This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X185H, 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 SI125X185H
The AirTAC SI125 Standard Cylinder SI125X185H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 185mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X185H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke185 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X185H
- 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 SI125X185H
The AirTAC SI125X185H is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore and 185 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. The direct replacement is the SAI125X185H, which maintains the exact same ISO 15552 mounting interface, bore, stroke, output force, and port size. This Viton H (FKM) seal variant extends the operating temperature range from 0 to 150 C.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For this non-magnet SKU, position sensing via CS1-B or DS1-B switches is not possible.
Airtac SI125 Standard Cylinder SI125X185H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X185H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X185H |
| Bore size | Ø125 mm |
| Stroke | 185 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 SAI125X185H 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 SAI125X185H 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 SI125X185H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×185 | 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 SI125X185H Is Used
Heavy Stamping Press
Drives large platens in metal forming presses where the 6136 N push force at 0.5 MPa is required to shape thick steel blanks.
Injection Mold Actuation
Operates heavy mold cores and ejector pins in high-temperature environments using the Viton H seal rated for 0 to 150 C.
Replacing the Airtac SI125 Standard Cylinder SI125X185H with the SAI125X185H
To replace the SI125X185H, order the SAI125X185H and verify the ISO 15552 mounting interface, 125 mm bore, 185 mm stroke, G1/2 port, and your specific mounting accessory. Sizing checks: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. Note that this non-magnet SKU cannot accept a sensor; if sensing is required, order an SAI variant with the magnet option. Because this is a plain double-acting cylinder, it will not hold a load on air loss—the 40 mm adjustable air cushions only decelerate near stroke end. For load holding, consider an external pilot check valve, rod lock, or the SAIL and BSAI lock variants. The SAI family also includes the SAIF self-valve option, though that is limited to bores 32-100. With a 185 mm stroke, standard mounting is straightforward, but always ensure rigid guidance to prevent rod bending under heavy 313 kg vertical loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X185H
- ✓ 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 SI125X185H FAQ
Yes, the SI125X185H is discontinued. The direct replacement is the SAI125X185H. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 185 mm stroke, output force, G1/2 port, and mounting interface.
This double-acting cylinder features a G1/2 air port and a 32 mm piston rod. It delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X185H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X185H replacement — usually within 7-8 hours.