This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X70H, 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 SI40 Standard Cylinder SI40X70H
The AirTAC Airtac SI40 Standard Cylinder SI40X70H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X70H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X70H
- 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 SI40 Standard Cylinder SI40X70H
The AirTAC SI40X70H is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 70 mm stroke. It delivers 628 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI40X70H, matching the interface, bore, stroke, force, port and mounting. The SAI upgrades the piston seal to two Y-shaped one-way elements for low start-up pressure and long life. This SI40X70H variant uses a Viton H seal, raising the operating temperature range to 0-150 C. As a non-magnet SKU, it cannot take a sensor.
Because this is a plain cylinder, it will not hold a load if air pressure drops; the 27 mm adjustable air cushions only decelerate the piston near stroke end. For secure load holding, use an external pilot check valve, a rod lock, or the SAI family's SAIL air-released lock or BSAI clamp-lock variants. The SAI family also includes the SAIF variant with a built-in 4M valve (bores 32-100) which the legacy SI lacked.
Airtac SI40 Standard Cylinder SI40X70H Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X70H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X70H |
| Bore size | Ø40 mm |
| Stroke | 70 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 SAI40X70H carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X70H produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X70H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×70 | 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 SI40 Standard Cylinder SI40X70H Is Used
Hot-End Ejection
Uses the Viton H high-temperature seal to push parts out of 0-150 C molding or drying fixtures safely.
Diverting Arm
Cycles at 30-800 mm/s to deflect small packages on a line, matching the 70 mm stroke perfectly.
Pallet Stopper
Provides 628 N push force at 0.5 MPa to halt lightweight pallets without overshooting the target.
Replacing the Airtac SI40 Standard Cylinder SI40X70H with the SAI40X70H
To replace the discontinued SI40X70H, order the SAI40X70H. Verify the ISO 15552 mounting interface dimensions, the 40 mm bore, 70 mm stroke, G1/4 port (PT/G/NPT thread options), and your mounting accessory (LB, FA, FB, CA, CB, TC, etc.). This SKU lacks the -S magnet, so it cannot accept a CS1-B or DS1-B sensor; if position detection is needed, order the SAI equivalent with an S suffix for current AirTAC switches. When sizing both ways, a 32 mm bore offers 402 N push at 0.5 MPa, while a 50 mm bore provides 982 N. The Viton H seal on this unit supports 0-150 C, unlike standard NBR. Remember that a standard cylinder drifts without live air; for load holding, select the SAIL or BSAI lock variant, or add an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X70H
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X70H FAQ
Yes, the SI40X70H is discontinued. The direct replacement is the SAI40X70H. It is dimensionally interchangeable per ISO 15552, keeping the same 40 mm bore, 70 mm stroke, 628 N force, G1/4 port and mounting fixtures.
The bore is 40 mm with a G1/4 air port. At 0.5 MPa it provides 628 N push and 528 N pull force. At 0.7 MPa push is 879 N, and at 0.9 MPa it is 1130 N. The theoretical maximum force is 128 kgf at 1.0 MPa.
Request a Quote for the SAI40X70H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X70H replacement — usually within 7-8 hours.