Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
A crimped terminal is the standard way to attach a ring, spade or butt connector to a 12 V wire, for a car audio install, a boat, an RV, a solar setup, or similar low-voltage accessory wiring. Done well, a crimp is a permanent joint that outlasts the equipment it is in. Done with the wrong tool, it can look fine and pull apart months later, once vibration and flexing find the weak point. This page walks through stripping the wire, choosing a matched terminal and tool, making the crimp, examining it, and proving the joint with a pull test before you trust it.
Every terminal maker publishes its own wire range, crimp die and pull-out force for its terminal families, and those numbers do not carry over from one brand to another. This page does not guess a number for your terminal: it shows you the method, and tells you where to read the number that applies to the part in your hand. It also does not cover fixed building wiring, or connecting the finished lead to a battery or a circuit — those are separate jobs.
Safety
DISCONNECT THE WIRE FROM ITS BATTERY OR POWER SOURCE BEFORE YOU START.
A stripped strand can touch a grounded part and burn you.
Necessary equipment
| Item | Note |
|---|---|
| Wire strippers | The strippers must match the wire gauge. |
| Wire cutters optional | Use the cutters to cut the wire to length before you strip it. |
| Ratcheting crimp tool | The tool must match the terminal. Do not use pliers to crimp a terminal. |
| Safety glasses | Wear the glasses when you cut or strip the wire. |
| Permanent marker or wire labels optional | Label the finished lead, if your project needs it. |
| Crimp terminal (ring, spade or butt connector) material | The terminal must match the wire gauge and the connection you need. |
| 12 V accessory wire material | The wire must carry the current the circuit needs. |
Before you start
Estimated 2 min to 3 min
- Gather the wire, the terminal, and the tools for this procedure.1mReport a problem with step 1, Before you start
- The terminal must match the wire gauge and the connection.
- The crimp tool must match the terminal, not a pair of pliers.
- Disconnect the wire from its battery or power source.<1mReport a problem with step 2, Before you start
- Read the wire gauge from the wire insulation or the equipment manual.<1mReport a problem with step 3, Before you start
Select the terminal and the tool
Estimated 2 min to 2 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Select a terminal that matches that wire gauge.1mReport a problem with step 1, Select the terminal and the tool
- The terminal package states the wire range.
- The manufacturer's application specification also states the wire range.
- Select a crimp tool that matches that terminal.<1mReport a problem with step 2, Select the terminal and the tool
- A tool from the terminal's own maker gives the most reliable crimp.
Strip the wire
Estimated 1 min to 3 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
WEAR EYE PROTECTION BEFORE YOU CUT OR STRIP THE WIRE.
A cut strand can fly into your eye and injure it.
- Strip the insulation from the end of the wire.<1mReport a problem with step 1, Strip the wire
- Strip to the length the terminal manufacturer specifies.
- Set the wire stripper to the correct gauge for a clean strip.
- Examine the bare strands for a nick or a cut.<1mReport a problem with step 2, Strip the wire
- Remove a nicked or cut strand from the wire end.<1mReport a problem with step 3, Strip the wire
- After you remove the damaged strand, strip the wire again.
Crimp the terminal
Estimated 1 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Insert the bare strands into the wire barrel of the terminal.<1mReport a problem with step 1, Crimp the terminal
- Push the wire into the barrel until the strands show at the far end.
- The insulation goes into the insulation barrel, next to the wire barrel.
- Place the terminal in the correct cavity of the crimp tool.<1mReport a problem with step 2, Crimp the terminal
- If the tool uses a colour code, match the terminal's colour to the tool's colour.
DO NOT CRIMP A TERMINAL WITH PLIERS OR AN UNMATCHED TOOL.
The wrong tool does not form the correct crimp shape. The joint can loosen later.
- Squeeze the tool handles together fully.<1mReport a problem with step 3, Crimp the terminal
- A ratchet tool does not open until the crimp cycle is complete.
