The different types of Indent crimping:

The indent crimp: for copper and aluminium

The indent crimp is one of the few crimp profiles that require no cross-section-dependant crimping dies. For example, the Klauke EKM 60 ID an process a crimping range of 10-240 mm² for copper and 50-240 mm² for aluminium. This is made possible by two technical innovations. First, the hydraulic cylinder is a single-acting 2-stage telescopic cylinder. Due to the differing piston diameters and the patented design of the two hydraulic cylinders, the crimping head produces twice the force at the start through the larger hydraulic cylinder, than it does at the end when only the smaller hydraulic cylinder is working. Consequently, the larger cross-sections are processed with a greater force than the smaller ones. This guarantees that all cross-sections are crimped with adequate force and smaller cross-sections are not damaged by excessive force. Second, the indent is a special profile, which is matched to the respective diameter of the cross-sections. 

As well as needing fewer dies, this has an added advantage for the user. This crimp profile can be used to process even very thinned-out or compacted conductors. This is because the device switches off only after the required degree of compaction is achieved. This profile is also capable of processing tubular cable lugs, tubular cable lugs for fine and superfine stranded conductors, solderless terminals and aluminium cable lugs. Fine-stranded conductors in tubular cable lugs are also possible.

Tubular cable lugs and aluminium cable lugs require the same number of crimps as wide crimping due to the properties. When processing aluminium cable lugs, it must be ensured that the tool is positioned offset by 180° for every crimp. Otherwise, the aluminium cable lug can become deformed. With solderless terminals, the soldered joint must always be crimped once. With tubular cable lugs for fine-stranded conductors, it is necessary to crimp once up to 185 mm² and twice from 240 mm².

Advantages of indent crimping at a glance:

  • Reliable: it is not possible to mix up or mismatch the dies.
  • Flexible: the crimp profile can be used flexibly for various conductor classes and is especially suitable for thinned-out or compacted conductors.
  • Cost-effective: no additional purchase of dies required.

Klauke's product portfolio:

> Crimping tool EKM 60 ID (10 - 240 mm²)

> Crimping tool EK 120 ID (35 - 500 mm²)

> Crimping head PK 60 ID (10 - 240 mm²) 

The indent crimp: for copper and insulated materials

The indent crimp was developed for producing connections with cable lugs to DIN 46234 and connectors to DIN 46341 Part 1, profiles A+B, which are in turn suitable for mounting Class 2, 5 and 6 conductors to DIN EN 60228. 

To be able to cover all conductor classes without a problem, cable lugs and connectors to these standards have a large internal diameter. Indent crimps deform the individual strands so as to make very good electrical and mechanical contact.

The indent crimp has a cross-section that resembles a halfmoon. This crimp can also be described as deep indent, which allows the conductor strands to move and form a solid compression. Despite the large internal diameter, a permanent, compact and reliable connection can be guaranteed thanks to the centered bundling of the strands.

This crimp profile is particularly suited for tubular cable lugs, solderless terminals to DIN 46234 with and without insulation and cable lugs for fine-stranded conductors.

Although the indent crimp is a non-standardised crimp profile, it is nonetheless used for standardised cable lugs. Hence: make absolutely sure that the materials and crimping tools are compatible. Otherwise there is a risk of individual strands becoming crushed, which can impair the mechanical and electrical properties.

Klauke's product portfolio:

> crimping tools

> crimping dies 

The quad-point indent crimp: for copper

The quad-point crimp found its way into German control cabinet construction from the USA. In this sector, it is used up to 1 kV. However, it has also proved useful for other connections too, in locomotive drive units for example. This crimp profile is suitable for tubular cable lugs and connectors with cross-sections from 10 mm² to 300 mm² in combination with conductor types to DIN EN 60228, Classes 2, 5 and 6.

The advantage of the quad-indent crimp over a standard indent crimp is the centric force and the simple processing, which does not require different dies. You can process all sizes in the cross-sectional range above using just one crimping tool – this is extremely practical. The quality of the crimp therefore depends on the effort required and the tool used. However, the quad-point indent crimp is not suitable for insulated connectors, since the indents can damage the insulation.

Klauke's quad-point indent crimper:


Crimping (10 - 240 mm²) with open head:


Crimping (16 - 300 mm²) with closed head: