Cable Harness Workmanship Acceptance: IPC/WHMA-A-620 Revision, Class and RFQ Evidence

Build to IPC/WHMA-A-620 sounds precise, yet it leaves critical purchasing decisions unanswered: revision, class, applicable supplements, contractual precedence, inspection frequency, evidence, rework limits and requirement flowdown. A standard citation alone does not prove the manufacturing site, personnel authorization, product configuration, inspection and test records, or acceptance of a particular shipment.

Direct answer: use IPC/WHMA-A-620 as one controlled layer of a complete acceptance package. State the exact revision, customer-selected class, applicable supplements, requirement precedence, drawing and BOM revisions, inspection and test plan, evidence delivery, deviation route and change controls. Confirm individual credentials and organization or site qualifications as separate claims, then accept product only against traceable records for the ordered configuration.

This article helps B2B buyers turn a workmanship reference into an auditable RFQ for battery cables, cable harnesses and related electrical assemblies. It does not reproduce copyrighted acceptance criteria or select a class for a product. It makes no claim about a SINAWATTS certification, qualified site, employee credential, manufacturing capability, material, test capability, stock, price, MOQ, lead time or customer result. Confirm every such point in the product-specific quotation and controlled evidence.

Start with the current document identity

The official IPC document revision table, checked on 2026-10-08, lists IPC/WHMA-A-620 Revision F, October 2025 as the current base revision. The official IPC/WHMA-A-620F table of contents identifies sections for classification, definition of requirements, process control, order of precedence, requirements flowdown, personnel proficiency, acceptance requirements and inspection methodology.

Those public records establish document identity and subject coverage. They do not provide the acceptance details in the licensed standard and do not authorize a buyer or supplier to reconstruct requirements from photographs, older training slides or internet summaries. At RFQ release, record:

• full standard designation and revision;
• agreed product class, selected by the responsible customer or design authority;
• applicable sector addendum, if any, with a compatible revision;
• language or controlled translation used by the parties;
• customer drawings, specifications and approved parts lists;
• terminal, connector, splice, wire and tooling manufacturer specifications;
• deviations, exceptions and specially agreed criteria;
• governing product, regulatory or installation requirements; and
• a precedence statement for conflicts.

Do not write “latest revision applies” without a change mechanism. A quotation can be prepared under one revision and produced after a new revision appears. Define the frozen contractual baseline and state whether later revisions require written review, automatic adoption or no change until the buyer approves a revision impact assessment.

Separate six different claims

Procurement records often compress several claims into “IPC certified.” Separate them before comparing suppliers.

On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.

The official IPC certifications page, checked on 2026-10-08, describes certification programs for individuals who complete the applicable training and testing. The official IPC/WHMA-A-620 Qualified Manufacturers List page describes a separate program used to qualify listed EMS and OEM providers' assembly processes to IPC standards, with named locations, classes and listing dates. Neither claim alone proves that a particular shipment conforms to the buyer's released product requirements.

Define the contractual hierarchy before judging workmanship

A workmanship standard cannot resolve an unclear design. The customer must freeze the intended harness before visual acceptance can be meaningful. The technical package should include:

• released schematic and connection table;
• wire list with manufacturer or controlled material specification, size, conductor construction, insulation and color;
• terminal and connector manufacturer part numbers and revisions;
• seal, cavity plug, wedge lock, TPA, CPA, backshell, boot, clip and accessory identities;
• splice definition, branch geometry and breakout locations;
• cut length, finished length, tolerance datums and measurement condition;
• strip length, crimp specification and tooling identity from the component manufacturer;
• solder, ultrasonic weld, ferrule, lug or other termination requirements where used;
• labels, orientation, text, barcode content and durability requirements;
• sleeving, braid, conduit, tape, heat-shrink and overmold details;
• electrical tests and product-specific limits;
• environmental, mechanical and service conditions; and
• packaging, bend restraint and connector protection.

The RFQ should then state the agreed precedence when these sources differ. A common controlled hierarchy can place the purchase order and approved customer drawing above referenced workmanship criteria, followed by approved component application specifications and supplier work instructions, but the actual hierarchy must be agreed for the project. Do not assume a universal order from this article. Ask the supplier to flag conflicts before production rather than silently choose the easiest requirement.

The battery-cable first-article and change-control guide explains how to freeze drawing, BOM, process and inspection evidence at the first-article stage. The workmanship plan in this article begins from that controlled product definition.

