ISO 9001 Certified: Quality Control and Inspection for Precision Custom Parts
Since 1993, Prime has run an ISO 9001–based quality system to control every step, from raw material spectrometer checks to final CMM inspection across 10+ production lines for CNC, casting, stamping and fasteners.
ISO 9001 Certified Quality Management
100% Inspection for Critical Dimensions
Incoming, In-Process & Final Quality Checks
Detailed Quality Reports for Every Order
Our Commitment: Zero-Defect Delivery and Full Traceability
We understand that quality is non-negotiable in precision parts sourcing. As an ISO 9001:2015 Certified manufacturer, we implement a stringent Quality Management System (QMS) that surpasses industry standards. This ensures every step, from initial design review to final shipment, is controlled, documented, and fully traceable.
Our Core Traceability Promise: All critical raw materials are supplied with MTRs (Material Test Reports) and COCs (Certificates of Conformance), eliminating supply chain risk for your most demanding projects.
Traceability
Every batch of materials, every process, and every batch of inspection records is numbered and archived for easy traceability.
Prevention First
Reduce defects at the source through DFM, process planning, fixtures and jigs, rather than relying on post-selection.
Measurable
Manage quality using data such as SPC (Statistical Process Control), sampling records, and pass rates, rather than relying on intuition.
Transparent
We can provide customers with documents such as material certificates, inspection reports, and production records to facilitate review and internal archiving.
End-to-end quality control from inquiry to shipment
We don’t just “pick and choose” before shipping; instead, we control risks at every stage, from the early stages of the project, incoming materials, production process to final packaging, making it easier for you to pass internal approvals and customer reviews.

Preliminary review and project initiation
Review drawings and technical requirements to confirm material grades, critical dimensions, surface finishes, and testing standards; conduct DFM reviews and, if necessary, recommend optimizations to chamfers, fillets, thicknesses, or hole spacing; confirm sample plans and quality control plans with the customer.

Incoming Quality Control (IQC)
Check the specifications, furnace numbers, and supplier certificates of raw materials. If necessary, re-analyze the chemical composition using a spectrometer. Perform dimensional and appearance spot checks on standard parts and purchased parts.

Process Quality Control (IPQC)
Conduct first article inspection (FAI) using calipers, micrometers, projectors, or coordinate measuring machines to measure critical dimensions; conduct routine inspections by time or quantity, and coordinate with mold wear and tool life management to maintain batch stability.

Final inspection and shipment (FQC / OQC)
Inspect dimensions, appearance, threads, and mating surfaces according to the control plan; verify packaging, labels, and quantities before shipment, generate a final inspection report or certificate of conformity, and send it with the goods or by mail.
Quality testing equipment
From incoming materials to shipment, we use three main categories of testing equipment—size, material, and specialized inspection tools—to ensure that every batch of customized parts is within a controllable range.
Dimension and shape inspection equipment
To ensure critical dimensions and geometric tolerances, we have equipped our quality laboratory and production site with a variety of dimensional inspection equipment:
- * Coordinate Measuring Machine (CMM): Used for precision inspection of complex three-dimensional geometries and critical mating surfaces.
- * Optical projector: Used for features that are difficult to measure directly, such as contours, chamfers, and tiny holes.
- * Digital calipers and micrometers: used for everyday length, diameter, and thickness measurements.
- * Height gauge and granite platform: used for height, step, and verticality measurement.
- * Thread go/no-go gauge: Used for checking the accuracy and fit of internal and external threads.
Material and performance testing equipment
For parts with high requirements for load-bearing capacity, wear resistance, and high temperature resistance, we will conduct material and performance testing according to project needs:
- * Spectrometer: Used to check whether the chemical composition of randomly selected metallic materials conforms to the specified grade.
- * Hardness tester (Rockwell/Britt): Confirms the hardness range after heat treatment
- * Tensile testing machine (if required by the project): Tests yield strength and tensile strength
- * Coating thickness gauge: Detects the coating thickness of surface treatments such as zinc plating and nickel plating
- * Salt spray test chamber (suitable for corrosion protection projects): Assesses corrosion resistance and service life trends
Specialized measuring tools and inspection fixtures for custom parts
For custom-made parts with special structures and strict fitting requirements, we will design and manufacture special measuring tools and inspection tools according to project needs:
- * Go/No-Go Gauges and Special Inspection Tools: Used for rapid determination of functional dimensions such as special slots, positioning holes, and insert/pull-in fits.
- * Air Gauges / Hole Gauges (if applicable): Used for high-precision internal hole dimension and roundness inspection.
- * Specialized Measuring Tools for Shafts and Cylindrical Units: Used for roundness, coaxiality, and runout control.
These specialized measuring tools allow us to quickly determine on the production floor whether parts meet assembly and functional requirements, rather than relying solely on laboratory measurements.
What quality reports can we provide?
To facilitate your internal approvals, PPAP submissions, and client reviews, Prime can provide corresponding quality documents and reports for different projects.
