This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X650LB, 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 SI125X650LB
The AirTAC SI125 Standard Cylinder SI125X650LB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 650mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X650LB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke650 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X650LB
- 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 SI125X650LB
The AirTAC SI125X650LB is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 650 mm stroke. Delivering 6136 N push force at 0.5 MPa via a G1/2 port, it is replaced by the SAI125X650LB. This direct upgrade shares the exact same ISO 15552 mounting interface, bore, stroke, force, port and LB foot mount.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU lacks a magnet so it cannot take a sensor; legacy CS1-B/DS1-B switches only fit -S models. For high heat, Viton H seals raise the limit to 150 C.
Airtac SI125 Standard Cylinder SI125X650LB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X650LB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X650LB |
| Bore size | Ø125 mm |
| Stroke | 650 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 SAI125X650LB 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 SAI125X650LB 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 SI125X650LB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×650 | 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 SI125X650LB Is Used
Heavy Press Clamping
Secures large steel plates in a hydraulic press fixture, utilizing the 6136 N push force to lock components firmly before machining operations begin.
Pallet Lift Gates
Actuates heavy loading dock gates over the 650 mm travel, requiring external linear guides to prevent rod bending under substantial pallet weights.
Replacing the Airtac SI125 Standard Cylinder SI125X650LB with the SAI125X650LB
To replace the SI125X650LB, order the SAI125X650LB. Confirm the ISO 15552 LB foot mount, 650 mm stroke, G1/2 port (PT/G/NPT thread options), and M27x2 rod thread. This non-magnet SKU cannot accept a sensor; if position detection is needed, specify an SAI with the -S magnet. Sizing both ways: a 100 mm bore yields 3927 N [email protected], while a 160 mm bore yields 10053 N. At 650 mm, prevent rod bending by using an external guide to absorb side loads. The standard cylinder does not hold load without air; use an external pilot check valve or the SAIL/BSAI lock variants for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X650LB
- ✓ 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 SI125X650LB FAQ
Yes, the SI125X650LB is discontinued. The direct replacement is the SAI125X650LB. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 650 mm stroke, G1/2 port, force, and LB foot mounting interface.
The G1/2 port bore delivers a push force of 6136 N and pull of 5734 N at 0.5 MPa. At 0.7 MPa push is 8590 N, and 11045 N at 0.9 MPa. The theoretical max force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X650LB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X650LB replacement — usually within 7-8 hours.