Crimp connectors

Crimp connectors

The crimp connections have proven themselves millions of times over in all areas of industry, automotive technology, aviation, the transport industry, and in medical equipment.

Crimp connectors are also known as crimp contacts. They come in a wide range of versions and designs and are divided into two main groups. The solid/turned crimp connectors or contacts are referred to as being “closed”, while the punched/rolled crimp connectors or contacts are “open”. In an electrical installation, these crimp connections fall under the heading of “solder-free electrical connections”.

Test specifications and main groups

The scope of performance as well as test specifications are described in the European standard DIN EN 60352-2. “Crimping” is a joining process to permanently connect one or more conductors with a contact. A stripped conductor is inserted into the crimp zone of the contact and connected by means of a defined crimping process. This results in a permanent, reliable crimp connection that cannot be detached.

The following main groups define the various connector types, with a broad spectrum of dimensions and conductor cross-section ranges: punched-rolled contacts, turned contacts, hard-soldered crimping cable lugs, tubular and compression cable lugs, butt connectors, insulated crimping cable lugs, pin cable lugs, uninsulated and insulated ring cable lugs, uninsulated and insulated fork-type cable lugs, uninsulated and insulated slip-on sleeves, and coaxial CATV connectors.

Crimp profiles

The B crimp profile is mainly used for punched-rolled contacts. Solid turned crimp connectors/contacts mainly exhibit profiles with four-mandrel crimping (4/8 indent), square, oval, mandrel crimping, twin mandrel crimping, WM crimping, hexagonal (hex) plus mandrel crimping, and B crimp.

Mechanical crimping pliers with a ratchet system or hydraulically operated tools with different die sizes and crimp profiles process cross-sections larger than 10 mm². Depending on the machine type, square and four-mandrel profiles up to 10 mm² are installed in electrical, pneumatic, and electro-pneumatic crimping machines. For larger cross-sections, such as for a charging connector, the B crimp profile is also used.

Other profiles, such as WM crimp, O crimp, indent crimp, and double indent crimp, are used for processing ferrules, tubular and crimping cable lugs, and crimp connectors up to 300 mm². DIN 46230, DIN 46234, and DIN 46235 are used as a reference for the standard.

Crimp profile selection

This time-saving, cost-effective connection method has proved itself millions of times over for many decades. Selecting the right design, however, is a very complex task. For standard-compliant crimp connections, the perfect interplay between the cross-section of the litz wire, crimp contact, crimping tool, and correct tool setting is crucial. Selecting the crimp profile depends on various parameters, such as the crimp connector or crimp contact, the applicable standard, the area of use, and the specific connector type.