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Custom Cable Assembly RFQ Checklist: What to Include for an Accurate Quote

August 3, 2026

An accurate custom cable assembly quote depends on more than part numbers and estimated quantities. Manufacturers must understand what the assembly connects, how it will be installed, which conditions it must withstand and what inspection, testing and documentation the program requires.

The stronger your request for quotation, or RFQ, the easier it is to compare suppliers and identify differences in materials, tooling, testing and production assumptions.

You do not need every specification finalized before contacting a manufacturer. A complete drawing and bill of material are helpful, but an experienced engineering-supported manufacturer can often begin with a sample, wiring diagram, connector list, photographs or a description of the application.

The key is to distinguish confirmed requirements from details that still need to be developed.

Have a Cable Assembly Project to Quote?

Use XACT’s Cable Assembly Configuration Tool to submit the specifications you know, identify open requirements and upload supporting files for review.

1. Begin With the Application

Start by explaining what the cable assembly will do. A list of connectors and conductor sizes does not tell the manufacturer how the assembly will be used or which failure risks matter most. Two assemblies with similar electrical configurations may require very different construction if one is installed inside protected equipment and the other is exposed to vibration, chemicals, moisture or repeated movement. include:

Equipment or system type
General function of the assembly
Installation location
Indoor or outdoor use
Protected or exposed installation
Stationary or moving application
Expected service lifes
Accessibility for maintenance or replacement
Consequences of failure

This context helps the manufacturer identify missing requirements and evaluate whether the proposed materials and construction are appropriate. For an existing assembly, explain what currently works and what needs improvement. Common concerns may include connector failures, water ingress, abrasion, insufficient strain relief, difficult installation, premature flex damage or long replacement lead times. XACT’s configuration tool includes fields for the installation or equipment type, environmental conditions, flexing versus static use and desired improvements to an existing design. Details that are not known can be left blank or explained in the open-text fields.

2. Identify Whether the Design Is New or Existing

Tell the manufacturer whether the RFQ involves:

A new assembly
A build-to-print production package
A redesign of an existing assembly
A replacement for an obsolete product
A reverse-engineered assembly
A prototype requiring further development
A production transfer from another supplier

For an existing design, provide its revision status and clarify whether changes are permitted. A manufacturer should not assume that an existing assembly is optimized simply because it has previously been produced. It may contain unavailable components, unnecessary complexity, weak strain relief, difficult-to-control dimensions or requirements that were never formally documented. For a new design, identify which decisions are already established and which require engineering input.

Starting Without a Production-Ready Drawing?

XACT can review application requirements, existing samples, partial specifications and available design files to help define a manufacturable approach.

3. Provide Drawings, Wiring Diagrams or Pinouts

A controlled drawing is one of the most useful RFQ documents because it can define:

Overall assembly length
Branch lengths and breakout locations
Connector orientation
Pin-to-pin wiring
Wire gauges and conductor colors
Shielding requirements
Labels and identification
Tolerances
Notes and workmanship requirements
Drawing revision
Approval status

When a formal drawing is unavailable, send whatever information exists. That may include:

Wiring diagram
Pinout table
Hand sketch
Marked-up photograph
Connector datasheets
Equipment schematic
Existing sample
Prior supplier drawing
Installation measurements

Clearly identify any dimensions that are approximate rather than controlled. Do not rely on photographs alone when pin assignments, polarizations or critical dimensions cannot be seen. Use them as supporting references, not substitutes for electrical and dimensional requirements.

4. Include the Bill of Material When Available

A bill of material, or BOM, should identify the approved components and materials used in the assembly.

Relevant entries may include:

Bulk cable
Individual wires
Connectors
Contacts
Backshells
Seals
Boots
Terminals
Splices
Tubing
Sleeving
Braid
Heat-shrink
Labels
Overmolding materials
Potting compounds
Fasteners and mounting hardware

For each item, include the manufacturer and part number when required.

Also state whether substitutions are:

Prohibited
Allowed with written approval
Allowed for equivalent commercial components
Expected to be recommended by the manufacturer

This matters because a lower-cost quote may be based on alternatives that do not match the original specification. Suppliers should not independently replace controlled components without approval.

When a BOM is incomplete, identify any mandatory components and ask the manufacturer to recommend the remaining materials based on the application.

5. Define the Electrical Requirements

Include the electrical characteristics the assembly must support, not just the wire gauge.

Depending on the application, this may include:

Operating voltage
Maximum current
Signal type
Data or communication protocol
Frequency range
Impedance requirements
Conductor resistance limits
Shielding requirements
Grounding approach
Isolation requirements
Circuit identification
High-voltage separation
Maximum allowable voltage drop

Specify whether power, control and data circuits share the same assembly.

If shielding is required, define what it is intended to protect against and how it should be terminated. “Shielded cable” alone may not establish whether the shield is connected at one end, both ends, through a backshell or through a separate drain conductor.

