This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX145, 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 SI125BX145
The AirTAC SI125 Standard Cylinder SI125BX145 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 145mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX145, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke145 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX145
- 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 SI125BX145
The AirTAC SI125BX145 is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless steel piston rod and a 145 mm stroke. Delivering 6136 N push force at 0.5 MPa, it is replaced by the SAI125BX145 direct, which retains the exact G1/2 port, M27x2 thread, and mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B switches.
Airtac SI125 Standard Cylinder SI125BX145 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX145 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX145 |
| Bore size | Ø125 mm |
| Stroke | 145 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 SAI125BX145 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 SAI125BX145 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 SI125BX145
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×145 | 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 SI125BX145 Is Used
Heavy Press Clamping
Secures large metal workpieces in machining fixtures, using the 6136 N push force at 0.5 MPa to prevent movement during heavy milling.
Corrosive Wash Systems
Actuates doors and mechanisms in chemical wash bays, leveraging the SUS304 stainless rod to resist rust and moisture ingress.
Replacing the Airtac SI125 Standard Cylinder SI125BX145 with the SAI125BX145
To replace the SI125BX145, order the SAI125BX145, confirming the ISO 15552 mounting interface, 125 mm bore, 145 mm stroke, G1/2 port, and SUS304 rod. Sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. If your stroke exceeds 300 mm, add external guides to prevent rod bending. This plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX145
- ✓ 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 SI125BX145 FAQ
Yes, the SI125BX145 is discontinued. The direct replacement is the SAI125BX145. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 145 mm stroke, G1/2 port, and mounting fixtures.
It features a G1/2 port. Force ratings are: 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 max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX145
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX145 replacement — usually within 7-8 hours.