kg with a 2:1 margin. Speed range is 30-800 mm/s, operating pressure 0.15-1.0 MPa with 1.5 MPa proof, and -20 to +70 C temperature (Viton H seals raise this to 0-150 C).
| Model | Airtac SI ISO Cylinders SI40X125SCB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X125SCB |
| Bore size | Ø40 mm |
| Stroke | 125 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 SAI40X125SCB carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X125SCB 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.
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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).
A 40 mm bore delivering 628 N push at 0.5 MPa (879 N at 0.7 MPa) suits light clamping and press-fit stations. Keep continuous clamping force near 377 N for margin, and specify the SAIL or BSAI lock variant if the fixture must stay clamped on air loss.
With a 125 mm stroke and 30-800 mm/s speed, the cylinder pushes cartons or trays sideways off a conveyor line. The CB rear clevis lets the rod stroke pivot naturally through the divert arc, and the -S magnet gives end-position sensing with current AirTAC switches.
The 528 N pull at 0.5 MPa handles part transfer slides and gripper arms on compact assembly stations. The ISO 15552 profile body with sensor groove keeps switch mounting tidy, and the SAI40X125SCB drop-in means the cell fixture needs no re-machining.
To replace your SI40X125SCB, order the SAI40X125SCB - insert the A after the leading S and keep everything else: 40 mm bore, 125 mm stroke, magnet S and CB clevis mount. Confirm the ISO 15552 interface first (it is unchanged), then check the port style: PT thread as standard, with G and NPT (code T) options - the port size itself is fixed by the bore at G1/4. Size both ways: if 628 N push at 0.5 MPa is marginal, step up to the 50 bore (982 N); if it is generous, the 32 bore (402 N) may suffice - but note the SAI40X125SCB keeps your existing fixture, so changing bore means new mountings. Remember a plain cylinder does not hold load on air loss: the cushion only decelerates near stroke end, it is never a lock. For a held load add an external rod lock or pilot-operated check valve, or step to the SAIL (air-released lock) or BSAI (clamp-lock) variant; if you want valve integration, the SAIF with built-in 4M valve covers bores 32-100. The -S magnet works with current AirTAC switches on the SAI, replacing the legacy CS1-B/DS1-B set.
Replacement checklist
Yes, the SI40X125SCB is discontinued. The replacement is the SAI40X125SCB - insert an A after the leading S. It is a drop-in swap with the same ISO 15552 mounting interface, 40 mm bore, 125 mm stroke, 628 N push force, G1/4 port and CB clevis mounting, so it fits your existing fixture without modification. The SAI adds an upgraded two-element Y piston seal and new lock and valve variants.
At 0.5 MPa: 628 N push and 528 N pull. At 0.7 MPa: 879 N push, and 1130 N push at 0.9 MPa. The theoretical maximum is 128 kgf at 1.0 MPa. Practical guidance: size continuous loads at about 377 N (60% of the 0.5 MPa push figure), which supports roughly 32 kg in vertical lifting with a 2:1 margin. Operating pressure is 0.15-1.0 MPa with 1.5 MPa proof, and the rod is 16 mm with an M12x1.25 thread.
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X125SCB replacement — usually within 7-8 hours.