This comprehensive audit checklist is designed for procurement engineers, quality managers, and supplier development teams. It covers three main audit areas for a fastener manufacturing facility serving automotive and general manufacturing industries: (1) Quality Management System audits (ISO 9001, IATF 16949), (2) Technical Capability audits (manufacturing processes like forging, cold heading, heat treatment, plating, thread rolling), and (3) Supplier Qualification audits. Each section lists key inspection points to ensure process control, traceability, certifications, defect prevention, inspection/testing, calibration, and proper packaging/logistics.

1. Quality Management System (QMS) Audit Checklist

• Certification & Standards: Verify the company holds current ISO 9001:2015 certification and, for automotive supply, IATF 16949:2016 certification. Ensure all applicable standards (e.g. ASTM, DIN) and customer-specific requirements (PPAP, special process specs) are documented and met by procedures.
• Quality Policy & Objectives: Check that a quality policy exists and is communicated to all staff. Confirm measurable quality objectives and performance targets are defined, monitored, and reviewed (e.g. defect rates, on-time delivery, customer complaints).
• Management Review: Ensure regular management review meetings are held (at least annually) with documented minutes. Reviews should cover key metrics (quality performance, audit results, corrective actions, process performance) and decisions for improvement.
• Document & Record Control: Confirm all procedures, work instructions, control plans, and FMEAs are approved, current, and readily available at the point of use. Verify obsolete documents are removed or marked. Ensure records of production, inspection, and testing (e.g. dimensional reports, test certificates) are maintained with proper retention.
• Internal Audits & CAPA: Verify an internal audit program is in place and covers all critical processes and QMS elements. Check that any audit findings have been addressed with corrective/preventive actions (root-cause analysis, fixes) and that effectiveness of corrections is reviewed.
• Training & Competency: Review training records and matrices to confirm employees (operators, inspectors, maintenance) are trained for their tasks. Check competency assessments for critical roles (machine setup, quality inspection, safety) and that ongoing training or cross-training exists.
• Process Control & Planning: Inspect control plans and FMEAs for each fastener family. Verify key process parameters and quality characteristics are defined. Check that first-article inspections are performed and that in-process inspections or SPC are conducted per plan.
• Measurement, Analysis & Equipment: Ensure all measuring instruments and test equipment (calipers, micrometers, hardness testers, tensile testers, torque testers) are calibrated on schedule and traceable to standards. Confirm calibration records and certificate validity. Verify that test methods (e.g. tensile test, torque/angle tests for bolts) are defined, validated, and followed.
• Control of Nonconformance: Check procedures for identifying and segregating nonconforming parts. Verify that nonconforming fasteners are clearly marked and controlled (scrapped, reworked, or concessioned). Confirm that nonconformance reports are issued, root causes are analyzed, and corrective actions are implemented and tracked.
• Traceability: Ensure that each batch or lot of fasteners is fully traceable through manufacturing. Verify that raw material heat numbers are recorded on production travelers or batch tags, linking incoming material certificates to finished parts. Confirm that traceability records are retained for the required period.
• Customer & Regulatory Requirements: Verify that customer-specific requirements (e.g. PPAP documentation, special packaging, marking, testing) are identified and incorporated into procedures. Check that any regulatory requirements (environmental, safety) relevant to fasteners are recognized (e.g. RoHS, REACH for coatings) and complied with.
• Packaging & Logistics: Ensure packaging procedures meet customer and industry requirements. Check that packaging materials (boxes, bags, desiccants, corner boards) protect fasteners from damage and corrosion. Verify that labels include part number, batch, quantity, and that packaging is labeled per customer spec. Confirm that shipping and delivery processes are defined (packing lists, certificates accompany shipments) and that on-time delivery performance is monitored.
• Continuous Improvement: Look for evidence of continuous improvement initiatives (e.g. Kaizen, Six Sigma projects) aimed at reducing defects or improving efficiency. Check that production metrics are analyzed (scrap trends, process capability) and that improvement actions are logged and followed through.

