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High Power Pin and Sleeve Devices


Click here to see our entire line of Ferrules. 

A ferrule is an internal component that is used for better electrical contact in applications where the spread of bare strands could cause a problem. Ferrules are types of objects that are used for fastening, joining, sealing or reinforcement. Interpower ferrules come in uninsulated wire ferrules, insulated wire ferrules, or double wire ferrules.

For part numbers see the Ferrule Selection Guide.

Ferrules come in two styles—insulated and uninsulated. The insulator is added to the “top” of the ferrules. The insulator helps to eliminate arcing in the assembly.

Uninsulated Ferrule Insulated Ferrule Double-Wire Insulated Ferrule

The ferrules are sized by metric measurement, so international wire sizes will fit properly in the ferrules. North American conductors are not sized metrically. The metric size of North American conductors is approximate. For example, 18 AWG conductor is approximately 0.82mm2. The size is between the metric 0.75 and 1.00mm2. A ferrule meant for 0.75 will be too small, so the next size larger will be needed. The 1.00 size ferrule will allow the 0.82 conductor to fit and permit 80% of the conductor to fill the ferrule space. Metric sizes do not include 2.00mm2. It moves from 1.50 to 2.50mm2. This affects 14 AWG conductors whose measurement is 2.09mm2. The only solution is to use 2.00mm2 ferrule and make do with the crimping.

In selecting the kind of ferrule to use, there are several factors that should be considered.

Although ferrules are commonly used in Europe, they are not well known in North America. Part of the reason is that much of the equipment production in Europe is focused on machinery. Interconnections in machinery are usually based on terminal blocks and other connections that make screw connections desirable. In North America (where electronic equipment production focuses on computers, telecommunications, and medical equipment) interconnections are typically very small and terminal blocks are inappropriate in many cases. These devices are usually approved in Europe as part of the equipment. They do not have separate approvals. In North America, they are also subject to evaluation at the time the equipment is evaluated by UL and CSA for certification.