From electrical design to maintenance, engineers must determine what electrical clips (also called alligator or crocodile clips) are best suited for their project.
These clips can range from small to large, be made of a wide range of materials, come in various jaw types, handle wide ranges of electrical current and can be certified for safety by being UL-listed.
With such a wide range of options, there are many factors to come into play when selecting clips
Typically, electrical and electronic clips are rated by their ability to handle varying levels of current which is measured in amps so you will need to know the amount of current that you will be dealing with.
Once you know the level of current, you can calculate the amperage rating required for the clip.
The formula for Amps is Watts divided by Volts.
The amperage capacity of a clip is typically listed right on the clip itself.
Generally speaking, larger clips are able to handle more current, however, that doesn’t always mean a larger clip is always necessary. Solid copper clips are able to handle higher levels of current and carry a higher amperage rating than its zinc plated steel counterpart. For example, a heavy duty clip for battery and test work applications may be rated at 50 AMPS for the zinc-plated steel version while the same sized clip made in solid copper is rated at 100 AMPS.
Clip Jaw Types
Another factor to be considered is how the clip needs to connect to its point of contact. Clips come in all shapes and sizes with different types of jaws and teeth. Clip jaws can come flat nosed, with teeth, or wrap around a terminal or pipe. Some clips have flat wide noses with teeth and others may be rounded to grab round objects. Deciding which clip to use is dependent of what the clip is grabbing on to and will vary per application.
Flat nosed clips are typically used in paint grounding.
Smaller clips with teeth are used for test and measurement.
Larger clips that wrap around will provide a strong grip and may penetrate a layer of paint. These are often used for battery charging and grounding.
Flat wide jaws with teeth are perfect for grounding and work holding uses.
There are, however, a tremendous number of applications for all types of jaw styles. As technology progresses, so do clips, with new types being invented all the time.
For more on different types of clips and what they are used for, check out our guide to clips.
Clip grabbing strength, or clamp pressure, is another factor to take into consideration when selecting the right clip. Clamp pressure usually increases as clip and spring size increase. Larger clips will have a stronger grip than smaller clips. In some cases clips can be made to have less clamp pressure which can be helpful for delicate or detailed situations.
There are many different sizes of clips and size can sometimes be important to consider. One determining factor is if there is a space requirement. Another factor is the amount of clamp pressure required, as well as the amperage rating needed.
Some clip sizes are determined by the application itself as there may be limited space where the clip can fit. Naturally if you have a small space then you probably will pick a smaller clip.
Higher amp rated clips tend to lend themselves to uses where a tight space is not a concern. The environment may dictate what a clip size may need to be as the larger clips tend to hold up better in harsh environments such as electroplating.
There is no real guideline on determining what clip size to use. Some engineers try to make sure they have the right amperage rating, clamp pressure and jaw type in the smallest package possible to reduce the possibility of “overkill” and inflating costs unnecessarily. Other engineers go one step up in size to ensure all bases are covered. In most cases, several different sizes of clips are used in various prototypes to test first hand which clip size is best.
Clips are made with zinc or nickel plated steel, stainless steel, solid copper, gold plating and even nickel-silver.
Generally speaking, zinc or nickel plated steel is the most cost effective material used in clips.
Solid copper clips can handle higher levels of current better than similarly sized clips made of other materials.
The environment where the clip will be used can determine what material should be used for a clip. For example, stainless steel clips can withstand marine, caustic or corrosive environment better than other materials. Other clips that can be used in marine environments are marine rated clips which are made of solid copper for greater connectivity but with moisture resistant springs which significantly extend the life of a clip used in the vicinity of water and salt.
We did an experiment to show how marine and stainless steel clips hold up compared to other clips. Read about it here.
Read about different metal finishes for clips here.
Safety is always a consideration when working with electrical components, but some more than others.
For instance, when using clips and cables for grounding and bonding, an exposed clip works just fine, while other applications it may call for an insulated clip.
UL Listed products are certified for safety. UL Listed clips and connectors are certified to insure that human hands cannot come in contact with the conductors while in use and energized.
Other applications may call for clips to be utilized in a “hands free” environment which means that the clips are not manipulated or touched while a circuit is energized. The clips still need protection from touching each other or other parts which could interfere with the electrical signal or cause a short, so insulators or “boots” are placed over the clips to protect them.
For help in selecting clips with different features, try our clip selector.