Disc inspection service

Disc Inspection Service – Accredited ISO/IEC 17025 Non-Destructive and Dimensional Testing for the Colombian Market

Discs and circular components are critical elements in a wide range of industrial, automotive, aerospace, oil and gas, and power generation applications. Brake discs, turbine discs, compressor discs, clutch plates, flanges, and circular seals must meet stringent quality, safety, and performance standards to ensure reliable operation, prevent catastrophic failures, and maintain regulatory compliance. The accurate inspection of disc components is essential for detecting surface defects, dimensional deviations, material inconsistencies, and internal flaws that could compromise their integrity. In the Colombian market, where the Superintendencia de Industria y Comercio (SIC), the Ministerio de Transporte, the Ministerio de Minas y Energía (MinMinas), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce strict quality and safety standards for industrial components, the thorough inspection of discs is essential for product certification, supplier qualification, quality control in manufacturing, and import-export processes. Our laboratory offers a comprehensive disc inspection service, applying a combination of non-destructive testing (NDT) methods, dimensional measurement, surface roughness analysis, hardness testing, and material verification to ensure that every disc meets the required specifications. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them indispensable for regulatory compliance, asset integrity management, and market access in Colombia.

Disc Components and Materials We Regularly Inspect

Our laboratory receives a wide variety of discs and circular components for inspection. Typical samples include:

• Brake discs and rotors – for automotive, railway, and industrial braking systems.
• Turbine discs – for gas turbines, steam turbines, and jet engines.
• Compressor discs – for axial and centrifugal compressors in oil, gas, and power generation.
• Clutch plates and friction discs – for automotive and industrial transmissions.
• Flanges and circular seals – for pipe connections and sealing applications.
• Gear blanks and circular drive plates – for power transmission systems.
• Prototype and new disc designs – submitted by manufacturers for validation of quality and performance before series production.
• Discs retrieved from field service – for failure analysis and remaining life assessment.

Dimensional Inspection – Verifying Geometric Conformance

Dimensional inspection is the most fundamental step in disc inspection, ensuring that the disc conforms to the specified design and tolerances. Our dimensional inspection services cover all critical dimensions, including diameter, thickness, flatness, parallelism, concentricity, and hole locations, using a combination of manual and coordinate measuring machines (CMM).

• Coordinate measuring machine (CMM) inspection (ISO 10360 / NTC 4900 – for complex geometries) – the disc is mounted on a CNC CMM, and a calibrated probe (touch trigger or scanning) is used to measure the key dimensions (outer diameter, inner diameter, thickness, flatness, parallelism, concentricity, hole positions, and angular features). We report the measured dimensions, the deviations from the design specification, and the pass/fail status for each dimension. The measurement uncertainty is calculated and reported.
• Manual dimensional inspection (NTC 4901 – for simple geometries and large parts) – for large discs or simpler geometries, we use calibrated micrometers, calipers, dial gauges, and height gauges to measure the diameter, thickness, flatness, and parallelism. We report the measured values and the compliance with the tolerances.
• Optical comparator inspection (NTC 4902 – for small discs and features) – for small discs and for detailed inspection of edge profiles, holes, and surface features, we use an optical comparator with a digital readout. The disc is projected onto a screen, and the dimensions are measured with high precision. We report the measurements and the deviations from the drawing.
• Surface profilometry and roughness measurement (ASTM D7127 / NTC 4903 – for surface finish assessment) – we measure the surface roughness (Ra, Rz, Rmax) of the disc surface, especially on the friction surface of brake discs and on the sealing surfaces of flanges. We use a contact profilometer or a non-contact optical profiler. We report the roughness values, the required finish, and the pass/fail status.
• Flatness and parallelism measurement (NTC 4904 – for critical sealing surfaces) – we measure the flatness and parallelism of the disc surfaces using a dial indicator on a precision surface plate, or using a CMM. This is critical for brake discs, clutch plates, and flange sealing surfaces. We report the flatness and parallelism values, and the compliance with the tolerance.

Non-Destructive Testing (NDT) – Detecting Internal and Surface Defects

Non-destructive testing is essential for identifying internal and surface defects in discs that are not visible to the naked eye. Our NDT services cover the full range of methods, including ultrasonic testing, magnetic particle inspection, dye penetrant inspection, and radiographic testing, to detect cracks, voids, inclusions, and other discontinuities that could lead to failure under service conditions.