Know what the public IPC scope does and does not supply

The official IPC Meet Your Standards page, checked on 2026-10-08, describes IPC/WHMA-A-620F as providing process and acceptance requirements for cable and harness assemblies. It says the standard covers materials, methods, tests and acceptability criteria for crimped, mechanically secured and soldered interconnections and related assembly activities. The same page states important limits: the standard does not provide cross-section or X-ray criteria; it does not specify the frequency of in-process or product inspection; and it places no limit on the number of process indicators or allowable repair or rework of defects.

These boundaries change the RFQ. A buyer that needs microsection measurements, X-ray criteria, first-and-last-piece checks, hourly inspection, one sample per reel, statistical sampling, 100% visual inspection, limits on rework or a particular repair authorization must specify and justify them elsewhere. Do not attribute buyer-created limits to IPC. Conversely, do not conclude that a requirement is unnecessary merely because the public scope says the standard does not define it.

Use a supplement matrix:

On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.

Select class through the project risk process

A workmanship class should be the result of a product decision, not a sales shortcut. The correct decision normally belongs to the customer, product owner, design authority or another party identified by contract. The assembler can explain the manufacturing consequences of the selected class, but it should not silently choose the class from the product description.

Use this sequence:

1. Identify the end use and consequence of failure. Record the operating environment, duty cycle, service access, safety function and consequence of an intermittent or open circuit.
2. Name the decision owner. State who has authority to select the workmanship class and approve deviations.
3. Confirm the exact revision and addenda. Do not rely on a historic drawing note that says only “per A-620.”
4. Map customer drawings and specifications. Identify requirements that are stricter, different or more specific than the workmanship document.
5. Resolve conflicts before quotation. Ask for written clarification where a drawing, bill of materials, terminal supplier instruction or customer specification points in different directions.
6. Freeze the decision in the order package. Put the class, revision, precedence and approved exceptions on the purchase order, controlled drawing or quality plan.
7. Flow the same decision to every production location and approved subcontractor. A class written in an email but absent from the released traveler is not an effective requirement.

The purchasing team should avoid copying a class from another program simply because the products look similar. A harness for a serviceable indoor assembly and one for a safety-related outdoor system may share wire and terminals while having different failure consequences. Conversely, a higher class label does not repair an incomplete drawing, an unqualified application tool or an undefined test plan.

If the team cannot select a class before RFQ, state that the selection is pending and request two clearly bounded quotations or a documented assumption. A supplier should then price the stated assumption without presenting it as customer approval.

Put the class decision in a one-page approval record

A useful approval record can be compact:

On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.

This record does not replace the licensed standard. It prevents the class choice from being separated from the reasons, authorities and controlled product identity behind it.

Convert workmanship into objective evidence

A statement such as “built to IPC/WHMA-A-620” is not yet an acceptance package. The buyer needs evidence that ties the ordered harness, applicable requirement and actual production result together.

Ask the supplier to propose an evidence matrix before award:

On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.

The buyer does not always need every raw record with every shipment. The RFQ should distinguish among submit with quotation, submit for first article, ship with each lot, and retain for audit. This keeps the package proportionate while preserving the right evidence for the risk.

Treat hidden features as a separate evidence decision

Many important termination characteristics are not fully visible after assembly. The public IPC overview explicitly says the standard does not provide cross-section or X-ray acceptance criteria. If a customer requires a crimp microsection, X-ray, destructive pull or another hidden-feature assessment, define the method and acceptance source separately.

For crimp-specific sourcing, the related guides on tooling, pull testing and cross-section evidence and cross-section geometry and void evidence show how to separate measurable process evidence from a general workmanship statement.

The RFQ should identify:

• the feature to be examined;
• the terminal, splice or connection family;
• the method and preparation procedure;
• the acceptance authority, such as a released customer specification or terminal manufacturer requirement;
• the sample timing and quantity;
• the required image or data fields;
• the person authorized to approve an exception;
• record retention and traceability.

Do not write “microsection per A-620” when the actual numerical criteria come from another controlled source. Name that source.

Separate electrical release from visual workmanship

Visual acceptance cannot prove continuity, isolation, dielectric integrity or low-resistance performance. Electrical testing also cannot prove every visual and dimensional feature. Use separate, traceable plans.