By default, each order can provide:
Basic Dimension Inspection Report (Spot Inspection or Full Inspection Record of Critical Dimensions)
Appearance and surface inspection records
Certificate of Conformity / Declaration of Conformity (COC / COA)
Packing list and carton label with batch information
Optional services available upon request:
* Material Testing Certificate (MTC) or Steel Mill Certificate
* Full-Dimensional Coordinate Measuring Machine (CMM) Inspection Report
* Hardness Report / Heat Treatment Certificate
* Surface Roughness Inspection Report
* Coating Thickness and Salt Spray Test Report
* PPAP Documents for Automotive Projects (e.g., Control Plan, Flowcharts, etc.)
* First Article Inspection Report (FAI)
* RoHS / REACH and other Environmental Compliance Declarations (as required by the project)
Significance for the procurement and engineering teams:
* Easier to pass end-customer supplier audits and annual assessments
* Facilitates the organization of APQP/PPAP/project files
* In case of problems, quick traceability to material batches, production batches, and testing records is possible.
Quality control for different industries
Different application scenarios have completely different quality concerns. Prime will customize corresponding inspection items and documentation support according to the standards of specific industries such as automotive, electrical, construction, and high-temperature conditions, making your internal audits and end-customer audits smoother.
Automotive and Industrial Equipment
We strictly control critical dimensional tolerances, fatigue life, and batch consistency. We can provide a complete set of PPAP documents, control plans, and sample retention management according to automotive-grade project requirements, helping you pass the rigorous audits of OEMs and Tier 1 suppliers.
Electrical and power distribution fields
The key verification focuses on insulation performance, temperature resistance rating, and terminal hole accuracy. It supports the provision of reports such as material certification and flame retardant rating tests, and can comply with relevant standard requirements to ensure the long-term safe operation of distribution cabinets, switches, and wiring terminals.
Building and fastening systems
We focus on rust prevention, loosening prevention, and installation torque performance. We assess protective capabilities through coating thickness testing and salt spray testing, and combine batch and label management to ensure that every batch of bolts, nuts, and connectors is traceable and verifiable.
Cement, Mining and High-Temperature Working Conditions
For high-wear, high-temperature and impact conditions, we focus on evaluating wear resistance, thermal crack resistance and dimensional stability. Through chemical composition control, hardness testing and on-site feedback, we continuously optimize material formulation and heat treatment schemes to extend the life of key components.
Quality Control Cases
Through real-world project case studies, we demonstrate how Prime helps overseas clients solve problems such as dimensional fluctuations, high-temperature failures, and precision tolerances through quantifiable quality control.
Stamping bracket project for a US automotive customer
Background:The original supplier's bracket dimensions fluctuated greatly, causing frequent assembly interference and severe on-site rework.
Prime's approach:The control plan was revised, a full-size report was generated for the first piece using CMM, and standards were set for mold maintenance and mold life.
Result:The defect rate dropped below 0.2%, multiple batches were delivered on time, and customer complaints were reduced to zero.
Cement plant heat-resistant casting project
Background:Premature cracking of castings under high-temperature conditions leads to frequent shutdowns for maintenance.
Prime's approach:Strengthen the re-examination of material spectra, increase hardness and (if required by the project) metallographic examination, and establish tracking records for each batch of castings.
Result:The on-site lifespan has been significantly extended, and the number of unplanned downtimes has been greatly reduced.
Precision CNC parts for electrical equipment
background:The customer required a tolerance of ±0.01mm and strict surface roughness, and was initially skeptical of the supplier.
Prime's approach:Design dedicated fixtures, use CMM for full inspection of critical dimensions, and apply SPC monitoring in mass production.
Result:The first batch of samples passed customer verification on the first try, and subsequent batches were supplied stably.
Common Quality Control Issues
Do you provide inspection reports for every batch of goods?
Yes, we can provide relevant inspection documents with the goods, depending on the product type and customer requirements. Common documents include:
1.Dimensional inspection report (including key dimension records, and CMM report if necessary)
2.Appearance and functional inspection records
3.Material certificates / Heat number traceability (MTC)
4.Performance test records for hardness, torque, tensile strength, etc. (if required by the project)
For newly developed parts, small-batch trial production, and engineering change batches, we will by default retain complete first-article and process inspection records for customer traceability. For regular mass production batches, if the customer has a fixed template, we can also issue reports according to the customer’s template.
What sampling standards (e.g., AQL) do you typically use?
For final inspection before shipment, we usually follow the ISO 2859-1 sampling standard and set the AQL value based on the project’s risk level. For example:
1.Critical dimensions/critical functions: AQL 0.65 or 1.0
2.General dimensions: AQL 1.0 or 2.5
3.Minor appearance defects: AQL 2.5 or 4.0
If you have your own AQL and classification requirements (Critical/Major/Minor), please provide them in advance. We will solidify them in the control plan and inspection instructions and strictly adhere to your standards.
What do you do when you find non-conforming products?
When you find non-conforming products, we will handle them according to the following steps:
1.Immediate Isolation: Isolate the non-conforming products from the good products, affix clear labels, and prevent them from flowing into the next process or being shipped.
2.Root Cause Analysis: The engineering and quality teams will conduct 5 Whys, fishbone diagrams, and other analyses to identify the root cause.