6. Define the Mechanical Construction

The RFQ should describe how the assembly must fit, route and connect within the equipment.

Include:

Overall length
Branch lengths
Breakout locations
Length tolerances
Minimum bend radius
Connector orientation
Right-angle or straight exits
Mounting points
Clamps or retention features
Maximum diameter
Space restrictions
Pulling or installation constraints
Required flexibility
Repeated flexing or torsion
Minimum strain-relief length

Explain whether the assembly will be installed once and remain stationary or move continuously during operation.

For molded assemblies, provide the available envelope around each connector or breakout. The manufacturer needs enough clearance to develop an overmold that fits the equipment while providing suitable strain relief and protection.

Contextual references:

7. Describe the Operating Environment

Environmental requirements influence cable compounds, connector selection, sealing, protective coverings and validation methods.

Identify expected exposure to:

High or low temperatures
Temperature cycling
Water spray
Temporary or continuous submersion
Oil, fuel or hydraulic fluid
Cleaning chemicals
Dust and debris
UV exposure
Abrasion
Impact
Vibration
Flexing
Salt fog
Pressure
Outdoor weather
Hazardous locations

Use actual operating ranges or referenced specifications when available.

Avoid vague terms such as:

Weatherproof
Waterproof
Rugged
Heavy duty
Chemical resistant
High temperature

These terms do not establish measurable acceptance criteria. “Waterproof,” for example, could refer to incidental splash exposure or prolonged submersion at a defined depth and duration.

If the requirement is still being developed, describe the real installation conditions and ask the manufacturer what additional information is needed.

Building for a Demanding Environment?

Review XACT’s custom cable assembly capabilities for applications involving overmolding, shielding, environmental protection and ruggedized construction.

8. State the Required Workmanship Standards

Identify any workmanship or program standards that must apply.

IPC/WHMA-A-620 establishes requirements and acceptance criteria for cable and wire harness assemblies, including crimped, mechanically secured and soldered interconnections and related assembly activities. It does not replace the need to define the product’s design, inspection frequency, testing and application-specific requirements in the purchasing documentation.

Your RFQ should state:

Applicable standard and revision
Required class or acceptance level
Customer-specific workmanship requirements
Applicable addenda
Required operator qualifications
Inspection requirements
Source inspection requirements
Any conflicts between the drawing and referenced standards

Do not list standards simply because they sound relevant. Apply them only when required by the program, customer or product risk.

Buyers should also distinguish a quality-management-system certification from product-specific acceptance requirements. ISO 9001 provides a framework for managing consistent processes and meeting customer and regulatory expectations, but it does not prescribe the design or acceptance criteria for a particular cable assembly.

9. Define Testing and Validation Requirements

Do not request “100% testing” without defining which tests must be performed.

Possible production or qualification tests include:

Point-to-point continuity
Short-circuit detection
Insulation resistance
Dielectric withstand
Contact resistance
Pull testing
Functional testing
Leak or ingress testing
Flex-cycle testing
Temperature testing
Vibration testing
Signal-integrity testing
Customer-defined test procedures

State:

Which tests apply to every assembly
Which tests apply only to prototypes or first articles
Required test limits
Test duration
Test voltage or current
Fixture requirements
Pass/fail criteria
Whether measured results must be retained
Whether reports must be supplied
Whether testing must be tied to a serial number or lot

Testing costs can vary substantially depending on whether the manufacturer is performing basic continuity verification, developing a dedicated fixture or coordinating external environmental qualification.

XACT’s Cable Assembly Configuration Tool lets users identify IPC/WHMA-A-620, military standards, custom testing requirements, first-article needs and special certifications or approvals.

Related reading: How XACT Uses Vacuum Submersion Leak Testing

10. Specify Labeling, Marking and Traceability

Define how the assembly and its branches must be identified.

Requirements may include:

Part-number labels
Revision identification
Serial numbers
Lot numbers
Connector identifiers
Branch labels
Circuit markers
Orientation markings
Date codes
Customer asset numbers
Barcodes or machine-readable labels

Include label content, location, orientation, material and durability requirements when controlled.

Also define the required traceability and documentation, such as:

Material lot traceability
Component lot traceability
Build travelers
Inspection records
Test records
Certificates of conformance
First-article reports
Calibration records
Deviation approvals
Revision history

These requirements affect production labor, systems and record retention, so they should be included before pricing.

11. Provide Prototype and Production Quantities

A quote should distinguish among:

Engineering prototypes
First-article units
Pilot production
Initial production order
Expected annual usage
Maximum release quantity
Spare or replacement demand

Do not provide only an estimated annual quantity when the first order will be much smaller.

Suppliers may use different manufacturing methods, tooling and pricing structures for five prototypes than for 5,000 recurring units. Providing both initial and expected production quantities helps the manufacturer recommend an appropriate process.