The continuity, insulation-resistance and hipot evidence guide explains how to state limits, programs and test records. The end-of-line fixture guide covers fixture identity and false-failure controls. Where low joint resistance is commercially important, the Kelvin resistance testing guide provides a separate decision framework.

In the RFQ, link each evidence item to a release decision. For example, “100% continuity test” should identify the test program revision, product identity, fixture identity, pass/fail result and disposition route. It should not be used as a substitute for workmanship inspection.

Build an inspection-frequency plan instead of citing the standard

The public IPC scope page says the standard does not specify inspection frequency. Therefore, a buyer should not assume that invoking IPC/WHMA-A-620 automatically creates incoming, in-process or final inspection intervals.

Build a frequency plan around product and process risk. At minimum, consider:

• first production after a new release;
• first production after a drawing or bill-of-material change;
• new or transferred tooling;
• applicator maintenance or major adjustment;
• new production location;
• new operator authorization;
• material lot changes where the control plan treats them as significant;
• restart after a prolonged interruption;
• evidence of drift, defect or customer complaint;
• stable routine production after capability is demonstrated.

The plan may combine 100% checks, sampling, setup verification and periodic destructive verification. The correct mix depends on the characteristic, detection method, process capability and consequence of escape. The RFQ should request the supplier's proposed control plan and require customer approval where the buyer owns the sampling decision.

Avoid universal phrases such as “inspect every 100 pieces” unless the number comes from a controlled product requirement or approved risk analysis. An interval copied into every RFQ can create excessive cost for one process and inadequate control for another.

Define what changes the frequency

A mature plan includes escalation and reduction rules. Examples of questions to answer are:

• What event returns a stable process to first-article or heightened inspection?
• How many consecutive conforming lots are needed before a reduced frequency is permitted?
• Who may approve a reduced frequency?
• Does a tooling repair reset the baseline?
• How are suspect units bounded when a check fails?
• Does the supplier inspect only the current unit, or all units since the last accepted verification?
• What records prove that the frequency rule was followed?

The supplier's answer should be auditable. “According to our quality system” is too broad unless the cited procedure and revision are available to the authorized reviewer.

Control defects, process indicators and rework explicitly

The official IPC public overview states that the standard does not set a limit on the number of process indicators or the number of allowable repair or rework actions. This is a critical RFQ gap.

A buyer that cares about repeated rework, cosmetic accumulation or reliability risk should define an additional rule. The rule might require notification after a stated type of rework, prohibit rework on a named feature, require engineering approval for a second repair, or require disclosure of all repairs in the first-article package. The appropriate rule must come from the product authority and risk assessment.

Do not treat the terms defect, process indicator, repair and rework as interchangeable. The licensed standard and customer documents govern their formal use. In the commercial workflow, the important controls are:

1. record the observed condition and affected product identity;
2. identify the exact requirement used for classification;
3. contain potentially affected units;
4. route disposition to the authorized role;
5. perform only an approved repair or rework instruction;
6. repeat required inspection and electrical testing;
7. preserve the original condition, action and final result in the record;
8. assess whether a corrective action or broader lot review is required.

An RFQ can request this workflow without reproducing the copyrighted acceptance text.

Verify the manufacturing site and flowdown

Evidence should identify the actual manufacturing location. A group-level certificate, employee credential or marketing page may not cover the site that will build the order. The quote should name the proposed site and disclose any outsourced operations that affect conformity.

Ask these questions:

• Which legal entity and physical site will assemble the harness?
• Which operations, if any, will be subcontracted?
• Which revision of the governing documents is available at each point of use?
• How are customer-specific requirements flowed to subcontractors?
• Who approves supplier changes?
• Can the supplier show that the quoted site is within the scope of any company-level qualification it claims?
• How are records retrieved when work crosses sites?

IPC's public QML information can help a buyer understand the difference between a named qualified company/location and an individual's training credential. The buyer should verify any claimed listing directly and should not infer that the listing proves acceptance of a particular delivered product.

Use bid gates that produce comparable supplier responses

A two-stage gate is faster than collecting broad quality statements and resolving the gaps after purchase.

Gate 1: quotation completeness

Require each bidder to return:

On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.

A blank answer is not a conformance statement. Treat omissions as open items.