2. Technical Capability Audit Checklist

Forging

• Material Verification: Confirm raw forging stock (bars, ingots, billets) has correct material grades and heat numbers. Check that mill test reports are on file and incoming chemical/physical tests (positive material ID, hardness) are performed as per control plan.
• Process Parameters: Verify forging presses/furnaces are set to the correct temperature and pressure. Check that forging reduction ratios and sequence (number of blows or presses) follow approved process documentation. Ensure forging dies are the right design for the part.
• Equipment & Maintenance: Inspect forging equipment (presses, induction heaters, furnaces) for good condition and proper maintenance. Verify that preventivemaintenance is scheduled (hydraulic systems, electric components) to avoid unexpected stops.
• In-Process Inspection: Ensure forged parts are inspected during production. Check for defects like cracks, laps, or folds on each forged piece. Verify dimensional checks on first articles and samples (length, diameter, cross-section) and that any out-of-tolerance is addressed immediately.
• Heat Treatment Coordination: If heat treatment is done in-house or outsourced, confirm that forged batches are promptly heat treated to specification. Check that post-forging annealing or normalization steps (if required) are performed and documented before further processing.
• Traceability: Confirm each forging batch is tagged or labeled so it can be traced back to the raw material heat and process records. Verify tracking between forging and downstream processes (e.g. heat treat lot numbers).
• Quality Records: Review forging process records (temperature logs, reduction logs) and mechanical tests (hardness or tensile samples) to ensure consistency with requirements.

Cold Heading

• Machine Setup & Tooling: Verify correct dies and punches are installed for each fastener design. Check that blank feeding (bar stock diameter, cut-off length) is consistent and that stock is deburred and straight before feeding.
• Process Parameters: Ensure cold heading presses are set to proper stroke length, feed rates, and lubrication is adequate. Verify that lubricant type and quantity are correct and logs of lubricant replacement are maintained.
• Die & Tool Maintenance: Inspect dies and punch tooling for wear or chipping. Check that a schedule exists for replacing or refurbishing heading tools to maintain dimensional accuracy.
• In-Process Quality Checks: Confirm first-piece parts are inspected for head dimensions (height, diameter) and that periodic sampling during runs checks critical features. Check that split heads or burrs are recorded and trigger corrective action.
• Burr and Defect Control: Ensure any flash or burr created by heading is removed (e.g., stamping or grinding). Verify operators log defects and that these logs feed into process improvement.
• Post-Heading Operations: If threading or other operations immediately follow heading, verify that process changeovers are controlled to ensure correct sequence. Check that parts are cleaned (deburred) before thread rolling or plating.

Heat Treatment

• Equipment & Settings: Check that furnaces (salt bath, pit, continuous) are calibrated and controlled. Verify set temperatures and times match material specifications. Confirm thermocouple calibration and that temperature uniformity across loads is maintained.
• Process Control: Review heat treat process sheets. Ensure that parts are correctly loaded (e.g. hooks for immersion quenching) and cycle parameters (temperature ramp, hold time) are followed. Check quenching method (oil, water) and that agitation or quench speed is as required.
• Quench Medium Maintenance: Inspect quench baths for correct concentration, contamination, and agitation. Check records of oil/water quality (e.g. hardness of water, bath additive levels) if applicable.
• Hardness & Material Testing: Confirm hardness test equipment (Rockwell, Brinell) and tensile testers are calibrated. Verify samples from each heat treat batch are tested for hardness and meet the specification. Check if decarburization or grain structure is inspected for sensitive applications.
• Subcontractor Oversight: If heat treating is outsourced, ensure the vendor is qualified (ISO/NADCAP) and that heat treat certificates/test reports accompany returned parts. Inspect incoming plated parts for correct hardness and microstructure.
• Traceability of Loads: Ensure each heat treat load or batch can be traced to specific part lots (via tags or production orders). Verify that load records (temperature profiles, times) are archived.

