Bürkle Mole Drill Head Combination, interchangeable head for soil sampler, iron/steel, 5350-1030

Not every site has the same soil type throughout. If a plot alternates between cohesive, clayey sections and looser, less cohesive areas, the head would have to be changed every time the soil type changes unless there is a ‘generalist’ among the drill heads. The Mole Combination drill head is designed for this mixed situation and covers both highly and weakly cohesive soils in a single head.

One head for two properties

Whilst specialised drill heads for clay, sand or coarse sand are each tailored to a single soil type, this drill head combines features that work equally well in both highly cohesive material and less cohesive soil. This makes it a practical choice when the soil type at the site is not known for certain in advance or varies within the area to be investigated, without the need to carry a separate, highly specialised head for each survey.

When a specialised head is still worthwhile

A combination head is a compromise and is therefore slightly less optimised for each individual soil type than the respective specialised head. If it is clear from the outset that a site consists entirely of a single, clearly identifiable soil type, such as pure clay or pure sand, the appropriate specialised head will generally deliver the better result. The combination head is particularly useful where this prior knowledge is lacking, or where, for reasons of space and weight, only one head can be taken along.

Use with the Mole handle

This drill head is also purely an interchangeable part for the ‘Mole’ handle with shaft and cannot be used on its own. The handle is 750 millimetres long; for greater drilling depths, it can be extended using a 100-centimetre extension (5350-1010) without having to replace the handle itself.

Typical applications

The combination head is called for whenever the soil type across an area is not uniformly consistent or cannot be precisely determined in advance, for example in:

• Soil mapping on sites with varying soil conditions
• Preliminary investigations where the exact soil type at the site is not yet known
• Site investigation on heterogeneous plots
• Fieldwork where only one drill head is to be carried

Comparison with specialised heads

If the soil at the site is consistently clayey and damp, the specialised ‘Clay and Damp Soils’ drill head, with its narrow flanks, provides better guidance within the borehole. If, on the other hand, the subsoil is recognisably sandy and loose, the ‘Sand’ drill head, with its wider bearing surface, performs more reliably. If it only becomes apparent during the work that the soil is coarser and drier than expected, switching to the coarse sand drill head is the next step.

Material and storage

The combination head is also made of iron/steel, the same material as the handle and all other Mole drill heads. With no electronics or battery, it is ready for immediate use, regardless of how long it has been in storage. To store it between uses, a dry place at room temperature is sufficient, as is the case for the handle and the other heads.

Technical details

Scope of delivery

• Mole Combination drill head

The Mole handle with shaft is not included in the scope of delivery and must be provided separately or ordered at the same time.

Service and procurement

For initial surveys where the soil type is not yet known, the combination head is often recommended as the first choice, before we supply a suitable specialised head if required. If you have any questions regarding the soil type at your own site, please contact us directly for assistance.