Critical Characteristics
Identify datums, fits, bores, sealing faces, wall sections, material conditions and other characteristics that can affect assembly, sealing, load or service life.
Quality Control & Inspection
Quality Control & Inspection for Cast, Forged and CNC Machined Components
Quality planning starts with the drawing and the finished-part requirement—not with a generic final check. Tianhui defines critical characteristics, verification methods and required records around the selected casting, forging or CNC machining route before production begins.
02 / Quality Planning
Define Critical Characteristics, Verification Methods and Acceptance Criteria Before Production
A useful quality plan answers three questions before production: what is critical, how it will be verified, and what records are required for approval and release.
Verification Method
Match each critical requirement to an appropriate method such as CMM, gauges, roughness testing, hardness, material analysis, NDT or functional testing.
Control Point
Place checks where they can prevent defects or dimensional drift from moving into expensive machining, heat treatment, finishing, assembly or shipment.
Documentation & Release
Agree which material, dimensional, functional, FAI, PPAP or customer-specific records are required for sample approval and production release.
03 / Integrated Inspection Workflow
Use Quality Gates Where Risk Enters the Manufacturing Route
Inspection is most effective when it is placed before a risk becomes expensive to correct. The control sequence therefore changes with casting, forging, machining and secondary operations.
Drawing & CTQ Review
Identify material, tolerances, datums, sealing or load-bearing interfaces, special characteristics and required records.
Material / Blank Verification
Confirm material identity, incoming condition or blank status before value is added through machining or secondary operations.
Process Control Gate
Check selected characteristics at the casting, forging, heat-treatment, machining or finishing stage where risk is best controlled.
Final Dimensional Verification
Verify finished datums, bores, fits, threads, profiles and other drawing-defined characteristics with suitable equipment.
Surface / Mechanical / Functional Tests
Apply agreed roughness, hardness, tensile, metallographic, NDT, pressure/leak, balance, torque or other project-specific checks where required.
Record Review & Release
Confirm the agreed inspection results, certificates and approval records before sample release, batch release or shipment.
04 / Inspection Capability
Match the Verification Method to the Requirement
The same instrument should not be used simply because it is available. The drawing requirement and process risk determine whether the part needs dimensional, material, surface, mechanical, NDT or functional verification.
Material Analysis
Used to verify alloy chemistry and evaluate metallographic condition when the material standard or control plan requires verification.
- Optical Emission Spectrometer
- Metallographic Microscope / Analyzer
Dimensional Inspection
Used for datums, positions, bores, profiles, heights, runout and other drawing-defined characteristics according to tolerance and geometry.
- CMM
- Vision Measuring Machine
- Calipers, Micrometers & Gauges
Mechanical Testing
Used where hardness, tensile performance or heat-treatment condition must be verified against material or project requirements.
- Universal Tensile Testing Machine
- Hardness Tester
Surface & Coating Checks
Used for machined surface roughness, coating thickness and corrosion-related verification when these characteristics are specified.
- Surface Roughness Meter
- Coating Thickness Gauge
- Salt Spray Test Equipment
Non-Destructive Testing
Magnetic particle inspection supports surface and near-surface discontinuity detection on suitable ferromagnetic components.
- Magnetic Particle Inspection
- Other NDT methods should be confirmed during RFQ review when specified.
Functional Verification
Used where the finished component requires sealing, pressure, rotational, balance or torque verification beyond dimensional inspection.
- Pressure / Leak / Air-Tightness Testing
- Dynamic Balancing
- Torque Testing
05 / Inspection Equipment
Inspection Equipment for Dimensional, Material and Functional Verification.
Production and inspection images show the equipment used to support dimensional, material, surface and functional verification.
06 / Quality Documentation
Agree the Quality Records Before Production Starts
Not every order needs every report. The documentation scope should match the drawing, application risk and customer approval requirements before quotation or sample production.
| Document / Record | Typical Use | Availability |
|---|---|---|
| Material Certificate | Confirm specified material or heat information. | When specified |
| Chemical Composition Report | Verify alloy chemistry where required. | Project-specific |
| Dimensional Inspection Report | Record agreed drawing characteristics or critical dimensions. | Available by scope |
| Hardness / Mechanical Test Record | Support heat-treatment or mechanical-property requirements. | When applicable |
| Surface / Roughness Record | Verify specified machined or finished surface requirements. | When applicable |
| Pressure / Leak Test Report | Document pressure, leakage or air-tightness checks for fluid-handling or sealed components. | When specified |
| NDT Report | Document the agreed non-destructive examination method and acceptance result. | Project-specific |
| Dynamic Balance / Torque Record | Document functional checks for applicable rotating or assembled parts. | When applicable |
| FAI / First Article Record | Support initial sample approval before repeat production. | When agreed |
| PPAP | Support automotive or customer-specific quality planning requirements. | Project-specific |
| COC | Confirm conformity to the agreed order or specification. | When specified |
07 / Sample Approval & Change Control
Approval Is a Baseline—Repeat Production Has to Preserve It
For repeat OEM projects, the approved sample, manufacturing route, control points and records become the reference for later batches—not just the first inspection report.
FAI / Sample Approval
The agreed first article, dimensional results and project-specific records confirm the manufacturing route before repeat production.
Change Control
Material, tooling, process, supplier or drawing changes should be reviewed before they alter the approved production and inspection baseline.
Repeat-Batch Control
Maintain the approved process window, critical checkpoints and required records for subsequent production batches.
Nonconformance & Corrective Action
When a deviation occurs, contain the affected parts, identify the failed requirement and define corrective action before release or repeat production continues.
08 / Manufacturing-Specific Quality
Each Manufacturing Route Creates Different Quality Risks
Investment Casting
Focus on alloy identity, wax/shell-related consistency, casting integrity, critical cast dimensions and machined interfaces.
View Capability →Sand Casting
Focus on pattern/core condition, casting integrity, machining stock, pressure-related features and finished machined interfaces.
View Capability →Die Casting
Focus on tooling/process-window stability, repeatability, porosity-sensitive zones, trimming, secondary machining and functional interfaces.
View Capability →Forging
Focus on material identity, forging condition, heat treatment, hardness/mechanical requirements, NDT and machined interfaces.
View Capability →CNC Machining
Focus on datum relationships, GD&T, bores, fits, threads, surface roughness, first-part approval and final dimensional records.
View Capability →
09 / Applications
Quality Priorities Change with the Finished Component.
A pump casing, hydraulic component, agricultural part and automotive component may need very different control points even when made from similar materials.
10 / Quality FAQ
Quality Control, Inspection & Documentation FAQs
Yes. The drawing, specifications and agreed quality requirements can be used to define the inspection scope for the project.
Yes. Critical dimensions, holes, threads, bores, mating surfaces and other specified features can be included in the inspection plan.
Yes. If material certification or other material records are required, they should be identified during quotation and technical review.
Yes. Providing the drawing, specifications, critical characteristics and required documentation before quotation helps establish the correct manufacturing and inspection route.
11 / Manufacturing & Quality Review
Discuss Quality Requirements →
Send the Drawing Together with the Quality Requirements
Reliable manufacturing requires more than dimensional measurement at the end of production. TIANHUI MACHINE applies quality inspection throughout the manufacturing process, including material verification, dimensional inspection and final checks. Our China factory supports inspection documentation and customer-specific requirements to help OEM buyers maintain consistent component quality.
Send the drawing, material specification, critical characteristics, acceptance criteria and required reports. We will review the verification methods, control points and documentation scope together with the manufacturing route before quotation and production.