Steel Fish Tape vs Fiberglass Fish Tape: Which One is Better?

Overview: Why the Material Matters

Choosing between steel fish tape and fiberglass fish tape isn't just about cost — it's about matching the tool's material properties to your working environment, the types of cables you're installing, and your safety requirements.

Both materials have distinct advantages and limitations. The right choice for a residential electrician doing short runs in new construction may be entirely different from that of a telecom contractor working in underground municipal ducts.

Steel Fish Tape: Features & Performance

Material Properties

Steel fish tapes are made from high-carbon spring steel, typically in flat or round profiles. They offer exceptional stiffness and push-through force, making them effective for relatively straight conduit runs.

Advantages

• High push force: Steel's stiffness transmits pushing force efficiently through the conduit

• Excellent for straight runs: Minimal bends or junctions work well with steel

• Lower cost: Steel tapes are generally 30-50% cheaper than fiberglass equivalents

• Wide availability: Available at every electrical supply store

Disadvantages

• Conductive: Dangerous near live wires — can transmit electrical shock

• Prone to kinking: Once kinked, the tape is permanently weakened

• Corrodes in wet conditions: Not suitable for underground or damp environments

• Heavy: Longer steel tapes become very heavy and fatiguing to use

• Memory issues: Can retain curved shape after use, making storage difficult

Fiberglass Fish Tape: Features & Performance

Material Properties

Fiberglass fish tape (also called FRP fish tape or fiberglass snake) is made from fiberglass filaments embedded in a polymer resin matrix. It is produced in round profile for maximum flexibility and strength.

Advantages

• Non-conductive: Safe to use near energized electrical systems

• Corrosion resistant: Performs perfectly in wet, underground, and outdoor environments

• Lightweight: Weighs up to 70% less than equivalent steel tapes

• No kinking: Bends without permanent deformation

• Excellent flexibility: Navigates multiple bends and curves more easily

Disadvantages

• Lower push force: More flexible than steel, so less effective at pushing through tightly packed debris

• Higher cost: Quality fiberglass tapes cost more upfront

• Can splinter: Worn or damaged fiberglass can produce irritating slivers

Side-by-Side Comparison

When to Choose Each Type

Safety Considerations

For electricians who regularly work in panel boards, near overhead lines, or in environments with uncertain energization status, the safety advantage of fiberglass is worth the higher cost. One electrical incident can cause serious injury, death, or costly legal liability.

Frequently Asked Questions

Q: Can I use a steel fish tape to pull fiber optic cable?

A: While possible in clean, straight conduit, steel fish tapes are not recommended for fiber optic installation. The risk of jacket damage from kinks or corrosion, combined with the cable's sensitivity to crush force, makes fiberglass the preferred choice.

Q: How do I store my fish tape to extend its life?

A: Always rewind steel tapes fully after use to prevent kinking. Store in a dry location. Fiberglass tapes should be kept on their reel and stored away from extreme heat and chemicals.

Q: Can fiberglass fish tape be used with power pulling equipment?

A: Yes. Fiberglass duct rodders in particular are designed for use with pulling equipment. Standard fiberglass fish tapes are primarily manual-use tools — for powered pulls, use an FRP duct rodder with appropriate ratings.