• Ultrasonic testing (UT) – ASTM E164 / NTC 4910 – for internal flaw detection – we use ultrasonic testing (pulse-echo or through-transmission) to inspect the disc for internal defects (cracks, voids, inclusions, and delaminations). The disc is scanned using a contact transducer or an immersion technique, depending on the geometry. The size and location of any indications are recorded. We report the defect location, size, and interpretation (pass/fail).
• Magnetic particle inspection (MPI) – ASTM E1444 / NTC 4911 – for surface and near-surface cracks in ferromagnetic materials – for ferromagnetic discs (steel, cast iron), we perform MPI to detect surface and near-surface cracks. The disc is magnetized, and a magnetic particle suspension is applied. Cracks are revealed by the accumulation of particles. We report the location, length, and severity of any indications.
• Dye penetrant inspection (DPI) – ASTM E165 / NTC 4912 – for surface cracks in all materials – for non-ferromagnetic discs, or as a preliminary inspection, we perform dye penetrant testing. A penetrant dye is applied to the surface, allowed to dwell, and then removed. A developer is applied, and any cracks are revealed by the bleed-out of the dye. We report the location, length, and severity of any indications.
• Radiographic testing (RT) – ASTM E94 / NTC 4913 – for volumetric inspection – for complex or thick discs, we perform radiographic testing (X-ray or gamma-ray) to inspect the internal structure for voids, inclusions, and cracks. The disc is placed between a radiation source and a film or a digital detector. We report the type, size, and location of any defects observed.
• Eddy current testing (ECT) – ASTM E376 / NTC 4914 – for surface and near-surface defects in conductive materials – for conductive discs (aluminum, copper, and some steels), we use eddy current testing to detect surface and near-surface cracks, and to measure the thickness of protective coatings. We report the defect location and size.

Hardness and Material Verification – Confirming Material Properties

Hardness testing and material verification are critical for ensuring that the disc has been manufactured from the correct material and that its mechanical properties meet the design specifications. Our services include hardness testing (Rockwell, Brinell, Vickers, and Shore), material composition analysis, and microstructure examination.

• • Hardness testing (ASTM E18 / NTC 4920 – Rockwell, Brinell, Vickers) – we perform hardness testing on the disc surface and, if required, on a cross-section, to verify the hardness level (HRC, HRB, HB, HV). Hardness is correlated with the strength and wear resistance of the disc. We report the hardness values, the average, and the variation across the disc.
  • Chemical composition analysis (ASTM E415 / NTC 4921 – for metals and alloys) – we use optical emission spectroscopy (OES) or X-ray fluorescence (XRF) to determine the chemical composition of the disc material (carbon, manganese, chromium, nickel, molybdenum, etc.). We verify that the composition matches the specified grade. We report the composition and the compliance with the grade.
  • Microstructure examination (ASTM E3 / NTC 4922 – for grain size and phase analysis) – we prepare a polished and etched cross-section of the disc and examine the microstructure using an optical microscope or a scanning electron microscope (SEM). We report the grain size (ASTM grain size number), the phase distribution (ferrite, pearlite, martensite), and any anomalies such as carbide segregation, inclusion presence, or decarburization.
  • Coating thickness measurement (ASTM B499 / NTC 4923 – for protective coatings) – for discs that are coated (e.g., with zinc, paint, or ceramic coatings), we measure the coating thickness using a magnetic or eddy-current gauge. We report the coating thickness (in μm) and the uniformity across the disc.
  • Case depth measurement (ASTM E1077 / NTC 4924 – for case-hardened discs) – for carburized or induction-hardened discs, we measure the effective case depth (the depth of the hardened layer) using microhardness testing or metallographic examination. We report the case depth (in mm) and the hardness profile.

Surface Integrity and Wear Assessment – Evaluating the Condition of the Disc Surface

The surface integrity of discs, especially for brake discs, clutch plates, and sealing surfaces, is essential for their proper function. Our surface integrity assessment includes the visual inspection, the measurement of surface roughness, the detection of surface defects (scratches, cracks, scoring), and the evaluation of wear patterns.

