Crimpers top the list of essential tools for making electrical and data communications wire and cable connections.

 By the application of force, a crimping tool makes a permanent connection by either compressing (crimping) a connector around a prestripped wire or cable, or by pushing wire or cable into a connector designed to pierce or displace the insulation and attach it to the conductor.

“Connections must be made without compromising the integrity of the electrical circuit or system as it has been designed,” said Jerry A. Woodward, product manager at Thomas & Betts Corp. “Each connection should meet all industry guidelines and standards. A connection should never be the weak link in a wiring system.”

Advances in crimping-tool designs make today’s models more efficient and easier to use than earlier versions.

Crimpers fall into two general categories classified by:

- Whether they use die sets for different connector types and sizes or are “dieless” models;

- The type of power source that applies crimping pressure—manual, hand-hydraulic, remote-hydraulic, or battery-powered.

“Dieless tools are nice because they are much simpler to use,” said Jim Eisele, Greenlee Textron product manager. “Dieless tools can crimp a range of connectors without making any change, or sometimes by just an adjustment to the tool, but their range is relatively limited. Die-type tools can be used to crimp a much broader range of connectors, but they require a different set of dies for each connector type and size to be crimped.”

Whether manual or power-assisted crimpers are employed depends primarily on the cable size being connected and the volume of work to be completed.

“Manual tools range from the small, single-hand-operated, plier-type tools, to larger versions that require two-armed operation,” said Robert J. Horky, Panduit Corp. business development manager. “Larger crimpers can be manually operated or are manually-pumped, hydraulic-assisted tools. Power models come in battery-powered and electric (110V) hydraulic pump-powered versions. Battery voltages range from 12V to 18V and operate tools in sizes from relatively small hand tools about the size of a drill to battery-powered hydraulic pumps.”

Manual tools usually are used for connecting wire and cable in small-to-medium sizes where a small number of crimps are to be made. As cable size and the number of crimps increases, power tools usually are preferred.

“New battery-powered crimpers have more power than older models, are more portable, make crimps faster with less fatigue and allow more crimps per battery charge,” said Angela Toppazzini, advertising coordinator, FCI-Burndy Products. “In addition, today’s tools are more ergonomically friendly, faster and easier to use. The choice of which crimper to use depends not only on how much crimping is to be done and the size of the wire, but where work will be done, tool portability and tool cost. For data-communications work, generally, the tools preferred have heads that are rubber-covered to avoid electrical interference.”

Nancy Szankowski, product manager at Klein Tools Inc., said that data-communications workers usually prefer full-cycle ratcheting crimpers to meet tighter tolerances set by industry standards.

“Data-communications crimping tools usually are manufacturer specific,” she added. “Lightweight, multifunctional, and curved grips and handles make today’s crimpers easier to use. Power crimping tools are used for utility work. Many professionals in the electrical and MRO markets prefer to lighten the carrying load on their tool belt or pouch by using multifunctional tools.”

Eisele of Greenlee Textron said data communications tools are usually manual because the wire sizes to be crimped are small: “They differ from electrical crimping tools in that the shape of the crimp cavity is different because data communications connectors are different than electrical connectors.”

Because smaller-size data-communications connections can be made with manual crimpers, tool cost is significantly lower, said Woodward of Thomas & Betts. “But data communications also has requirements for larger connectors—especially for outside plant—and those connections would require the same tools used for electrical work.”

Panduit’s Horky said the most common crimper for small gauge electrical wires—22 AWG through 1 AWG—is the handheld, plier-type tool.

“These tools,” he said, “can crimp noninsulated or insulated connectors with barrels either formed (butted seam or brazed seam) or made from seamless copper tubing. Some have pockets for both insulated- and noninsulated-type connectors, thus reducing the number of tools a worker must carry. For those requiring the assurance of a full and complete crimp, hand tools with a controlled-cycle mechanism would be the next most popular.”

As the size of wire or cable increases, the tool required must be larger to permit the compressive force necessary to make the crimp to be applied.