- Remove the crimped terminal from the tool.<1mReport a problem with step 4, Crimp the terminal
Examine the crimp
Estimated 3 min to 6 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Examine the wire barrel for the bare strands.<1mReport a problem with step 1, Examine the crimp
- The strands must show at the open end of the barrel.
- The strands must not extend past the open end.
- Examine the insulation barrel for the wire insulation.<1mReport a problem with step 2, Examine the crimp
- The insulation must sit inside the insulation barrel.
- Examine the terminal body for a crack, a twist, or a bend.<1mReport a problem with step 3, Examine the crimp
- Discard a terminal that does not pass examination. Crimp a new terminal on the wire.1mReport a problem with step 4, Examine the crimp
- Pull firmly on the wire by hand.<1mReport a problem with step 5, Examine the crimp
- Hold the terminal in one hand and the wire in the other.
- A correctly crimped wire does not move or pull free.
- If the wire moves or pulls free, discard the terminal. Crimp a new terminal on the wire.1mReport a problem with step 6, Examine the crimp
Finish
Estimated under a minute to 1 min
- If your project needs a label, attach one to the finished lead.<1mReport a problem with step 1, Finish
- Store the finished lead until you are ready to connect it.<1mReport a problem with step 2, Finish
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- crimp terminal
- Also called: crimp connector, wire connector, electrical terminal, crimp lug, wire crimp, terminal connector
- ring terminal
- Also called: ring connector, eyelet terminal, ring lug, ring tongue terminal, loop terminal
- spade terminal
- Also called: fork terminal, spade connector, flanged spade connector, U-terminal
- butt connector
- Also called: butt splice, wire splice connector, inline wire connector
- ratcheting crimp tool
- Also called: crimping tool, crimping pliers, ratchet crimper, terminal crimper, wire crimper
- pull test
- Also called: tug test, crimp test, pull-out test, yank test
- wire barrel
- Also called: crimp barrel, conductor barrel, terminal barrel
When to use a professional
This procedure covers a crimped connection on 12 V accessory or battery-isolated wire. It does not cover fixed building wiring or a circuit inside a wall.
Consult a qualified electrician for building wiring. Consult a qualified installer for a wiring task inside a vehicle's main battery or starter circuit.
This procedure does not state a wire gauge, a crimp die, or a pull-out force for your terminal. Read those values from the terminal package or the manufacturer's application specification.
This procedure ends before you connect the finished lead to a battery or a circuit. Follow the equipment manufacturer's instructions for that connection.
Common questions
Why did my crimp connector come off?
The two most common causes are the wrong tool and no test. A pair of pliers pinches a terminal at two points instead of forming it evenly around the wire, so the joint can look closed while the strands inside are barely gripped. TE Connectivity's own guidance on crimping is direct: tool and terminal should come from the same maker, because a mismatched tool leaves defects that are often invisible to the naked eye. A firm pull test on a fresh crimp catches most of these joints before they are ever put into service, which is exactly why this page treats the pull test as a required step, not an optional one.
Can I crimp a wire with regular pliers instead of a crimp tool?
Not reliably. A crimp tool is built with dies shaped to compress the terminal's wire barrel evenly around the strands, and a ratcheting tool will not release until a full crimp cycle is complete. Ordinary pliers do neither: they squeeze at one or two points, can distort the terminal, and let you stop partway through. The joint may look fine right after you make it and still fail once the wire flexes or vibrates.
How do I know what size crimp connector I need for my wire?
Read the wire gauge (AWG) printed on the wire jacket, or listed in your equipment's manual, then match it to the wire range printed on the terminal's own package. Many insulated terminals use a colour on the sleeve as a quick visual guide — TE Connectivity's own training material shows red, blue and yellow covering roughly the 22-18, 16-14 and 12-10 AWG ranges on its standard product line — but the exact boundary differs between terminal families and manufacturers, so treat the colour as a hint and the package or the application specification as the answer.
What's the difference between a ring terminal, a spade terminal, and a butt connector?
