Strip Cable Jacket with a Cable Knife

Job: Remove a specified length of outer jacket from an identified de-energized cable using shallow controlled 90600 scoring/slitting passes and peeling, without nicking conductor insulation, shield, braid, armor, fillers, drain wire, optical elements, or other required underlying layers

Time: Five to thirty minutes per end after identification and setup; longer for unfamiliar, large, aged, bonded, armored, shielded, filled, or multilayer cable

Difficulty: Advanced — damage may be invisible until insulation test, commissioning, heat, moisture, motion, or service voltage exposes it

Everything else: Exact cable manufacturer stripping/termination instruction; current drawing/specification; authorized disconnect/lockout/tagout and voltage-testing equipment; cable support/fixture; gauge-matched stripper, jacket ripper, scoring tool, sheath/armor tool, or powered preparation system when specified; depth witness/matching scrap; compatible marker/tape; layer-safe pliers; inspection light/magnification; required electrical test equipment; task-selected arc/electrical/cut/eye protection; guard and sharps/waste control

The knife is not electrical protection

The 90600 has a hardwood handle. No insulation rating, live-work listing, voltage class, dielectric property, or protective certification is accepted.

Wood is not permission to work energized.

Before hand stripping:

disconnect through the authorized procedure;

verify absence of voltage with approved test equipment and method;

control stored/induced/backfeed energy;

protect adjacent energized parts;

confirm the cable’s identity at both ends.

This application does not authorize an exception or live work.

Read the exact 90600 evidence

model key 90600;

Cable Knife / Cable Knife 405 identity;

catalog width 7/8 inch;

catalog thickness .072 inch.

catalog blade length 3-1/4 inches conflicts with the listing title’s 1-3/8 inches; do not resolve either as the unqualified blade length;

the family’s “13-gauge” wording conflicts with .072 inch on Hyde’s own gauge ladder; print no resolved gauge;

steel type is unstated;

blade profile is unstated;

“405” is not decoded;

exact distinction from sibling 20600 is not established.

Also open: bevel, hardness, flex, insulation, jacket/material capacity, depth, sharpening, and guard.

Decide whether a knife belongs in the method

Use the cable/connector/equipment manufacturer’s instruction first.

Prefer its specified:

controlled-depth jacket scorer;

armor/sheath tool;

braid/shield preparation tool;

rotary/powered system;

A freehand cable knife survives where size, irregular construction, legacy material, limited access, or a special termination makes matched tooling impractical—but only under a qualified method.

Do not use this guide to strip:

fiber-optic elements without their preparation system;

armored/mineral-insulated/high-voltage/specialty cable without exact instructions;

cable whose warranty/certification requires dedicated tooling;

a layer you cannot positively identify.

Identify the complete cable construction

From markings, drawings, datasheets, and end view, record:

cable type/manufacturer/part;

conductor count/size/material;

outer jacket material and thickness if specified;

shield/foil/braid;

drain/ground wires;

individual conductor insulation;

optical/pneumatic/sensing elements;

moisture block/fill;

required strip length;

connector/gland/termination sequence.

Do not infer layer depth from diameter or color alone.

If markings are missing or construction differs from the drawing, stop for identification.

Define what must remain untouched

The work instruction must name:

layer being removed;

layer directly beneath;

permissible witness if any;

prohibited nicks/scores;

minimum retained shield/braid;

required jacket edge;

disposition for damage.

“Don’t cut too deep” is not an executable criterion.

For many terminations, a conductor-insulation nick, severed braid strand, cut drain wire, or scored shield is a reject even if the cable still functions now.

Inspect and support the cable

Inspect the preparation length for:

cuts/crush/flattening;

heat/chemical damage;

water/fill leakage;

insufficient service length;

stored twist/bend.

Support the cable so it cannot roll or whip.

Respect its manufacturer minimum bend radius and handling requirements; the 90600 record supplies none.

Do not clamp hard enough to deform internal layers.

Inspect the 90600

With all energy controlled, inspect:

edge and tip/profile as physically present;

hardwood handle cracks/looseness/contamination;

Do not test the edge on skin.