• Visual inspection (NTC 4930 – for surface defects and damage) – we perform a thorough visual inspection of the disc surface using an optical microscope or a borescope. We look for scratches, scoring, cracks, corrosion, pitting, or any other surface imperfections. We report the observations and the extent of the damage.
• Surface roughness measurement (ASTM D7127 / NTC 4931 – for evaluating surface texture) – we measure the surface roughness (Ra, Rz, Rq) of the disc surface, especially on the friction surfaces of brake discs and on the sealing surfaces of flanges. We use a contact profilometer or a non-contact optical profiler. We report the roughness values, the required finish, and the pass/fail status.
• Wear pattern analysis (NTC 4932 – for assessing brake disc wear) – for brake discs, we analyze the wear pattern (uniform wear, scoring, grooving, or hot spots) using visual inspection, dimensional measurement, and roughness analysis. We report the wear pattern and the residual thickness of the disc.
• Corrosion assessment (NTC 4933 – for discs exposed to corrosive environments) – we inspect the disc for signs of corrosion (pitting, rust, or scaling) using visual inspection and microscopic examination. We report the type, extent, and severity of the corrosion.
• Runout and thickness variation measurement (NTC 4934 – for rotating discs) – for rotating discs (e.g., brake discs, turbine discs), we measure the axial runout (or the radial runout) and the thickness variation using a dial indicator on a precision support. We report the runout (in mm) and the thickness variation (in mm), and we verify the compliance with the allowed tolerances.

Performance and Functional Testing – Simulating Service Conditions

In addition to dimensional inspection, NDT, and material verification, we also perform functional tests to evaluate the disc's performance under simulated service conditions. These tests are critical for validating the disc's ability to withstand the stresses and loads it will encounter in its intended application.

• Brake disc performance testing (NTC 4940 – for brake discs) – we simulate the braking conditions on a brake dynamometer or a test rig, applying a specified load and speed, and measuring the braking torque, the friction coefficient, the wear rate, and the temperature rise. We report the friction coefficient, the temperature, and the wear.
• Turbine disc spin testing (NTC 4941 – for high-speed rotating discs) – we spin the turbine disc at a specified speed (up to the design speed) in a spin test rig, and we measure the radial growth, the vibration, and the temperature. We report the growth and the condition of the disc after the spin test.
• Clutch disc friction and wear testing (NTC 4942 – for clutch plates) – we measure the friction coefficient and the wear rate of the clutch disc under simulated engagement cycles. The test is performed on a clutch test rig. We report the friction coefficient, the wear, and the engagement characteristics.
• Sealing surface leak test (NTC 4943 – for flanges and sealing discs) – we perform a leak test on the sealing surface (flange) using a helium leak detector or a pressure-decay test. We report the leak rate (in mbar·L/s) and the integrity of the seal.
• Thermal shock and fatigue testing (NTC 4944 – for discs subjected to thermal cycling) – for discs that are subject to rapid temperature changes (e.g., brake discs, turbine discs), we perform thermal shock tests by heating and quenching the disc, and we inspect for cracks and deformation. We report the condition of the disc after the thermal shock.

Test Report and Recognition in the Colombian Industrial and Automotive Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (CMMs, UT flaw detectors, MPI units, hardness testers, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the disc (manufacturer, part number, serial number, material, and dimensions).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, equipment used, and inspection conditions).
• Numerical results: dimensions (mm), flatness (mm), parallelism (mm), roughness (Ra, Rz), hardness (HRC/HRB/HV), coating thickness (μm), case depth (mm), NDT indications (location and size), and runout (mm).
• Graphical data: CMM inspection reports (with deviation plots), NDT images, and hardness profiles.
• Comparative tables against the values specified by the client or against the limits of the NTC 4900 (Dimensional inspection), NTC 4910 (Ultrasonic testing), NTC 4920 (Hardness), and the requirements of the SIC, Ministerio de Transporte, MinMinas, and DIAN for product certification.
• Photographs of the disc before and after the inspection, showing any defects or wear patterns.
• Recommendations for acceptance, rework, or rejection based on the inspection results.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98-3 Guide.

These reports are fully accepted by the Superintendencia de Industria y Comercio (SIC) for product registration and quality certification, by the Ministerio de Transporte for automotive component homologation, by the Ministerio de Minas y Energía (MinMinas) for the certification of equipment used in the oil, gas, and mining sectors, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of discs and circular components. Additionally, we offer consulting services for the design of robust disc inspection programs, the selection of appropriate NDT methods, and the implementation of quality control measures, contributing to the safety, reliability, and efficiency of industrial components and equipment in the diverse and growing Colombian market, from the automotive and aerospace industries to the oil, gas, and energy sectors.