Crimping Tool Selection Guide
Crimpers are tools used to make cold weld joints between two wires or a wire and aconnector, such as lugs. Ideally, the electrical and mechanical properties of the weld joint are as strong as the parent materials.
Crimping tools are sized according to the wire gauges (using AWG - American Wire Gauge) they can accept. Some come with interchangeable die heads that allow for a wider range of wire sizes and connectors.
Hot welding joins two surfaces using intense heat, while cold welding applies intense pressure to the surfaces being welded. As such, cold welding is also often referred to as an example of solid-state welding, because the parent materials do not change states from solid to liquid and back.
How to Use a Crimping Tool
First you will need to strip the length of wire that you want to crimp. Then, attach the connector. For crimping tools with interchangeable dies, you will need to select the right die head for the connector by matching wire gauge ratings. For dieless crimpers, you will need to match to the proper groove. Finally, apply pressure, take out the newly crimped connector, and give a few tugs to make sure you have a solid and secure connection.
How to Select a Wire Crimper
The content we provide is meant to inform you and help support the proper selection and use of crimpers. As always, we recommend you consult a licensed and competent electrician to help you with the sizing and selection of parts for your particular application. Need more help? Call our technical support engineers for live, front-end support.
How often will you be making crimps?
Hand or hammer crimpers are relatively cheap and may be your best options if you only crimp occasionally.
Hydraulic and automated crimpers (e.g. battery powered) are more expensive but will prevent strain and injury due to repetitive crimping operations.
Indent vs. Compression Style Crimps
Indent style crimps are usually used for crimping fine stranded and compacted conductors. Indent crimping can be done with easy-to-operate hand crimping tools. This style of crimp yields great pullout resistance and good electrical performance when correctly made with a properly sized tool for the cable and connector. As the strands are formed tightly together inside the connector, nearly all air gaps are removed from the conductor. However, it is more difficult to check if an indent style crimp has been properly made compared to hex-style crimps.
Indent crimps are for processing lugs according to DIN 46234 and connectors per DIN 46341 part 1, form A+B, which are suitable for conductors classified under VDE 0295 2, 5 and 6. Lugs and connectors that comply with these standards have large outside diameters that can accept all cable types.
Indent crimp made with a hammer crimper.
Hexagonal style compression crimps, the most common type of crimp, create strong mechanical connections. The advantage of this style crimp is that force is applied consistently from all directions over a larger area during crimping, preventing any damage to the conductors. This style crimp is an industry standard for aluminum and copper cables up to 1000 kcmil. Hex-style crimps yield superior electrical performance in addition to great pullout strength.
It is important that the size of the crimping dies are matched exactly with the materials and dimensions. The range of applications for hex-style crimps are crimping of conductors as per VDE-0295 categories 2, 5 and 6 and the processing of non-tension connections of aluminium cables per DIN48201 part 1 (DIN EN 50182 for aluminum ropes).
Hexagonal compression crimp made with a hydraulic crimper.
Wire Size & Crimp Quality
The thicker the wire (e.g. 1/0, 2/0, etc.), the more power you will need to get a proper crimp. At a certain point, manually powered crimpers will take too much effort or cannot provide enough pressure to crimp thicker wire gauges.
How can you tell if you've made a high quality crimp with a hexagonal compression type hydraulic crimper? See the quick reference guide below.
Corners should be as crisp and sharp as possible.
Corner radius should be shorter than the length of the flat sides.
Die size is too large. Select a smaller die.
Die size is too small. Select a larger die.
Dies vs. Dieless
Dieless crimpers are faster to use because you do not need to switch out the die head every time you want to crimp a different size wire. However, die crimpers allow for a wider range of wire sizes to be crimped and are often less complicated in design.
Common Crimper Types
These handheld crimpers used for smaller wires. Some can also be used to cut and strip wire as well.
Hydraulic crimpers can apply much more pressure than small handheld crimpers and are used for thicker wires.
Proper maintenance requires periodically changing the oil and oil filter so that the hydraulics remain fluid and do not clog. You will also want to make sure there is no dust or air inside the tool after replacing the oil.
Hammer crimpers are cheap, compact, and can crimp a wide range of wire sizes simply by adjusting the height of the movable wedge. The larger the lug, the more strikes you will need to make with the hammer.