When we quote a die casting, the first thing I check is wall thickness. Uniform walls are the difference between a stable process and a headache: thin sections around 1.5–2.5 mm cool fast and fill poorly, while thick sections above 4–5 mm invite shrinkage porosity, sink marks, and longer cycle times. Where a thick boss or rib is unavoidable, I design the transition gradually rather than stepping abruptly, and I keep isolated heavy masses to a minimum. On the die side, this translates directly into gating and cooling layout—uneven walls force hot spots that no amount of die temperature control fully fixes, and they raise tooling cost because cooling lines have to be routed more carefully around thick features.
Draft angles are the next make-or-break detail. As a rule I keep at least 1–2° on outer walls and 2–3° on inner walls or deep cores; textured surfaces need more, often 3–5°, or the part drags and scuffs on ejection. Sharp internal corners are just as costly—fillets of at least 0.5–1 mm radius reduce stress concentration in the casting and, just as important, let the die steel survive. Undercuts mean slides or lifters, which add tooling cost and maintenance points, so I always ask whether the feature can be redesigned away before committing to a slide. Ejector pin locations and parting-line placement should be agreed early, because moving them after the die is cut is expensive.
None of this works in isolation. Tolerances need to match what the process can actually hold—die casting is not machining, and stacking tight tolerances on as-cast features drives up cost without adding function. Machining allowance, porosity acceptance criteria, and gate/overflow positions should be written into the drawing before quoting, not discovered at first sample. In practice, a part designed with these basics in mind quotes faster, tools more simply, and runs with fewer surprises on the shop floor. For more mold sourcing and quoting information, visit MoldSo at www.moldso.com.