What Is MIM Lot Number? Batch Number? Date Code? How They Are Assigned

Every MIM production lot carries a unique identifier that tells the manufacturer — and the customer — exactly when and where the parts were made, and from which raw materials.

What a MIM lot number typically contains:
Segment Example What It Identifies
Material code 316L Alloy grade
Powder lot PL-24056 The specific powder atomization batch
Feedstock batch FB-24103 The specific feedstock compounding batch
Molding run MR-24105-A The injection molding run and cavity (A = cavity 1)
Sintering batch SB-2415 The sintering furnace load
Date code 240612 Manufacturing date (YYMMDD format)
Full example: 316L-PL24056-FB24103-MR24105A-SB2415-240612

This tells the manufacturer: 316L parts from powder lot 24056, feedstock batch 24103, molded in run 24105 cavity A, sintered in batch 2415, produced on June 12, 2024.

How lot numbers are assigned:
  1. Powder lot: Assigned by the powder supplier (or by ATMIK's in-house atomization line) — one lot per atomization run
  2. Feedstock batch: Assigned by the compounding operator — one batch per compounding run (typically 25-200 kg)
  3. Molding run: Assigned per production order — each run may produce 5,000-100,000+ parts depending on cavity count
  4. Sintering batch: Assigned per furnace load — the sintering batch number is the primary traceability link because all parts in a sintering load share the same thermal history
Date codes: Many MIM suppliers also mark each part with a date code (typically 4 digits: YYWW = year + week number) for quick visual identification without needing the full lot number. Quick Q: What is a MIM lot number and how is it structured?

A MIM lot number is a unique identifier that encodes the material, powder lot, feedstock batch, molding run, sintering batch, and date. A complete lot number allows a manufacturer to trace any defective part back to its specific powder lot, molding parameters, and sintering profile — critical for root cause analysis and quality recalls. Typical format: Material-Powder-Feedstock-Mold-Sinter-Date.

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