Cool Tools: Fish Tape

Fish tapes are essential basic tools that are easy to take for granted, but imagine pulling cable through on a large commercial job without them.

The purpose of fish tape hasn’t changed since someone discovered that getting wire through a conduit would be simplified by “fishing” a rigid wire through the conduit and pulling it back out. However, fish tapes have come a long way since the first steel pulling wire was enclosed in a case.

Today’s tapes are made from a variety of materials; they pay out and reel in easier and faster, and they are more durable. In addition, a variety of accessories make pulls faster and more efficient.

For placing voice/data/video cabling, fish rods and poles are often used, rather than conventional fish tapes, and fiber optic cable requires careful handling.

Fish tapes come in a variety of materials, including steel, stainless steel, stranded steel and fiberglass. Professional tape lengths typically range from 25–400 feet.

“Steel is a good general-purpose, fish tape material,” said Jason Schaper, tools and supplies product manager at Ideal Industries, Sycamore, Ill. “Steel tape is durable, low-cost, and known for its push and pull strength. There have also been improvements in steel quality, such as moving to blue steel, which is rust-resistant, more durable and less likely to kink.

[SB]“Stainless steel has all of the qualities of steel with the added benefit of rust resistance and is good for use in underground conduit that often contains water and condensation. Additionally, it is favored in coastal areas where there is airborne salt that accelerates oxidation. Laser-etched footage markers have expanded the use of fish tape not only as an installation tool but also to measure conduit to allow electricians to accurately know the length of wire needed and thus reduces waste. Nylon generally is not used by professional electricians because it has lower push strength and tends to curl,” he said.

Tape length and tensile strength are important aspects to selecting the right type of fish tape. The larger the conduit dimension, the thicker and stiffer the tape needs to be to avoid jams.

Ease of payout and retrieval of the tape is largely dictated by the case design. Cases should allow for smooth, quick retrieval, while preventing the tape from kinking. Retainers keep the tape properly positioned at the opening and prevent breakage. Ergonomically designed handles are stronger, slip-resistant and large enough to grasp from the top or the side, even when wearing gloves.

“Wire-pulling lubricant is an essential tool for all wire and cable installers and helps prevent cable failures caused by excessive pulling stresses,” Schaper said. “The best lubricant will help keep cable from twisting, scraping and stretching as it is pulled through the conduit. Lubricants make the work easier and faster, saving on labor costs.”

Fish poles simplify the installation of electrical and data cables in walls, roof voids, raised floors and suspended ceilings. The poles also assist wire pulls in areas where insulation is already installed. Most are nonconductive and can be used with different cable and wire types.

“One of the biggest areas of improvement we hear about is the need to make reading the numbers on the tape easier,” said Sumeet Pujari, senior product manager at Greenlee, Rockford, Ill.

To address this, look for fish tapes with laser-etched numbers. These distance markings are etched into the steel every inch for maximum readability, and ­diamond-shaped marks remain legible over the life of the fish tape, compared to the standard hash mark.

“Also look for fish tapes that have measurement in both feet and meters,” Pujari said. “This will help improve productivity by saving time because it eliminates a separate measuring step during the installation process.”

How easily fish tapes can be wound is very important.

“A fish tape that is housed in a self-tensioning case for easy winding is the best,” Pujari said. “Some of the wide, impact-resistant rewinder cases come with viewports to ensure the tape fits back in the case. A retaining strap is on the inside to hold tape secure. Fish tapes with a sturdy thumb control assure that winding and rewinding can be done quickly and easily.

“The biggest influencing factor for metal tapes is rust. Conventional steel rusts, causing added friction and shortened lifespan of the tape. Look for corrosion-resistant wire that has the same strength as conventional steel tape but comes with smooth plating,” he said.