Gate 2: pre-production readiness

Before production release, close:

• approved drawing and bill of materials;
• standard revision, class and supplements;
• approved conflict-resolution record;
• site and subcontractor identity;
• tooling and program revisions;
• first-article scope;
• in-process and final inspection plan;
• electrical test specification;
• hidden-feature verification, if required;
• nonconformance and rework routing;
• record format, retention and delivery;
• change-notification triggers.

The battery cable first-article and change-control guide gives a deeper framework for configuration freezes and reapproval events.

A bounded worked RFQ example

Assume a buyer is sourcing a small harness family with crimped terminals, a branch splice and an end-of-line continuity test. The buyer has not yet approved hidden-feature criteria.

A defensible RFQ package could say:

This example deliberately avoids inventing class selection, sampling quantities, crimp dimensions, pull values or test limits. Those fields must be filled by the responsible authority from controlled evidence before release.

What a weak response looks like

Treat these statements as prompts for clarification:

• “IPC certified factory” without the exact program, site, scope and validity;
• “Class 3 quality” without customer class selection and revision;
• “100% inspection” without named features, method or records;
• “All operators certified” without authorization scope and validity;
• “Full traceability” without defining the unit, lot and record relationships;
• “No defects” without stating the acceptance basis;
• “Standard rework allowed” without limits, instructions or approval authority.

The problem is not that every statement is necessarily false. The problem is that none is specific enough to make a comparable, auditable purchase decision.

Write a complete RFQ clause set

A practical clause set should contain these blocks.

1. Document identity

State the exact standard, revision, class, applicable supplements and language. Require the supplier to flag any obsolete or unavailable reference before quotation.

2. Precedence and exceptions

State the document hierarchy and require clause-level written exceptions. Silence should not change the governing requirement.

3. Configuration

Name the drawing, bill of materials, approved manufacturer list and customer specification revisions.

4. Site and people

Require the proposed manufacturing site, outsourced operations, applicable organization qualification claims and operator authorization system.

5. Process controls

Request tool, applicator, test program and work-instruction identity at the level needed for traceability. Avoid demanding proprietary process detail that does not affect acceptance.

6. Inspection and test

Define visual, dimensional, destructive and electrical evidence separately. Name the acceptance authority and frequency for each.

7. Nonconformance and rework

Define containment, disposition authority, repeat testing, record requirements and notification triggers.

8. Record delivery and retention

State what comes with the quote, first article and each shipment, what may remain at the supplier, the retention period and retrieval time.

9. Change control

List changes requiring notice or approval. Include revision, material, approved source, tooling, process, software, test fixture, site and subcontractor changes as applicable to the product.

10. Commercial response

Ask the supplier to identify cost, lead-time and minimum-order assumptions separately. Do not infer those commercial terms from workmanship compliance.

When the technical package is ready, use the SINAWATTS product catalog to identify the relevant component family. In the Send an IPC/WHMA-A-620 evidence RFQ, include the drawing revision, selected class, governing revision, site restrictions, evidence matrix and requested delivery stage. SINAWATTS should confirm only capabilities and terms supported by the specific quotation and released order package.

Buyer checklist before award

Use this final check:

• [ ] Exact IPC/WHMA-A-620 revision is stated.
• [ ] The class was selected by the authorized customer or design role.
• [ ] Applicable supplements are named.
• [ ] Requirement precedence is explicit.
• [ ] Drawing and bill-of-material revisions are frozen.
• [ ] The manufacturing site and outsourced operations are disclosed.
• [ ] Individual credentials and organization/site qualifications are not conflated.
• [ ] Inspection frequency is defined outside the generic standard citation.
• [ ] Hidden-feature methods and numerical criteria have a named authority.
• [ ] Electrical release has its own limits, program identity and records.
• [ ] Process-indicator and rework limits are explicit where the product needs them.
• [ ] First-article, lot and retained records are separated.
• [ ] Deviations require written approval.
• [ ] Change triggers and reapproval rules are defined.
• [ ] Commercial assumptions are listed separately from quality claims.

If any box remains open, record it as a controlled RFQ assumption. Do not let an incomplete sentence become an implied product requirement.

Evidence boundaries

This guide uses public IPC pages and public manufacturer-neutral procurement logic. It does not reproduce IPC/WHMA-A-620 acceptance criteria, define the formal characteristics of a workmanship class or replace access to the licensed document. It also does not determine the correct class, inspection frequency, sample size, crimp dimensions, electrical limits or rework allowance for a specific harness.