Do not continue with a dull knife that requires force. Force is what drives through a released jacket into insulation.

Use only a qualified physical-geometry service method.

Qualify on matching scrap

For unfamiliar construction, use a matching cable offcut.

temperature/age/condition;

ring and slit directions;

Make shallow witness passes, then dissect the sample.

Confirm the underlying layer carries no score, glint, compression, lifted shield, cut strand, or displaced component.

A jacket that looks clean from outside can hide a continuous insulation ring score.

Record the proven method but do not convert it into a universal 90600 depth/cable capacity.

Mark the strip boundary

Mark the circumference with a compatible method that does not damage or contaminate the jacket.

longitudinal slit path;

shield/drain preservation zone;

final inspection reference.

Do not use the knife to scratch a layout mark through the jacket.

Build a safe knife path

Arrange the supported cable so:

the ring path is visible;

the slit runs away from hands/body;

the blade cannot exit into the supporting palm;

no person is downstream;

the cable cannot roll;

adequate light exposes layer color/texture;

waste can peel without jerking the knife.

Use a cable vise/fixture when possible.

Never hold a cable end in the fist and carve toward the thumb.

Select hand protection for sharp jacket/armor/knife hazards while retaining control under OSHA’s hand-protection standard, and eye protection for snapping jacket, wire, or debris under 1910.133.

Establish the ring score shallowly

The ring score defines the jacket termination edge; it must not become a ring cut in conductor insulation.

Present the physical blade at the qualified shallow angle/depth and rotate the cable or tool through the proven method.

Use multiple light controlled passes when required by the qualified sample.

Inspect after each circuit. Look for a change in:

underlying layer witness.

Stop as soon as the jacket boundary is adequate for controlled peeling.

No pass count/depth is a Hyde fact.

Avoid the circumferential-nick trap

A complete ring nick in underlying insulation concentrates bending/electrical stress around the conductor.

Never “make sure” by pressing until the jacket separates fully.

If the jacket is bonded, hard, cold, thick, filled, or layered, return to the cable-specific tool/method.

If any underlying layer becomes visible unexpectedly:

guard the knife;

hold the cable for authorized disposition.

Do not rub or smooth the mark away.

Make the longitudinal slit

Orient the slit where the termination instruction allows and where protected underlying construction is best controlled.

Begin at the end or ring according to the qualified method.

Use shallow slicing/scoring passes away from the holding hand.

Keep the blade aligned with the cable axis; a spiral path increases hidden contact length.

twist the point under the jacket;

saw over braid;

slit across a drain wire;

lever the blade as a screwdriver;

cut toward the body.

Stop if the cable rolls or internal texture appears.

Peel instead of recutting deeper

Flex the jacket at the score and use the specified pliers/peeling method to separate it from underlying layers.

Peeling reveals whether the score is adequate while keeping the blade out of the interior.

If a small bridge remains, re-support, identify the bridge, protect the underlayer, and sever only through the qualified method.

Do not run the knife blindly under the jacket.

Control the removed jacket; cut edges and embedded fillers can be sharp.

Handle bonded, filled, shielded, and armored constructions

These require exact manufacturer methods.

Bonded jacket: uncontrolled peeling can lift shield/insulation.

Gel/fill: contamination can hide nicks and affect grip/cleaning.

Foil shield: a light knife contact can sever it.

Braid: cut strands change coverage/termination.

Armor/sheath: use the specified armor tool; the 90600 is not proven armor-cutting equipment.

Optical/sensing elements: tiny damage can be catastrophic.

Stop at the first contradiction between actual and documented construction.

Inspect every layer after removal

Clean only through the cable system’s specified chemistry/method.

Under bright light/magnification inspect:

jacket cut edge;

shield/foil/braid;

signs of compression/stretching;

Rotate through the full circumference.

Use required electrical/insulation/continuity/other tests from the termination procedure. Visual inspection alone may not close the job.

Disposition any suspected nick

If a mark may be a nick:

identify/photograph/location-mark;

prevent termination/energization;

follow cable/project engineering disposition.

wrap tape over it casually;

scrape to see how deep it is;

polish it invisible;

assume continuity proves insulation integrity;

splice without authorization.

