Tolerance and Quality Control

Precision Starts with Clear Requirements

Not every feature requires the tightest possible tolerance. Before production, our engineering team reviews your 2D drawings, 3D models, materials, surface finishes, assembly requirements, and critical dimensions.

We identify manufacturing risks early and recommend practical tolerance ranges that balance part performance, consistency, lead time, and cost.

Critical Dimensions

Identify dimensions that directly affect assembly, movement, sealing, or product performance.

Material Behavior

Evaluate how material hardness, thermal expansion, and machining stability may influence accuracy.

Part Geometry

Review thin walls, deep cavities, small holes, complex surfaces, and other difficult-to-machine features.

Surface Finishing

Allow for dimensional changes caused by anodizing, plating, powder coating, polishing, or heat treatment.

Final tolerances should be confirmed according to the drawing, part geometry, material, manufacturing process, and quantity.

Machining Tolerance Capabilities

The achievable tolerance depends on the manufacturing process, part size, geometry, material, surface finish, and inspection method. The following values should be used as general capability references rather than guaranteed tolerances for every feature.

Quality Control Throughout Production

Inspection is integrated into the complete production process—not limited to a final check before shipment. This helps identify problems early and maintain consistent quality from the first article to repeat production.

01. Drawing and Requirement Review

Confirm materials, dimensions, tolerances, finishes, threads, appearance standards, and inspection requirements.

02. Incoming Material Verification

Check material specifications, dimensions, condition, and supporting certificates when required.

03. First Article Inspection

Inspect the first completed part before continuing production to verify setup, dimensions, and machining parameters.

04. In-Process Inspection

Monitor critical dimensions during machining to reduce deviation caused by tool wear, temperature, or fixture movement.

05. Final Inspection

Verify dimensions, appearance, quantity, surface finish, and customer-specific requirements before packaging and shipment.

Inspection Equipment

Different features require different inspection methods. Yanmee selects suitable measuring equipment according to part geometry, tolerance level, surface requirements, and customer specifications.

Coordinate Measuring Machine

Used to inspect complex geometries, position tolerances, profiles, and three-dimensional features.

Optical Measuring System

Suitable for small, delicate, or difficult-to-contact features and profile inspection.

Height Gauge

Measures part heights, steps, hole positions, and relative dimensional differences.

Micrometers and Calipers

Used for routine dimensional checks during machining and final inspection.

Surface Roughness Tester

Verifies surface texture when a specific Ra requirement is stated on the drawing.

Thread and Pin Gauges

Confirm internal threads, external threads, hole diameters, and fit requirements.

What We Inspect

Dimensions and Tolerances

Critical dimensions, hole sizes, positions, wall thicknesses, and overall geometry.

Material Verification

Material grade, specification, condition, and certificates when requested.

Geometric Accuracy

Flatness, perpendicularity, parallelism, concentricity, position, and profile.

Surface Finish

Surface roughness, machining marks, polishing quality, coating, and cosmetic consistency.

Threads and Assembly Fit

Thread specifications, inserts, mating features, interference, and clearance.

Appearance and Packaging

Scratches, dents, stains, color differences, part protection, labels, and packaging condition.

Quality Documentation

Engineering Review

Manufacturability and measurement methods are confirmed before machining begins.

Controlled Manufacturing

Suitable machines, fixtures, cutting tools, and machining sequences are selected for critical features.

Environmental Consideration

Temperature-related dimensional changes are considered when measuring high-precision metal components.

Tool Wear Monitoring

Critical dimensions are checked during production to prevent gradual deviation caused by tool wear.

Batch Traceability

Materials, production information, and inspection results can be linked to specific production batches.

Corrective Action

When a deviation is found, affected parts are isolated, reviewed, and corrected before shipment.

Industries We Support

Yanmee manufactures custom parts for projects in:

• Industrial Equipment
• Automotive
• Aerospace
• Medical Devices
• Robotics
• Industrial Automation
• Consumer Electronics
• Home Appliances

Each industry has different requirements for accuracy, materials, appearance, documentation, and traceability. Our inspection plan is adjusted according to the application and drawing requirements.