A ring terminal has a closed loop that goes over a stud or a bolt and cannot slip off once the fastener is tight, which is why it is the usual choice for a battery post or a chassis ground. A spade (or fork) terminal has an open U-shape that slides under a loosened screw or stud without removing the fastener completely, but it can work loose if that fastener backs off. A butt connector joins two wire ends inside one barrel and is used to splice or extend a wire rather than to terminate it at a stud or a screw.
How hard should I pull to test a crimp?
There is no single number to aim for by hand, and this page does not print one: a terminal manufacturer's own minimum pull-out force is specific to that terminal family and is measured in a lab with a calibrated tensile-testing machine, not by feel. The practical field version is qualitative: grip the terminal in one hand and the wire in the other, and pull firmly. A correctly crimped wire will not move or slide out at all. If it shifts even slightly, or comes free, the crimp has failed and the terminal should be discarded rather than reused.
Do I need a special tool for each brand of terminal, or will any crimper work?
TE Connectivity's own literature is blunt that a crimp performs to specification only when the tool and the terminal come from the same maker, since the dies are engineered to that terminal's exact geometry. In practice, a decent ratcheting crimper sized to your wire gauge will produce an acceptable crimp on many common insulated terminals that share the same colour-coded system, but if the connection matters — a battery lead, a high-current accessory circuit — use the tool the terminal manufacturer specifies for that terminal family.
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Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
- Tier 1Quick Reference Guide: PIDG Terminals & Splices
- Tier 1The Simple Guide to Crimping: Solderless Closed Barrel Termination Training Manual
- Tier 1Crimping Terminals: The Importance of Using the Right Tool
- Tier 1Instructions: Ratcheting Ferrule Crimpers (Catalog No. 34055, 34056)
Revision history
Current version 1 · updated 2026-08-04 · next review due 2027-08-04
- v1 · 2026-08-04First draft. Method (strip, select, crimp, examine, pull-test) is synthesised from four tier-1 manufacturer sources, each fetched and read directly on 2026-08-04: TE Connectivity's 'Quick Reference Guide: PIDG Terminals & Splices', TE Connectivity's 'The Simple Guide to Crimping' training manual, TE Connectivity's 'Crimping Terminals: The Importance of Using the Right Tool' white paper, and Klein Tools' instruction sheet for its ratcheting ferrule crimpers (34055/34056). No competitor or aggregator page was opened at any point (brief 1.5); the four sources above are the only pages read. NASA-STD-8739.4A ('Workmanship Standard for Crimping, Interconnecting Cables, Harnesses, and Wiring') was also fetched and read in full, including its crimp pull-force tables (Table 12-1, Table 13-1), but is deliberately NOT cited: paragraph 1.2.2 states the standard applies to 'production and processing of mission hardware' under NASA contracts, and its pull-force values are measured with a calibrated tensile-testing device on aerospace-qualified contacts, not on the automotive/consumer ring, spade and butt terminals this page covers. Borrowing those numbers here would be exactly the kind of quantity mismatch this repository's sourcing rules exist to prevent, so the pull-test step is written qualitatively (does the wire move at all) instead. Every numeric specification a reader could apply to the wrong terminal family — wire gauge range, strip length, crimp die/height setting, minimum pull-out force — publishes as an instruction to consult the terminal manufacturer's own package or application specification, per the backlog entry's sourcing note that these values are per terminal family and do not generalise; only the method and the pull test publish general. The red/blue/yellow insulation colour convention is mentioned only in the FAQ, in hedged language, because TE's own tables (Quick Reference Guide vs. Simple Guide to Crimping) show the exact AWG boundary for each colour differs between terminal families, so it is not treated as a single verified specification. Scope is deliberately narrow: 12 V accessory and battery-isolated wiring only, with the wire disconnected from any battery or power source before work starts (page-level hazard), which keeps the record out of config.json's mains-voltage and live-circuit deferred territory. The page explicitly excludes fixed building wiring and connection of the finished lead to a battery or a circuit, routing both to the professional_boundary. Sources are staged in data/sources-additions-crimp-and-check-a-low-voltage-electrical-terminal.json and are not yet admitted to data/sources.json; check 3 will hold this record until scripts/sources_admit.py runs.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.