A clear cable drawing gives purchasing, engineering, production, and quality teams the same definition of the product. Missing dimensions or undefined tolerances can cause quotation differences, sample delays, assembly variation, and disputes during inspection.
This guide explains the information B2B buyers should include when preparing drawings for custom cables, wire harnesses, molded cables, and industrial cable assemblies.
Overall cable length and tolerance
Define where the overall length is measured: connector face to connector face, cable exit to cable exit, terminal centerline, or another controlled point. State whether the tolerance applies to the complete assembly or individual branches.
Tighter tolerances may require additional fixtures, measurement time, process controls, and cost. Use the functional requirement rather than applying the same tight tolerance to every dimension.
Wire harness branch dimensions
For multi-branch harnesses, identify the main trunk, breakout points, branch lengths, connector orientation, label position, sleeve length, tape wrap, and routing direction. A simple dimension table can make revisions easier to manage.
Connector and terminal definition
- Connector manufacturer and part number
- Mating connector or equipment interface
- Terminal and seal part numbers
- Pin numbering and cavity orientation
- Approved equivalent policy
- Connector color, keying, lock, and secondary retention
Pinout, wire color, and circuit table
Use a circuit table to connect each wire number with the source pin, destination pin, wire gauge, color, marking, and signal or power function. Clearly mark twisted pairs, shield drains, grounds, splices, and unused cavities.
Cut, strip, and crimp requirements
When important to product function, define strip length, conductor exposure, insulation position, crimp height or pull-force requirement, soldering requirement, and inspection standard. Terminal supplier specifications can be referenced when available.
Overmold and strain-relief dimensions
Specify overmold envelope, connector exit direction, logo or text, color, hardness preference, minimum bend clearance, and equipment installation limits. If the overmold must fit through an opening, include the opening dimensions and assembly sequence.
Electrical and functional testing
- Continuity and short-circuit test
- Insulation resistance or dielectric withstand where required
- Contact resistance or voltage-drop requirement
- Shield continuity and grounding
- Data, charging, sensor, or equipment functional test
- Test fixture or mating equipment supplied by the buyer
Cosmetic and workmanship criteria
Define acceptable appearance for jacket marks, mold lines, color variation, label alignment, exposed conductor, terminal damage, braid coverage, adhesive, tape overlap, and connector scratches. Reference photos are useful when appearance is important.
Packaging and labeling instructions
Include coil diameter, protective caps, cable ties, individual bags, quantity per carton, barcode content, serial or lot number, private label artwork, carton marks, pallet requirements, and moisture protection.
Drawing revision and approval control
Every drawing should have a part number, revision, date, owner, and change description. Sample approval should reference the approved revision. Production should not begin from an informal image or an outdated attachment when a controlled drawing exists.
Recommended RFQ drawing package
- Assembly drawing and circuit table
- Connector and terminal references
- Electrical and mechanical requirements
- Testing and inspection criteria
- Quantity, forecast, and delivery date
- Packaging, labels, and destination market
- Reference sample or equipment photos where useful
Nexharn can review incomplete drawings and identify missing quotation information before sampling. See the cable materials guide, review the manufacturing process, or upload your drawing for review.