This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X35H, 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 SI125 Standard Cylinder SI125X35H
The AirTAC SI125 Standard Cylinder SI125X35H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 35mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X35H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke35 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X35H
- 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 SI125 Standard Cylinder SI125X35H
The AirTAC SI125X35H is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore, 35 mm stroke, and Viton H high-temperature seals (0 to 150 C). Delivering 6136 N push force at 0.5 MPa via a G1/2 port, it is replaced by the SAI125X35H. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, force, port, and M27x2 rod thread.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet (-S) and cannot accept CS1-B/DS1-B sensors. The SAI family also introduces SAIL and BSAI lock variants absent in the legacy SI line.
Airtac SI125 Standard Cylinder SI125X35H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X35H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X35H |
| Bore size | Ø125 mm |
| Stroke | 35 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| 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 – 500 mm/s |
| Cushion | Adjustable, 40 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X35H carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 kgf | |
The SAI125X35H produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X35H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×35 | 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 SI125 Standard Cylinder SI125X35H Is Used
High-Temp Clamping
Ideal for securing heavy steel components in hot stamping presses where Viton H seals survive 150 C ambient heat and 6136 N force ensures rigid hold.
Aluminum Extrusion
Short-stroke 35 mm actuation for heavy-duty cutoff presses, utilizing the 32 mm rod and M27x2 thread to shear thick profiles reliably.
Pallet Brake Stops
Robust 125 mm bore stopping mechanism for heavy-loaded pallet conveyors, absorbing impact with 40 mm adjustable air cushions at both ends.
Replacing the Airtac SI125 Standard Cylinder SI125X35H with the SAI125X35H
To replace the discontinued SI125X35H, order the SAI125X35H. It is a direct per the ISO 15552 mounting interface, preserving the 125 mm bore, 35 mm stroke, G1/2 port, and Viton H seals. Because this specific SKU lacks a magnet, it cannot support position sensing; if detection is needed, specify an SAI125X35HS. When sizing both ways, neighboring bores (100 mm or 160 mm) offer different force classes, but this 125 mm bore yields a theoretical maximum of 1251 kgf at 1.0 MPa. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X35H
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X35H FAQ
Yes, the SI125X35H is discontinued. The direct replacement is the SAI125X35H. It shares the identical ISO 15552 mounting interface, 125 mm bore, 35 mm stroke, G1/2 port, and Viton H seals, fitting existing fixtures perfectly.
The G1/2 port bore delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s, with a 32 mm rod and 40 mm adjustable cushions.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X35H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X35H replacement — usually within 7-8 hours.