The cost of replacing cable is not evidence that a nick is acceptable.

Complete the termination handoff

Keep prepared layers clean and correctly oriented.

Proceed to shield, conductor, connector, gland, seal, crimp, torque, and test steps only under their own verified instructions and tools.

The 90600 is a preparation knife, not a termination system.

Protect the prepared end if work pauses.

Never leave the knife loose beside exposed conductors or inside equipment.

Clean, maintain, and guard

Remove jacket/fill residue through a chemistry compatible with the unknown steel, high-carbon status unresolved, hardwood, and joint.

Inspect the edge after abrasive/filled jackets.

Sharpen only through a qualified geometry-preserving method; no angle/steel/hardness is accepted.

Guard and store dry/secure.

Record recurring cable preparation

cable ID/construction;

deenergization/verification reference;

ring/slit/peel method;

Requalify after cable, lot, temperature/age, strip length, tool/edge, connector, or procedure change.

Control cold, aged, and heat-affected jacket behavior

Jacket condition can change the same construction from yielding to brittle, gummy, bonded, or crack-prone.

Do not heat a cable casually to make stripping easier. Any conditioning temperature/time belongs to the cable manufacturer and workplace method.

On a matching conditioned sample, observe:

whether the score opens cleanly;

whether cracks run beyond the boundary;

whether the jacket stretches instead of releasing;

whether insulation adheres to the jacket;

whether fill migrates;

whether the blade gathers residue;

whether bending exposes age cracks.

If the jacket is aged or heat-damaged, the stripping operation may reveal that the whole cable is unserviceable. Stop for engineering/owner disposition.

Do not call a harder pull or deeper score an acceptable response to changed material.

Prepare branch points and mid-span windows as separate jobs

Removing jacket at a cable end permits peeling toward free space.

A mid-span window or branch preparation has two ring boundaries, no free end, and higher risk of scoring retained jacket/layers. It may require:

dedicated windowing tool;

protected depth stop;

controlled lift tab;

shield continuity method;

minimum bend/service loop;

exact window dimension;

repair/seal system.

Do not extend the end-strip technique to a mid-span window by making two rings and prying between them.

Use the exact cable/termination instruction and its specified equipment.

Keep the knife away from completed electrical surfaces

After jacket removal, the workflow often becomes finer: shield trimming, conductor stripping, cleaning, crimping, sealing.

Park and guard the 90600 when its jacket role is complete.

Do not use it to:

scrape conductor metal;

size a crimp;

open connector seals;

trim braid against insulation;

probe a terminal;

cut heat-shrink on the finished termination;

scrape test points.

Each later operation requires its own controlled tool. Leaving the cable knife live on the bench invites an expedient second use.

Audit repeat stripping by defect location

For repeated ends, map any defect around the cable:

tool entry/exit.

A recurring mark at one clock position may indicate fixture, layer orientation, operator path, or actual cable eccentricity.

Hold the process when the defect trend appears; do not wait for a test failure.

Use a dissected witness at planned intervals under the quality method. Visual confirmation of production ends may not expose beneath-layer scoring.

Release only after documented verification

The stripped end is acceptable only when the applicable criteria are closed:

correct cable identity;

verified energy state/work authorization;

correct strip length;

all retained layers intact;

specified shield/drain/braid condition;

no prohibited nick;

required electrical/insulation/optical test;

inspection signature/record.

What goes wrong (and the fix)

The hardwood handle is treated as insulation. Deenergize, control, and verify.

Catalog/title length conflict is silently resolved. Preserve both as unresolved; do not depend on a printed length.

“13 gauge” is printed beside .072 inch. Remove the gauge; Hyde’s statements conflict.

One hard ring cut reaches insulation. Hold the cable; qualify shallow scoring/peeling.

The cable is held in the fist. Fixture it and direct cuts away.

A bonded jacket is forced off. Follow the exact cable method.

Continuity is used to clear an insulation nick. Apply required insulation/engineering disposition.

Armor is attacked with the knife. Use specified armor equipment.

A local scrap result becomes model capacity. Keep it cable-method specific.

The history footnote

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