Meaning
International standard establishes the decision rules for proving that a manufactured part conforms to its dimensional specifications. Following iso 14253-1 requires that the measurement uncertainty is subtracted from the tolerance zone to create a narrower acceptance interval. This ensures that any part accepted by the quality department is definitely within the limits, even when the measurement tool has a small margin of error.
Conformance Rule
Rejection of a part happens when the measured value plus the uncertainty exceeds the upper limit or minus the uncertainty falls below the lower limit. Under iso 14253-1, the burden of proof is on the manufacturer to show that the part is good. This approach prevents the shipping of non-conforming parts that might otherwise pass if the uncertainty was ignored.
Uncertainty Budget
Calculating the margin of error involves looking at the calibration of the gauges, the temperature of the inspection room, and the skill of the operator. Implementation of iso 14253-1 forces a moulding shop to maintain high-quality metrology equipment and tight environmental controls. If the uncertainty is too large, the effective tolerance for the part becomes too small to manufacture profitably.
Contractual Clarity
Using this standard in a supply agreement prevents disputes between the moulder and the customer regarding borderline parts.