“In the 8 AWG through 250 kcmil range,” Horky continued, “the most popular-type tool would be a large manual crimping tool capable of providing 6 tons of compressive force. Above 250 kcmil, the crimper is typically a hydraulic tool either manually or electrically pumped. Compressive forces on these type tools can go as high as 15 tons or more, with most being in the 12- to 15-ton range.”

If you need only a few crimps on cable 4 AWG and smaller, use manual tools, said Eisele.

“Several styles and types are available, depending on what you’re crimping and if you prefer interchangeable dies, rotating noninterchangeable dies and indentor tools,” he said. “You can adjust the latter to the proper connection choice.

“For larger cable sizes, you need hydraulic tools for the force needed to get a 6-ton, 12-ton or even 15-ton crimp,” Eisele added. “A remote hydraulic pump can power these hydraulic tools. There are also hand-powered units and those using a battery-powered motor. All are available in a variety of interchangeable die and dieless types.”

Ergonomics, ease of operation, and multifunction capabilities are driving forces affecting crimper tool designs.

To use a manual tool to make connections of large cable requires great physical strength, which is tiring and can limit productivity. Project owners and contractors also are concerned about the risk of physical injury.

“A study by EPRI (Electrical Power Research Institute) concluded that the significant increase in muscular loading while using manual tools can lead to injury,” said Woodward. “Tools today, including crimpers, are designed for ease of use and for the safety of the tool user—and ergonomic considerations are intended to reduce the propensity for injury and long-term ailments.”

Power crimpers virtually eliminate the need for physical exertion by the operator, and manufacturers contributing information to this report agree that the industry is moving toward battery-powered models.

“We see a trend to replace all manual and manual-hydraulic crimpers with self-contained, battery-powered tools,” said Woodward, adding that the trend is accelerating as tests and reports document the value and economy of battery-powered crimpers.

“Battery-powered tools are growing in popularity for cable installation and termination operations,” said Eisele. “The main benefit of battery-powered tools is their fast cycle times—5 seconds to 20 seconds for most operations. Users also like the tool’s consistency. Particularly in crimping operations, many appreciate the fact that the tool controls the cycle, not the operator. These tools are also relatively compact, easy to get into tight panel boxes and they reduce fatigue from repetitive operations.”

Horky said that battery technology continues to improve, allowing more crimps per charge and larger connectors to be crimped. The newer batteries also recharge faster. “And as hydraulic pumps become more efficient,” he said, “cycle times decrease, overall weight is reduced and balance is improved. All of these factors make battery-powered tools more and more the tools of choice.”

Making dies easier and faster to change makes crimpers both easier to use and more productive.

Research showed manufacturers that die-changing functions had to be simple, fast and done without tools, said Eisele, and new tool designs reflect this.

“In addition, index numbers in the dies permanently emboss themselves into the crimped connection to provide visual traceability that the correct die was used to install the crimp,” said Horky.

Until recently, crimpers have been single-purpose tools, but that has changed. “Multifunction tools are now being introduced to the market as tools that can perform both cut and crimp functions,” said Eisele. “In some cases, they come with additional functions such as a knockout punch adapter. One recently developed tool enables installers to punch holes, cut a wide variety of materials and crimp electrical connectors using several different die types—all with just one head. Tools that combine multifunction capability with battery power are state-of-the-art today.”

In addition to performance, the more multifunction tools an electrician has, the fewer tools he or she needs to bring to job sites.

“Multifunction crimpers combine high operator productivity with high tool productivity,” said Eisele. “As contractors become aware of this, we will see more and more of a demand for them on all types of projects.”

What about crimpers of the future?

“Because connectors are not changing,” Eisele said, “we don’t anticipate much change in the way crimps are made. But various manufacturers will continue to develop battery-powered tools that are smaller, lighter, operate faster, are able to perform more functions and will be less expensive.” EC

GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at 405.748.5256 or