Excavator Bucket Couplings: What coupling systems are there?
For an excavator bucket or other attachment to be securely and correctly connected to an excavator, the right excavator coupling must be available. Different coupling systems are used depending on the machine, quick coupler, and application area.
Common variants include the classic direct pin mounting and various quick coupler systems. At Heinz Baumaschinen, you will find attachments suitable for various MS and CW systems, among others.
What excavator bucket couplings are available?
Fundamentally, a distinction can be made between direct mounting of an attachment with pins and the use of a quick coupler. Furthermore, there are different quick coupler systems from various manufacturers and designs.
1. Pin Coupling / Direct Mounting
With direct mounting, the excavator bucket is connected directly to the bucket stick or the corresponding linkage of the excavator using pins. A separate quick coupler is not required here.
To select a suitable attachment, the relevant dimensions of the existing pin coupling must be considered. Since these can vary depending on the machine, the coupling should be precisely measured before ordering.
2. MS Quick Coupler Systems
MS couplings are used on excavators and mini excavators of various weight classes. Well-known sizes include:
- MS01
- MS03
- MS08
- MS10
- MS21
The individual sizes differ, among other things, in pin diameter, internal width of the coupling, and the intended machine class.
We have summarized the exact reference dimensions and differences in a separate guide:
→ MS01, MS03, MS08, MS10 & MS21 – Dimensions and Differences
3. CW Quick Coupler Systems
Another group is CW couplings. Common sizes include, among others:
- CW05
- CW10
- CW20
- CW30
- CW40
For an initial classification of a CW coupling, the pin diameter and the pin spacing from center to center can be used, among other things.
Important: CW20, CW30, and CW40, in particular, cannot always be clearly distinguished from each other based on these two measurements. In such cases, further characteristics and dimensions of the coupling must be considered.
Further information can be found in our detailed CW guide:
→ CW05, CW10, CW20, CW30 & CW40 – Dimensions and Differences
Other Excavator Coupling Systems
In addition to pin couplings and the well-known MS and CW systems, there are other quick couplers and coupling systems for excavators. These include systems from OilQuick, Liebherr, and Martin, among others.
Which coupling system is installed on an excavator cannot always be determined solely by the manufacturer, model, or machine weight. The actually mounted quick coupler is decisive.
OilQuick Couplings
OilQuick offers quick coupler systems for excavators and other construction machinery. Depending on the system, in addition to the mechanical connection, hydraulic connections can also be coupled when changing an attachment.
OilQuick systems are available in various sizes and designs. Therefore, before selecting an excavator bucket or attachment, the exact existing coupling must be determined.
Liebherr Couplings
Different coupling variants are also used on Liebherr excavators and quick couplers.
The excavator's designation alone is therefore not sufficient to clearly select a suitable excavator bucket. The actually installed coupling and its technical design are decisive.
Martin Quick Couplers
Martin quick coupler systems are also used on various excavators. Here, too, different sizes and designs exist.
Before ordering an attachment, it should therefore be checked which Martin system is actually mounted on the excavator.
Other Excavator Couplings and Special Couplings
In addition to MS, CW, OilQuick, Liebherr, and Martin, there are other quick coupler systems, direct couplings, and manufacturer-specific solutions. The selection of an attachment should therefore always be based on the actually existing coupling.
If your coupling is not included in our Coupling Finder, it is best to send us photos of the coupling and the relevant measurements. We will help you with the classification.
→ Inquire about other excavator couplings at Heinz Baumaschinen
What excavator coupling do I have?
The excavator model alone is not always sufficient to clearly determine the existing coupling. Depending on the year of manufacture, equipment, or retrofitted quick coupler, different systems may be installed.
Therefore, we recommend measuring the existing coupling directly. With our Coupling Finder, you can narrow down your coupling based on a few measurements.
→ Determine excavator coupling now with the Coupling Finder
A detailed explanation of how to determine it can also be found here:
→ Which excavator coupling do I have?
Why is the correct coupling important for the excavator bucket?
The coupling establishes the connection between the excavator or quick coupler and the attachment. Therefore, before ordering, it should be checked whether the coupling shape and dimensions of the desired attachment match the existing coupling.
This applies not only to digging buckets, but also, for example, to screening buckets, hydraulic grading buckets, rippers, and root rakes.
Can I select the appropriate coupling based on the excavator size?
The weight class of the excavator can provide an initial indication, but it is not sufficient for a reliable classification. Overlaps between different coupling sizes are possible, and an excavator may be equipped with a different or retrofitted quick coupler.
Therefore, the actually installed coupling, its shape, and its dimensions are decisive.
Which coupling do I need for a digging bucket?
A new digging bucket must match the existing coupling of your excavator or quick coupler. Therefore, first determine your coupling and then select a correspondingly designed digging bucket.
→ View digging buckets for excavators & mini excavators
What to do if I don't know my excavator coupling?
If you cannot clearly determine your coupling, first use our Coupling Finder. If the measured values cannot be clearly assigned, we will be happy to help you.
It is best to send us photos of the coupling and the measured dimensions. This way, we can together check which coupling is present and which attachment fits it.
Conclusion: First determine the coupling, then select the attachment
Whether direct mounting, MS, CW, or another quick coupler system: Before purchasing an excavator bucket or other attachment, the existing coupling should be clearly determined.
Do not rely solely on the manufacturer, excavator model, or weight class, but check the actual coupling and its dimensions.
The easiest way to start is with our Coupling Finder.
Brand notice: Lehnhoff, Verachtert, OilQuick, Liebherr and Martin as well as the named system and product designations are trademarks or designations of their respective rights holders. The named brands and designations are used exclusively for the identification, assignment and description of coupling systems and their compatibility. Heinz Baumaschinen has no business relationship with the respective brand owners. Unless expressly stated otherwise, the attachments offered are not original products of the named brand manufacturers.
