Evaluating Tooling Acceptance Criteria during Overseas Factory Acceptance Testing
Rigorous overseas tooling acceptance demands steady-state thermal runs, single-cavity Cpk validation, complete disassembly wear audits, and escrow-backed signoff.
Hardness Testing
Meaning
Empirical measurement of a material’s resistance to localized plastic deformation or indentation. Standardized hardness testing provides a numerical value that correlates with tensile strength and wear resistance in metals or polymers. This procedure involves pressing a specifically shaped indenter into the surface under a controlled load.
Scale Selection
Different testing scales like Rockwell or Vickers are used depending on the expected properties of the specimen. Proper hardness testing requires a flat and clean surface to ensure the indenter does not slip or hit an inclusion. Choosing the wrong scale leads to inaccurate readings that might hide structural flaws in a production lot.
Quality Verification
Batches of heat treated components undergo this check to confirm they meet the hardness specified in the engineering drawing. When hardness testing shows a result outside the tolerance range, it suggests a failure in the quenching or tempering process. Such parts are quarantined to prevent them from reaching the assembly line where they could fail prematurely.
Tooling Durability
Molds and cutting bits must retain their shape under extreme pressure and friction. Regular hardness testing of these assets monitors their degradation over thousands of cycles. Early detection of softening allows for re-treating or replacement before the quality of the finished product drops.
This periodic audit is the primary defense against the gradual erosion of manufacturing tolerances in high speed machining centers.