David Mueller, senior product manager at Klein Tools, Lincolnshire, Ill., said improvements include tape-­material strength, rounded edges to reduce surface contact and friction, attachment methods of tips and leaders for nylon fiberglass fish tape, and efficient flow of the tape. Modern cases incorporate ergonomic designs that account for how they fit and feel in the user’s hand. 

“Flat steel usually is 1⁄8-inch-wide spring steel specially made to resist corrosion and breakage,” he said. “Spiral steel is a tight spring coil material. Nylon/fiberglass tapes have a fiberglass core rod coated with a nylon resin exterior. Tape lengths typically used by electricians range from 25–50 or 65 feet and generally are used for short-run residential work. Tapes of 100- and 200-foot lengths are used on longer runs on commercial projects.”

He added that standard steel tapes are by far the lowest cost option. Spiral steel and stainless steel are more expensive. Nylon/fiberglass are the most expensive.

“The longer the run, the more stiffness and ability to push the tape is needed,” Mueller said. “A softer resin tape without fiberglass reinforcement will bunch up and jam after 100 feet or more. In situations where electricians cannot ‘power down’ a work area, a safe choice is a nonconductive fiberglass tape with a plastic leader tip.

“Steel fish tapes can arc at the breaker panel, causing fire or injury to electricians at either end of the tape. Many large corporations and contractors may mandate use of nonconductive fiberglass tapes due to electrocution precautions,” he said.

In commercial installations, up to 15 wires might be pulled at once into a new empty conduit run.

“The weight of all this wire usually will require a steel tape due to steel’s high-tensile-strength,” Mueller said. “Other lower-tensile-strength material options may break during installation. Installing into new conduit is usually easiest, since there is no friction or tangle of existing wires to pass by. Many material options will work well. When the conduit has several existing wires, some materials, such as steel, can cut into the resin jackets of the wires when passing over the bumpy/ropy topography of the existing wire bundle due to the extreme friction built up over the run. In these situations, a slicker, low-friction, nylon exterior of a fiberglass tape may be best.

“Many electricians install wire in plastic conduit running in concrete slab floors or outside to transformers where it’s common to have some water present in the conduit. The best material choice for this situation is a nylon/fiberglass or stainless steel tape. Both resist corrosion. When a wet steel tape is coiled up, it will rust. Also, in humid/salt water regions such as the Gulf Coast, electricians tend to prefer noncorrosive materials for similar reasons,” he said.

Tips or leaders are important accessories. There are steel or plastic eyelets and 6- to 7-inch spiral steel leaders with steel eyelet tips. The basic eyelets are least expensive and offer top strength from steel or moderate strength combined with nonconductivity for the resin eyelet. The popular spiral steel leaders have an extremely flexible leader end for navigating through bends and into junction boxes.

Southwire Tools, Carrollton, Ga., is relatively new to the fish tape market, offering steel tapes from 25–250 feet and fiberglass tapes in lengths of 50 and 100 feet.

“Steel tapes are selected for durability and tensile strength,” said John Payne, product director at Southwire Tools. “Fiberglass fish tapes are used for their nonconductive value. Southwire has only been in the fish tape market for three years, so our entire product line could be considered a significant change. Pulling grips, circuit-size pulling heads and ­tensile-strength poly lines also are available.

“We conduct continuous research into durability and end-user experience, and we look forward to introducing innovative new fish tapes in the near future,” he said.

Glow-in-the-dark fish sticks are available in lengths of 8, 12 and 15 feet, and multiple accessories are available in kits.

“Southwire’s recent acquisition of Seatek adds the fish tape puller to our product offering,” Payne said. “This simple tool pulls fish tapes without having to use sidecuts or hands.”

The 11-inch tool is made of hardened steel and clamps to a fish tape with a cam-action hinge, holding the tape securely regardless of pulling force. Two-handed pulling action eliminates the need to use pliers for pulling and provides twice the pulling force.

About the Author

Jeff Griffin

Construction Journalist

Jeff Griffin, a construction and tools writer from Oklahoma City, can be reached at

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