Plating / Coating

• Process Setup: Verify the type of plating/coating matches engineering requirements (e.g. zinc dichromate, yellow or clear, black oxide). Check that plating lines have the correct process parameters and that the tanks are labeled with current bath chemistry.
• Bath Monitoring: Ensure plating baths are sampled and tested regularly (acid/alkalinity levels, metal content). Confirm filters and recirculation systems are working. Check logs for bath maintenance (additives, filters replaced).
• Thickness & Quality Checks: Confirm that plating thickness is measured on samples using XRF or other gauge and meets specifications. Inspect plated parts for uniform coverage, no flaking or dull spots. For cadmium or zinc plating, ensure chromate coating is proper.
• Salt Spray/Corrosion Testing: If required by customer, verify salt spray test results or other corrosion test records meet requirements. Check that test methods (ASTM B117, etc.) are followed and recorded.
• Environmental & Safety Controls: Verify that chemical handling (e.g. lead, cadmium, cyanide plating) follows safety protocols. Check ventilation, PPE, and disposal procedures comply with regulations. Ensure Material Safety Data Sheets (MSDS) are available.
• Passivation & Sealing: Ensure any required post-treatments (e.g. oil dip, clear coating, passivation) are applied correctly. Check that drying ovens or blow-off stations are operating and that parts are free from moisture before packaging.
• Subcontracted Plating: If using outside platers, confirm they are audited/approved. Ensure plating certificates (thickness, adhesion tests) are provided and material is quarantined until verified.

Thread Rolling / Machining

• Machine Setup: Verify thread rolling dies or tapping fixtures match the fastener design. Check press or machine settings (speed, force) are per process instructions.
• Lubrication & Cleanliness: Ensure proper use of thread rolling oil or cutting fluid. Check that parts are cleaned (e.g. pickled or rinsed) so threads are free of debris before rolling.
• Inspection Gauges: Confirm calibrated GO/NO-GO thread gauges are available for each thread size. Check that operators use these gauges on first-piece and periodic samples. Ensure worn gauges are replaced.
• Thread Quality Checks: Inspect threads with optical comparator or CMM for profile, pitch diameter, and thread form. Check for defects like flattened crests or pitch errors. Verify nuts/bolts assemble with matching counterparts.
• Defect Management: Ensure any rolled threads with splits or burrs are reworked correctly (e.g. re-roll authorized parts, re-tap if necessary) and re-inspected. Check logs of thread defects and any corrective action.

3. Supplier Qualification Audit Checklist

• Approved Supplier Program: Verify that raw material suppliers (steel mills, wire/rod vendors) and service suppliers (heat treat, plating, testing labs) are selected based on documented criteria. Check that each supplier is on an approved vendor list and that supplier assessments or audits have been performed.
• Supplier Certifications: Confirm that key suppliers hold necessary certifications. For automotive, raw material mills and subcontractors should be ISO 9001/IATF 16949 certified if required. Specialty subcontractors (NDT labs, plating houses) should have relevant standards (e.g. ISO/IEC 17025 for labs, NADCAP for aerospace plating).
• Incoming Material Inspection: Check that incoming raw materials (steel bars, wire, blanks) are inspected against purchase orders. Verify material certificates (heat/cast analyses) are validated against specifications. Ensure traceability from incoming batch to production.
• Subcontractor Controls: Review oversight of subcontracted processes. Ensure that heat treatment and plating vendors follow approved processes. Check that vendor process certifications (e.g. furnace calibration, plating thickness certificates) are received and meet requirements.
• Supplier Change Notification: Ensure there is a documented process requiring suppliers to notify of any changes in material grade, production processes, or subcontractors. Verify that any changes have been approved internally before acceptance.
• Supplier Performance Monitoring: Confirm that the manufacturer tracks supplier performance metrics (on-time delivery, PPM defects, nonconformance incidents). Check records for supplier scorecards or reviews and that poor performance prompts corrective action or sourcing changes.
• Packaging Suppliers: Verify that packaging materials (boxes, foam, desiccants) are obtained from qualified vendors. Check that packaging meets specifications (strength, labeling) and that packaging suppliers are evaluated for quality if they affect product integrity.
• Logistics & Delivery: Check that shipping/logistics providers (if outsourced) meet delivery requirements. Verify shipping documentation (packing lists, certificates of conformity, MSDS for hazardous materials if any) are complete and accurate. Ensure tracking and insurance measures protect the product in transit.
• Contingency Planning: Evaluate whether contingency plans exist for critical suppliers (alternate sources identified). Check that risk assessments cover supply chain disruptions (material shortages, single-source dependencies) and that business continuity plans are in place.

This structured checklist ensures the fastener manufacturer’s processes, quality systems, and supply chain are thoroughly audited. It covers process control, traceability, certifications, defect handling, dimensional inspection, testing methods, strength/torque validation, calibration, packaging, and logistics to meet automotive and general manufacturing standards.