Airtac MKJ Adjustable Cylinder MKJ20X40-40S
The AirTAC MKJ Adjustable Cylinder MKJ20X40-40S is a genuine MK multi-mount cylinder (double rod, adjustable stroke), 20 mm bore. Its compact square body fixes from six directions and mounts side by side to save space. It delivers about 157.1 N of push force at 0.5 MPa. A bumper cushions the impact. As an MK unit a fixed rod stops the piston rod rotating.
- TypeMulti-mount, double rod, adjustable stroke
- SeriesMK (no-rotating)
- Bore20 mm
- Push thrust @0.5 MPa157.1 N
- Operating pressure0.15 - 1.0 MPa (22 - 145 psi)
- Port sizeM5x0.8
- CushionBumper
- MagnetWith magnet (sensor-ready)
- ThreadPT
- 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 MKJ Adjustable Cylinder MKJ20X40-40S
The MKJ20X40-40S is an AirTAC MKJ no-rotating adjustable-stroke multi-mount cylinder with a 20 mm bore and a 40 mm base stroke plus the adjustable range coded after the hyphen. The square body fixes from six directions (front, back, left, right, top and bottom) and mounts side by side to save space.
This is a genuine AirTAC part. Unlike the standard MD family, the MK family adds a no-rotating plate, brass bushing and fixed rod so the rod cannot turn - useful wherever a clamp pad or plate must hold its angle. The trailing S on this SKU means it is supplied with a magnet for switch detection in the slots around the body. Materials are typically aluminium alloy, stainless or S45C rod and NBR seals, and we confirm the exact adjustable range and dimensions from the datasheet on request.
Airtac MKJ Adjustable Cylinder MKJ20X40-40S Technical Specifications
| Model | Airtac MKJ Adjustable Cylinder MKJ20X40-40S |
|---|---|
| Type | Multi-mount cylinder, double rod, adjustable stroke |
| Series | MK (no-rotating) |
| Bore | 20 mm |
| Push thrust @0.5 MPa | 157.1 N |
| Port size | M5x0.8 (PT thread) |
| Magnet | With magnet (S) |
| Fluid | Air, filtered to 40 um |
|---|---|
| Operating pressure | 0.15 - 1.0 MPa (22 - 145 psi) |
| Proof pressure | 1.5 MPa (215 psi) |
| Temperature | -20 to 70 C |
| Speed range | 30 - 500 mm/s |
| Cushion | Bumper |
| Mounting | Fix from 6 directions; mountable side by side |
Specifications follow the official AirTAC MD/MK multi-mount data. The front cover and piston are short, so avoid an over-long stroke. An optional high-temperature seal material extends the range to 0 to 150 C. Overall dimensions vary per stroke and allowable side-load is published as curves — ask us and we confirm from the datasheet.
How to choose
MK prevents rod rotation; MD allows it. Acting options are double (MK), single push (MSK), single pull (MTK), double rod (MKD) and adjustable stroke (MKJ), whose standard adjustable ranges are 10, 20 or 30 mm - this SKU is coded -40, so we confirm its exact adjustable range from the datasheet. This version includes the magnet (S) and uses PT thread, with G available. Keep the stroke reasonable for the short cover, and route side-load questions to us, as those figures live in the datasheet.
Applications
Slide clamping on fixtures
Drives a sliding clamp jaw across small workpieces; the no-rotating rod keeps the jaw aligned, and several cylinders mount side by side on one plate.
Lift-and-locate pin
Raises a locating pin under a machined plate at a fixture station; the no-rotating rod stops the pin from turning as it lifts and drops.
Ejecting parts from nests
Ejects small finished parts out of a die or nest on a production line; the compact body fits where space is tight, fixed from any of six faces.
FAQ
How do I choose between MDJ and MKJ for an adjustable stroke?
The difference is rotation: MDJ lets the rod turn, while MKJ (this model) fits a no-rotating plate, brass bushing and fixed rod so the rod holds its orientation. Choose MKJ when attached pads or plates must not spin.
Is there a stroke limit I should watch for the 20 mm bore?
Double-acting strokes for the 20 mm bore run up to 60 mm, and this SKU's 40 mm base stroke sits inside that. The short cover means an over-long stroke is cautioned against, and allowable side load plus overall dimensions come from the datasheet, which we can confirm on request.