Airtac MKJ Adjustable Cylinder MKJ20X40-20
The AirTAC Airtac MKJ Adjustable Cylinder MKJ20X40-20 is a genuine MK multi-mount cylinder (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, 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
- MagnetWithout magnet
- 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 MKJ20X40-20
The MKJ20X40-20 is an AirTAC multi-mount cylinder, a compact square-body actuator that fixes from 6 directions (front, back, left, right, top and bottom) so it can be bolted wherever the machine layout needs it, and mounted side by side with neighbours to save space. This is the adjustable-stroke variant: double acting, 20 mm bore and 40 mm stroke, with an additional 20 mm of adjustable stroke on top of the base stroke. At 0.5 MPa the bore delivers a theoretical push thrust of about 157.1 N, enough for clamping, positioning and stopping duties on light fixtures. Cushioning is a bumper, which absorbs end-of-stroke impact without the plumbing of an air cushion.
This is a genuine AirTAC part. The MK family is the no-rotating series: a fixed rod and plate stop the piston rod from turning, which matters when the load must stay square to the mount. This SKU is supplied without a magnet, exactly as the code shows; add the trailing S if you need magnetic-switch sensing. Dimensions and sizing are per stroke, so contact us and we will confirm them from the datasheet on request.
Airtac MKJ Adjustable Cylinder MKJ20X40-20 Technical Specifications
| Model | Airtac MKJ Adjustable Cylinder MKJ20X40-20 |
|---|---|
| Type | Multi-mount cylinder, adjustable stroke |
| Series | MK (no-rotating) |
| Bore | 20 mm |
| Push thrust @0.5 MPa | 157.1 N |
| Port size | M5x0.8 (PT thread) |
| Magnet | Without magnet |
| 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
Start with the bore: 20 mm gives about 157.1 N theoretical push thrust at 0.5 MPa (the pull side is lower), so size it against the force your clamp or stopper needs. Choose MK rather than MD when the rod must not rotate, since MK adds a no-rotating plate, brass bushing and fixed rod; MD is the standard series where some rotation is acceptable. The MKJ adjustable-stroke design adds a 10, 20 or 30 mm adjustable range on top of the base stroke, so you can fine-tune the effective stroke at setup. This unit is double acting with no magnet and a PT thread; if you need magnetic-switch sensing pick the S version, and a G thread is available. Keep the stroke inside the bore's table (up to 60 mm for bore 20) and remember the compact cover: an over-long stroke is a common mis-selection. Side-load allowances are not quoted here, so route them to us.
Applications
Small-parts clamping
Clamping brackets and covers on assembly benches where the 157.1 N push at 0.5 MPa holds a light part and the no-rotating rod keeps the clamp pad facing the right way.
Jig positioning
Actuating a positioning pin or locator inside a drill or welding jig, with the 20 mm adjustable range letting the fixture builder trim the effective stroke after setup.
Pick-and-place gating
Extending a small gate or stopper across a parts feed track, using side-by-side mounting of compact bodies where full-size tie-rod cylinders will not fit.
FAQ
What does the code MKJ20X40-20 actually specify?
MKJ is the AirTAC MK family in the adjustable-stroke version: no-rotating and double acting. Bore is 20 mm, base stroke is 40 mm, and the -20 adds a 20 mm adjustable range on top. There is no trailing S, so this unit is supplied without a magnet, and the thread is the PT default (a trailing G would mean G thread).
How does the six-way mounting and the bumper cushion affect installation?
The square body fixes from 6 directions (front, back, left, right, top and bottom), so you can mount it from any face and place units side by side to save space, with magnetic-switch slots around the body. Cushioning is a bumper rather than an air cushion. Keep the stroke within the bore's table to respect the short cover, and confirm dimensions and side-load limits from the datasheet before finalising the fixture.