Quality Control Options for CNC Machined Parts

CNC machining is known for its precision. But what’s the best way to test that precision?

Every part produced with MakerVerse undergoes a visual inspection by one of our engineering experts. Beyond that, we offer a range of optional dimensional, surface, and material property-related inspection reports and certificates. These provide different levels of insight that might be invaluable to understanding how your part will perform and how it was manufactured.

This guide will explain each choice and when they’re best suited for your part.

Material Certificate 3.1

Receive an authentic verification of the quality and composition of materials used to produce your parts, backed by an official test report. A single certificate validates the entire set in scenarios where all parts are crafted from the same material batch.

This certification process is meticulous, with each material batch undergoing stringent testing and analysis to ensure it meets the defined specifications and standards.

When to Use This: When material integrity is crucial for your project and you need official documentation to verify the material specifications and compliance.

Dimensional Measurement Report 

Ensure every detail of your CNC machined parts is up to spec with a Dimensional Measurement Report. This document provides a record of measurements and dimensions for select sample parts from your order, confirming they adhere to the specified tolerances.

Precise instruments capture the intricate details of your parts, measuring dimensions to ensure conformity. Whether it’s a complex geometry or critical dimensions, this report provides the data you need to verify that every aspect of your part meets the stringent standards required for your application.

When to Use This: This is ideal for projects where adherence to specified dimensions is paramount and a detailed report is required for quality assurance purposes.

Certificate of Conformity

Obtain peace of mind with an official Certificate of Conformity, a formal declaration that attests to your parts’ compliance with all provided requirements and specifications.

Regardless of the complexity or simplicity of your parts, the Certificate of Conformity is a stamp of approval, ensuring that every component in your order has undergone rigorous inspection and quality control procedures. Only one certificate is necessary per order, simplifying the validation process.

When to Use This: Whenever you need formal assurance that your parts have been manufactured to meet all specified requirements and standards.

Certificate of Origin

This certification is crucial for customs and trade, ensuring transparency and compliance with international trade regulations.

Whether for tariff considerations, trade agreements, or just for your records, the Certificate of Origin provides a clear and official declaration of where your parts were manufactured. This transparency is vital in today’s global manufacturing landscape, ensuring that every step of the production process is accounted for.

When to Use This: This is particularly important for international shipments and trade compliance or when the origin of the parts is a critical factor for your project.

Optical Dimensional Measurement (3D Scan)

With this option, you can compare the part’s dimensional properties to the original design. By default, the best-fit method for alignment will be used, but if necessary, your report can be adjusted to a defined reference point.

Dimensional measurements are conducted with a ZEISS Gom ATOS 12 m or similar device. First, moving fringe patterns are projected onto the part’s surface with a high-power blue light source. High-quality stereo cameras capable of high resolutions capture the reflections from the projection. Ambient non-blue light is filtered out to measure the dimensions of the printed part. When choosing a 3D scan, you’ll receive an inspection report providing false-color pictures from three angles.

When to Use This: When free-form structures or contours need to be quickly measured for accuracy

CT Scan

A CT (computed tomography) scan provides a detailed look at the part’s internal material properties. For the CT scan, the part is placed between an X-ray emitter and an X-ray detector. A tomographic reconstruction is made by emitting X-ray beams from different angles for various layers. This process provides a detailed cross-section view of the part in virtual slices.

This scan is performed according to ISO 17025 standards, which “enables laboratories to demonstrate that they operate competently and generate valid results.” This option includes the CT data for self-analysis (GOM Volume Inspect) and an expert report for an additional charge.

When to Use This: When checking the internal material properties of a metal part against potential defects, errors, pores, inclusions, or voids.

Surface Roughness Measurement

A part’s surface roughness can affect its durability, friction, and other factors, so it is essential for industrial use to get the roughness within an acceptable range.

A sensitive stylus is dragged along the surface, measuring the heights and valleys with a precision better than .03μm. The measurements are extrapolated to the entire surface, computing roughness metrics. This process is all performed according to the DIN ISO 4287 standard. You will receive a report with your part, including the heights and valleys from the path up to 50mm and the computed Rz and Ra values.

When to Use This: When the surface roughness is critical to the function of the part.