3.Handling Measures: Depending on the situation, we will choose rework, redo, or scrap. All reworked parts must be 100% re-inspected.
4.Preventive Measures: Optimize tooling, process parameters, inspection frequency, etc., and update the FMEA and control plan if necessary.
5.Records and Feedback: Complete records will be kept in the NCR/8D report, and written explanations will be provided when required by the customer.
For batches already delivered, if there is indeed a risk, we will proactively communicate with the customer to assess the risk and negotiate a recall or on-site screening solution.
Can we specify our own critical dimensions and inspection frequency?
Yes, and we strongly encourage this. You can mark the critical dimensions (CTQ/SC) on the drawings, or list them in an Excel spreadsheet/table:
1.Critical Dimension / Tolerance Requirements
2.Inspection Methods and Gauges (e.g., calipers, micrometers, CMM, etc.)
3.Inspection Ratio and Frequency (First Article Inspection, Patrol Inspection, Final Inspection, etc.)
We will update our internal control plan and inspection instructions according to your requirements, and strictly adhere to the agreement during the first article and mass production stages. If necessary, we can provide you with sample inspection records for confirmation.
Can you support on-site inspections by third-party organizations (such as SGS, BV)?
Yes, we can. We can:
1.Cooperate with your designated third-party organizations such as SGS, BV, and TÜV to conduct on-site inspections or checks;
2.Prepare samples, documents, and site conditions in advance, and cooperate item by item according to the third-party inspection checklist;
3.If necessary, we can also assist in contacting local third-party organizations and scheduling inspection services on your behalf (the cost-sharing method will be confirmed by the customer).
All third-party reports will be kept in our internal records to ensure consistent standards for future orders.
Can you audit your factory and quality system?
We fully welcome client audits. We can cooperate:
1.Online remote audit (video conferencing + on-site wiring demonstration + document sharing)
2.On-site audit at the factory (system audit + on-site processes + warehousing & packaging)
3.Process audits and product audits are conducted for specific projects.
We are ISO certified and have comprehensive process documents, records, equipment ledgers, and training records available for auditing. Following the audit, if you provide suggestions for improvement, we will develop a rectification plan and provide feedback according to the established milestones.
How can we ensure consistent quality in repeat orders?
We ensure consistency in duplicate orders through the following methods:
1.Establish fixed process routes and tooling fixtures for each part to avoid arbitrary process changes;
2.Before production, conduct First Article Inspection (FAI) based on samples or approved first articles;
3.Key parameters (such as mold clearance, machine settings, tool numbers, etc.) are locked in the work instructions;
4.Raw materials are managed by furnace number and batch, with corresponding MTCs issued and recorded in the shipment batch number;
5.Sample parts and inspection records are retained for each batch, allowing subsequent orders to be compared with the retained samples.
If clients have long-term projects, we can also work together to establish mechanisms such as annual review and annual PPAP update.
What quality documents can you provide, such as PPAP, material certifications, and environmental reports?
Based on project requirements, we can provide:
1.PPAP documents (if applicable): including flowcharts, PFMEA, control plans, measurement system analysis, full-size reports, material and performance test reports, etc.
2.Material certification documents (MTC): issued by the steel mill or material supplier, containing chemical composition and mechanical properties;
3.Environmental documents: such as RoHS and REACH declarations, and third-party testing can be provided if necessary;
4.Other industry-specific reports, such as salt spray test reports, coating thickness reports, hardness and torque test records, etc.
If you have a fixed format or a customer-specified template, we can also prepare documents according to the template.
How do you calibrate and maintain your testing equipment?
Our testing equipment undergoes a regular calibration and inspection system:
1.Measuring tools and testing equipment are assigned unique serial numbers and calibration labels, with the next expiration date recorded;
2.Critical equipment (such as CMMs, hardness testers, torque wrenches, etc.) is regularly calibrated by a qualified third-party organization;
3.Commonly used measuring tools in the workshop (calipers, micrometers, plug gauges, etc.) undergo periodic self-inspections and random checks, and are immediately taken out of service if any abnormalities are found;
4.All calibration reports and inspection records are archived and can be reviewed by clients during audits.
This ensures the reliability and traceability of all inspection data.
If we discover quality issues on-site, what is your response mechanism?
If you discover any quality issues on-site, please contact us directly via email, phone, or instant messaging. We will:
1.Reply within 24 hours, confirm the issue, and provide initial handling suggestions;
2.If necessary, we will arrange a video conference to review the on-site situation and problematic samples with you;
3.For urgent issues affecting production, we will prioritize replenishment, rework, or solution selection to minimize the risk of line downtime;
4.Simultaneously, our engineering and quality teams will issue an 8D or similar format corrective and preventative action report, which will be implemented and its effectiveness tracked after mutual confirmation.
Our goal is: rapid response, clear accountability, and actionable solutions, rather than simply passing the problem back to the customer.
Get in touch
Custom Hardware Parts Made Easy
At Prime, we simplify the process of sourcing high-quality, customized hardware parts for your business. Follow these three simple steps to get started:
Tell Us Your Requirements
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Approve for Production
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Get a Free Quote
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