Open Barrel & Weather Pack Crimpers

A proper crimp is a cold-welded mechanical bond. Achieving this requires precise geometry that folds the terminal wings over the wire strands (the core crimp) and separately around the insulation (the strain relief), rolling them tightly into a 'B' or 'W' shape.

The Mechanics of a "B-Crimp"

Standard open-barrel terminals (found in almost all OEM connectors like Metri-Pack, GT 150, and unsealed relays) require an F-crimp or B-crimp profile. The die must precisely fold the two tangs inward and downward, compressing the copper strands until all voids are eliminated, creating a gas-tight seal.

Required Features in a Crimper

  • Ratcheting Mechanism: Ensures the tool completes the full crimp cycle before releasing. This prevents under-crimping by user fatigue.
  • Machined Dies: Stamped dies lack the precise tolerances needed. Look for EDM (Electrical Discharge Machining) cut dies.
  • Compound Leverage: Applies massive force with minimal hand pressure.

Specific Tools by Connector Type

Weather Pack

Weather Pack terminals have round pins/sockets and require a very specific die that curls the wire wings and wraps the insulation wings perfectly around the ribbed silicone seal in a single operation. Tool requirement: Delphi/Aptiv 12014254 or equivalent high-quality aftermarket ratcheting tool specifically labeled for Weather Pack.

Metri-Pack (150/280/480)

These utilize a classic open-barrel B-crimp for the wire, and overlapping wings for the insulation (or a seal). Because the terminals are different sizes, a multi-cavity die is usually required. Tool requirement: Delphi 12085271 (for unsealed) or equivalent.

Deutsch DT/DTM

Solid Deutsch contacts require a 4-way indent crimper (like the HDT-48-00). Stamped and formed Deutsch contacts use a specialized open-barrel B-crimp. Do not mix the tooling.

Crimp Pull-out Force Standard

Common Mistakes

1. Using "Pliers" style crimpers. Standard automotive parts-store crimpers flatten the terminal rather than rolling the wings. This results in weak pull-out strength and high electrical resistance.

2. Over-crimping. Using a die cavity meant for a smaller wire gauge will extrude the copper out the sides, thinning the terminal material and causing micro-fractures in the copper strands.