IPC public information can establish document identity, broad scope, certification program categories and stated exclusions. It cannot prove that a supplier, location, employee or shipment meets the buyer's requirement. Verify any claim against the current official listing, certificate scope, quotation and product records. Customer drawings, product safety analysis, terminal manufacturer instructions and applicable law may add requirements.

SINAWATTS capabilities, qualifications, test resources, materials, price, MOQ and lead time must be confirmed in a product-specific quotation. Nothing in this article should be read as a claim that a particular capability or certification is available.

Buyer FAQ

Does “built to IPC/WHMA-A-620” identify an acceptable harness?

No. It is incomplete unless the order also identifies the revision, customer-selected class, applicable supplements, precedence, drawings, exceptions, inspection plan and required evidence. The statement describes an intended reference but does not prove product acceptance.

Which IPC/WHMA-A-620 revision should an RFQ use in October 2026?

IPC's public document revision table lists IPC/WHMA-A-620 Revision F with an October 2025 issue date. A buyer should verify the table on the day of release and then state the exact approved revision. Do not silently change an existing controlled program from an older revision; use formal impact review and approval.

Can a supplier choose the workmanship class?

Only if the contract gives it that authority. Normally the customer, design authority or product owner selects the class through the product risk process. A supplier may explain manufacturing implications or quote a documented assumption, but the assumption is not customer approval.

Does an IPC individual certification prove that a factory is qualified?

No. An individual credential, an organization or location qualification and acceptance of a specific shipment are different claims. Verify the exact certification program, person or site, scope, validity and relationship to the ordered product.

Does IPC/WHMA-A-620 define how often every feature must be inspected?

The public IPC overview says the standard does not specify inspection frequency. The buyer and supplier need an approved control plan based on product and process risk, with escalation and change rules.

Does IPC/WHMA-A-620 contain cross-section or X-ray acceptance criteria?

IPC's public overview states that it does not provide cross-section or X-ray criteria. If those methods are required, identify the separate controlled acceptance source, method, sample plan and record format.

Is 100% continuity testing enough for acceptance?

No. Continuity testing addresses an electrical condition, not all visual, material, dimensional or hidden termination characteristics. Use separate workmanship, dimensional and electrical evidence tied to the same configuration.

Is a higher workmanship class automatically better for every product?

No. The class must match the authorized product decision and contractual requirements. A higher label cannot compensate for an incomplete drawing, uncontrolled tooling, missing test limits or poor traceability, and it may add cost without addressing the actual risk.

How should conflicts between a drawing and the workmanship standard be handled?

Define precedence in the RFQ and route the specific conflict to the authorized customer role before production. Record the written resolution against the affected drawing note or requirement. Do not rely on an operator or buyer to resolve it informally on the shop floor.

Can the RFQ allow repair or rework without limits?

It can, but that may create an uncontrolled risk. The public IPC overview says the standard does not set a numerical limit on repair/rework actions. If the product needs limits or notification, define them in the customer specification or approved quality plan.

What records should travel with every lot?

That depends on product risk and contract. Common candidates are configuration identity, quantity, final release, required electrical results, material or lot traceability and approved nonconformance references. Keep larger raw inspection datasets available for audit if the contract does not require shipment copies.

What should trigger a new first article?

Define triggers contractually. Common candidates include drawing, bill-of-material, terminal, wire, approved source, tooling, process, test program, fixture, production site or subcontractor changes, plus restart after defined interruptions or significant nonconformance. The buyer should approve the final trigger list.

What should a buyer send for an efficient quotation?

Send controlled drawings and BOMs, the exact revision/class/supplements, precedence rules, evidence matrix, test requirements, site restrictions, record-retention needs, required delivery date and commercial quantities. Mark every unresolved field as an assumption or question.

Official sources checked on 2026-10-08

1. IPC Document Revision Table — public document identity and revision/date listing for IPC/WHMA-A-620.
2. IPC Meet Your Standards: IPC/WHMA-A-620 — public scope and stated exclusions, including inspection frequency, cross-section/X-ray criteria, process-indicator limits and repair/rework limits.
3. IPC/WHMA-A-620F public table of contents — section structure and evidence-planning context; acceptance text is not reproduced here.
4. IPC Certifications — official overview of IPC certification programs and roles.
5. IPC Validation Services: IPC/WHMA-A-620 QML — official information on organization/location qualification and public listing context.

Source pages can change. Recheck document identity, program scope and public listings when the RFQ is released.