First Principles of Inspection

What is Quality?

Quality is a process integral to our business, ensuring that each component meets both the drawing specifications and customer requirements.

The key requirements are:

• Dimensional, verifying that all dimensions fall within the specified tolerances
• Visual, confirming that the overall condition of the component meets the required standards
• Material, ensuring the correct material is used and is in optimal condition

• Further subcontract processes, covering additional services such as plating, powder coating and deburring

Quality Control  

Quality control is the final stage of the manufacturing process, ensuring that all components meet the required standards before being delivered to customers.

Quality Assurance

Quality assurance begins at the start of the manufacturing process, during the new product introduction (NPI) phase, where all potential risks are identified and addressed to prevent issues.

The goal of this process is to ensure that only conforming parts are produced and that the product is fit for use. However, in the event of discrepancies, a Plan-Do-Check-Act (PDCA) cycle can be implemented to drive continuous improvement in the process.

Direct measurement

Direct measurement involves physically measuring a component using various measurement tools. This method provides an exact value for the dimension being assessed.

Comparative measurements

This type of measurement compares a dimension to a known standard, indicating whether the dimension is within tolerance without providing the exact size.

Direct measurement equipment:

• Micrometre
• Height gauge
• Drop clock
• Bore micrometre

Comparative measurement equipment:

• Plug gauges
• Screw plug gauges
• Ring gauges
• Ring threads gauges
• Visual surface roughness comparators

How gauges are controlled

Technoset utilises a range of gauges for in-process checks, first-off inspections, and batch inspections. These gauges are tracked using the data track MRP system, which ensures they are booked in and out as needed. The system features a dedicated module that manages gauge issuing and calibration, ensuring accurate tracking of gauge locations and calibration status.

It also controls calibration requirements and scheduling, guaranteeing that all components are measured against precise and reliable attributes. Additionally, the system alerts users when measurement equipment is approaching its calibration date or is out of calibration.

• Once a job is planned and the appropriate machine is selected, the operator sets the machine to produce a dimensionally and visually correct component, following the in-process inspection checklist, which specifies the measurement equipment used for particular dimensions.
• When the component is within tolerance and meets the required standards, the setter submits it to the quality department for inspection.
• Upon receiving the component, the inspector reviews all relevant documentation, including material certification, the latest drawing revision, and any known or previous non-conformances.
• After verifying the paperwork, the first-off inspection begins. This includes a detailed visual check for burrs, surface finish quality, damage, and correct orientation, using a Mantis Elite microscope capable of 15x magnification.

• Next, the inspector measures the component’s dimensions against the setter’s recorded values to ensure accuracy, using the same instruments as the setter and logging the results in the inspection checklist.
• During measurement, the goal is for the dimensions to align with the nominal value. If discrepancies are found, the inspector records the dimensions and the deviation from tolerance, reports the issue to the setter for correction, and assesses how the measurement was initially completed. The setter rectifies the issue, and the component is re-submitted for another first-off inspection.
• For the component to pass inspection, all requirements, including material, revision, dimensions, and visual standards, must be met.
• Once the inspector is satisfied with the component, it is retained as a sample for future reference for a predefined period. Only then is the component approved for full production.

Once the first-off inspection is complete and the component is approved, production begins. The machinist receives an in-process inspection sheet, which outlines the specific timescales for performing checks. Depending on the job, certain features may require 100% verification of specific dimensions as outlined on the drawings and checklist.

Twice a day, each machine submits a component, which is first checked by the operator. An inspector then verifies the measurements to ensure they are accurate and that the component is being manufactured to the correct specifications. If any issues are identified, they can be quickly addressed and resolved.

At the end of the machining process, components are submitted for final inspection before dispatch. The inspection process may vary based on customer requirements. If any non-conforming parts are identified, production is halted until the issue is resolved. The entire batch is then re-checked to ensure all non-conformities are identified and addressed.