A Real Technical Gap On Production Site A Japanese-invested mold factory based in Dongguan employed Mr. Tanaka, a senior Japanese technician with 22 years of working experience. His core expertise was precision punch inner-hole EDM processing, which required ultra-strict taper tolerance controlled within 0.005 mm.   After Mr. Tanaka retired and returned to Japan, three technicians took over his workstation one after another, yet none could deliver qualified products:   l The first operator: Taper reached 0.012 mm, all workpieces scrapped; l The second operator: Carbon residue covered the hole wall, rejected by clients; l The third operator: Only achieved 0.008 mm taper, with a 3-day delivery delay. The factory had no choice but to outsource the entire batch to a precision mold factory in Hong Kong at three times the original price.   This case is far from unique. Over the past five years, nearly all Japanese-funded mold factories in the Pearl River Delta and Yangtze River Delta have faced identical troubles. Once senior Japanese craftsmen leave, the yield and efficiency of their stations drop drastically, and the technical gap cannot be filled quickly.   The Unique Tacit Skills Possessed by Mold Masters Most people simply define the masters’ competitiveness as vague "craftsmanship" or "intuition". Taking EDM processing as an example, their exclusive practical capabilities can be divided into three clear parts:   Predictive Compensation for Electrode Wear Ordinary technicians follow a repetitive workflow: trial cut → measure → adjust parameters repeatedly. Veteran masters adopt a forward-thinking method: l Evaluate drawings, workpiece material, depth-diameter ratio and tolerance requirements at first sight; l Calculate electrode wear rate in advance; l Pre-set tapered compensation structure (thicker top, thinner bottom) during programming. Others need three rounds of cutting to reach standards, while masters finish processing in one pass with more stable taper accuracy.   Auditory Judgment of Chip Evacuation This capability relies on long-term on-site practice instead of blind guesswork. Senior EDM technicians judge internal machining status merely by the discharge sound of equipment: l Crisp crackle: Smooth chip evacuation; l Dull puff sound: Chips pile up, electrode lifting required; l Sudden silence: Short circuit happens, reduce servo speed instantly. This perceptual experience cannot be compiled into formal SOPs and can only be gained through years of machine operation.   Material Memory for Tungsten Carbide Machining Different tungsten carbide brands, cobalt content and sintering processes lead to completely different EDM performance. Senior technicians who stay in one factory for over a decade form unique material muscle memory. Faced with new tungsten carbide grades, they adjust current parameters immediately by distinguishing spark color and discharge sound.   In contrast, young technicians frequently switch processing materials between SKD11, tungsten carbide and powder high-speed steel. They never get enough time to master the processing characteristics of a single material thoroughly. Three Root Causes for Failed Skill Inheritance Young generations are not unwilling to work hard; the core problems lie in the flawed industrial operation system.   Collapsed Systematic Training Mechanism The standard growth path of Japanese mold technicians is long and complete: 3-year apprentice → 5-year assistant → 10-year independent operator → professional craftsman. The system includes standardized apprenticeship, regular skill assessment and rotational training.   However, domestic mold factories face tight order deadlines. New apprentices are required to operate machines independently after only 3 months of learning, with no time for slow, systematic skill training.   Tacit Experience Cannot Be Digitized Most of the masters’ core experience is unquantifiable tacit knowledge: l Slow down servo speed by 15% for certain holes; l Increase flushing pressure by 0.2 MPa for specific materials; l Severe electrode wear appears on the third arc section of special electrode shapes. These real-time adjustment rules cannot be written into CNC codes or teaching videos. Once the senior technician leaves, the valuable experience disappears completely.   Declining Industry Attractiveness for Young People Young job seekers have more career options nowadays. Food delivery, live streaming and e-commerce provide cleaner working environments with similar entry salaries. Most young workers regard mold workshops as a temporary job, and few intend to devote 20 years to precision machining. Feasible Solutions to Solve the Skill Gap Crisis There is no perfect one-step solution, yet three practical directions can help factories retain and pass down veteran experience:   Build a Complete Machining Experience Database Record full dimensional data of every mold batch, including EDM parameters, material batches, electrode wear rate and final taper measurement results. Establish a searchable "material-parameter-processing result" comparison table for new operators to reference and reduce blind trial and error.   Combine Standardized Operation with Adjustable Flexibility Avoid locking all processing parameters rigidly. Set unified baseline parameters with clear adjustable ranges, and mark corresponding adjustment logic under different machining conditions. This balances standardization and flexible on-site judgment.   Train Multi-skilled Compound Technicians Break single-station fixed work mode. Encourage EDM operators to learn wire cutting, surface grinding and mold assembly. Workers with comprehensive cross-process knowledge can solve complex machining problems better and are less replaceable.   Japanese mold masters’ irreplaceable capacity is not some mysterious super skill. The real crisis is that decades of accumulated experience has never been recorded, standardized or passed down systematically.   This technical succession dilemma troubles the whole precision manufacturing industry, not individual factories. If enterprises ignore experience inheritance at present, we will face the same huge gap when our current senior workers retire.   The core question every mold manufacturer must answer: Who will take over our accumulated craftsmanship in the future?