Crimping Tools

Choosing the right crimping tools

A crimp is only as good as the match between the die and the terminal. Each terminal family has its own barrel shape, so a tool made for open barrel JST pins will not properly close a machined Deutsch contact, and a battery lug needs far more force than a small signal wire crimper can deliver. Start with the terminal you are using, confirm your wire gauge, then choose the tool built for that combination.

Crimping tool selection table

Matching the crimper to the terminal

Deutsch crimpers: solid or stamped contacts

Deutsch contacts come in two styles. Solid, machined contacts need a closed barrel crimper with a positioner to locate the contact, which is what the IWD series and HD-2612D are built for. Stamped contacts are formed from sheet metal and take an open barrel style crimp, so confirm your contact style and check the product page before buying.

The IWD crimpers are sold by contact size: size 12, size 16 for 14 to 18 gauge and size 20 for 20 to 22 gauge. Working across Deutsch, Weather Pack and open barrel terminals? The Kit-DC01 covers all three.

Weather Pack and Metri-Pack

These sealed automotive terminals have rear wings that close over a rubber cable seal as well as front wings for the conductor, so the die has to form both properly for the connection to stay weather tight. The IWS-1424B is dedicated to this job.

JST, Molex and other open barrel pins

These small pins sit inside the plastic housings found on printer mainboards, drones, RC gear and automotive sensors. Choose by gauge: the IWS-2820M suits the smallest pins such as JST XH and Molex KK, the IWS-1442L spans AWG 30-14, and the IWS-2412M handles open barrel and flag terminals up to AWG 12 with adjustable crimping force.

Ferrules and the ratchet crimping tool

Ferrules gather stranded wire into a solid end that clamps securely in screw terminals on control panels, power supplies and controllers. The HSC8 ratchet crimping tool forms a square crimp with four serrated crimp surfaces.

Battery lug crimpers

Heavy cable in solar battery banks, RV and caravan systems, marine and 4WD dual battery setups, and welding leads needs a lug crimper with serious leverage. The compact IWS-0670C punch type tool makes a deep indent crimp on copper and aluminium lugs and works well in tight spaces. The IWS-0801C covers heavy duty copper lugs, and the long handled IWS-1040S takes the largest battery cable up to 4/0.

Stripping wire to the right length

Many bad crimps start at the stripping stage. Strip too much and bare copper sticks out past the barrel where it can short. Strip too little and the conductor wings bite into insulation instead of copper. The goal is a conductor that fills the wire barrel with the strand ends just showing at the front, and insulation that reaches into the insulation grip. The terminal maker's data sheet gives exact strip lengths.

• Never nick or cut strands, because every lost strand reduces the conductor's capacity.
• The FSA-0626/B wire strippers come in AWG 30-20 for fine signal wire and AWG 22-10 for heavier leads.
• The HS-D2 self-adjusts to the wire and also cuts and crimps.
• For ferrules, strip so the conductor fills the full length of the metal sleeve.
• For solid Deutsch contacts with an inspection hole, the conductor should be visible in the hole.

How to check crimp quality

• Pull test: give every crimp a firm tug. If the wire moves or slides out, cut it off and start again.
• Bellmouth: on open barrel terminals, look for a slight flare at the front edge of the conductor crimp. It shows the terminal sat correctly in the die and keeps the barrel edge from cutting strands.
• Conductor position: strand ends visible just past the barrel, and no insulation caught under the conductor wings.
• Insulation support: the rear wings should grip the insulation firmly for strain relief without cutting through it.
• Appearance: an even, symmetrical crimp with no cracks, split wings or stray strands.

Where these crimping tools get used

• Automotive, 4WD and marine: Deutsch and Weather Pack harnesses for lighting, sensors and accessories.
• Solar and RV: lugs on house batteries and inverter cables, plus ferrules for screw terminal connections.
• E-bikes and scooters: small signal plugs for displays and sensors, alongside XT and MT60 power connectors.
• Robotics, drones and 3D printers: micro connector pins on controller boards, motors, fans and endstops.

Disconnect the battery or power supply before working on any system, keep fingers clear of the jaws, and wear eye protection when cutting heavy cable. In Australia, mains voltage wiring must be done by a licensed electrician.

Buying crimping tools from OzFDM

Every Iwiss tool here is held in Australian stock and dispatched from our Perth or Melbourne warehouse. Workshops, schools and businesses can apply for a trade account, and orders over $299 qualify for free shipping Australia-wide, excluding PO Boxes.

Crimping tool FAQs

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