Also state:

Expected order frequency
Forecast visibility
Blanket-order requirements
Inventory or stocking expectations
Program duration
Expected demand variability

12. Separate the Quote Deadline From the Delivery Requirement

“Need quote by” and “required delivery date” are different requirements.

Your RFQ should include:

Date the quote is required
Date prototypes are required
Date production is required
Whether the delivery date is fixed or preferred
Whether partial deliveries are acceptable
Required shipping location
Expediting expectations

Avoid requesting an immediate quote while leaving no time for engineering review. Complex assemblies may require the manufacturer to clarify specifications, obtain component pricing, evaluate tooling and determine test requirements before providing a responsible quotation.

A fast quote based on unverified assumptions is not necessarily a better quote.

13. Identify Tooling and Nonrecurring Requirements

Some programs require one-time investments in:

Overmold tooling
Assembly fixtures
Test fixtures
Programming
Engineering development
Drawings
First-article documentation
Custom packaging
Specialized crimp tooling

Ask suppliers to separate nonrecurring engineering and tooling costs from unit pricing.

Also clarify:

Who owns the tooling
Where it will be stored
Whether maintenance is included
Expected tooling life
Whether replacement tooling is chargeable
Whether the tooling can be transferred
Which design files or documentation will be delivered

This prevents comparisons in which one supplier includes development and tooling while another excludes them.

14. Include Packaging and Delivery Requirements

Packaging can affect both quality and cost, particularly for long, delicate, labeled or contamination-sensitive assemblies.

Specify whether the assemblies require:

Individual bags
Protective caps
Coiling diameter controls
Reel packaging
Custom trays
Moisture protection
Desiccant
Clean packaging
Branch separation
Connector protection
Kit packaging
Customer-specific labels
Export packaging

Also state whether assemblies must be delivered individually, in kits or grouped by installation location.

15. Upload the Most Useful Supporting Files

Include the clearest current version of every relevant document.

Useful files may include:

Controlled drawings
BOMs
Wiring diagrams
Pinout tables
Connector specifications
Equipment drawings
Installation photographs
Images of the existing assembly
Customer specifications
Test procedures
Inspection requirements
Packaging instructions
Forecasts
Samples or prior failure reports

Use clear file names and revision identifiers. Do not send several conflicting versions without identifying which one controls the quote.

When sending photographs, include a reference scale and show connector interfaces, branch points, labels and damaged areas when relevant.

Custom Cable Assembly RFQ Checklist

Before submitting the request, confirm that you have addressed the following:

Project and Application

New or existing design
Equipment type and assembly function
Installation location
Current design concerns
Static or flexing use

Technical Package

Drawing, sketch or sample
Wiring diagram or pinout
BOM or approved components
Electrical requirements
Mechanical dimensions and tolerances
Connector orientation
Labeling requirements
Substitution policy

Environment

Temperature range
Moisture or submersion
Chemical exposure
UV exposure
Vibration and impact
Abrasion
Flexing or movement
Required sealing or protection level

Quality and Testing

Workmanship standards
Inspection requirements
Production tests
Qualification tests
First-article requirements
Certifications or approvals
Traceability and documentation

Commercial Requirements

Prototype quantity
Initial production quantity
Expected annual usage
Quote deadline
Required delivery date
Packaging requirements
Shipping location
Tooling and nonrecurring-cost expectations

You do not need every item finalized to begin. Identify what is known, what is approximate and what requires supplier input.

Common RFQ Mistakes

Avoid these frequent problems:

Providing a connector list without a pinout
Giving annual usage without the initial order quantity
Describing the assembly as “rugged” without defining the environment
Requesting testing without pass/fail criteria
Omitting the drawing revision
Sending conflicting files
Failing to identify mandatory components
Leaving substitution rules unclear
Treating the quote deadline as the delivery date
Omitting tooling and first-article requirements
Assuming documentation is included automatically
Asking for a firm production price while major design decisions remain open

A quote based on incomplete information may still be useful for budgeting, but it should be clearly identified as preliminary and subject to revision.

Submit a Stronger Cable Assembly RFQ

A useful RFQ does not need to answer every engineering question. It must give the manufacturer enough context to understand the application, identify risk, expose assumptions and determine what still needs to be resolved.

XACT’s Cable Assembly Configuration Tool is designed for this early scoping stage. Users can select known build, manufacturing, termination, environmental and protection requirements; add engineering notes; and upload supporting files. XACT’s engineering team can then review the information and follow up on missing details.

Configure Your Cable Assembly With XACT

Share your known specifications, application requirements and available files. XACT can review the project for engineering fit, manufacturing approach, testing needs and quotation requirements.

FAQ

Do I need a completed drawing to request a cable assembly quote?

No. A completed drawing is useful, but many projects can begin with a sample, pinout, wiring diagram, BOM, connector list, photographs or application requirements. The manufacturer may need additional engineering work before providing firm production pricing.

View XACT’s complete certifications and accreditations.