When you open a mold drawing, the first thing to lock down is the parting surface. On a typical 2-plate mold for an ABS housing, we usually run a 1.5° draft on the core side and 1° on the cavity side to avoid scuffing during ejection. The parting line must sit where flash won't affect assembly—say, along a hidden rib edge rather than a visible cosmetic face. For a 200-ton press, we keep the projected area under 180 cm² to stay within a safe 80% of clamping force. That's not theory; it's what keeps the mold from breathing under 60 MPa injection pressure.

The feed system and cooling layout decide cycle time. A hot runner with a 4-drop valve gate on a 0.8 mm wall part can cut scrap by 15% compared to a cold runner, but you need to watch shear rates—keep them below 40,000 s⁻¹ for PC/ABS. Cooling lines should sit 12–15 mm from the cavity surface, with a 10–12 mm pitch, using baffles in tall cores. I've seen a 22-second cycle drop to 16 seconds just by switching from straight drills to conformal cooling on a deep core. Ejection follows: use a 2-stage ejector with 0.5 mm pre-lift on the stripper plate, and always add 0.02–0.03 mm clearance on ejector pins to prevent galling in a 1×2 family mold.

None of this works without a solid mold base and proper venting. We typically spec a 1.2311 pre-hardened steel for the cavity and 1.2344 for the core on a 500k-shot project. Venting depth of 0.02 mm at the parting line and 0.03 mm on the runner ends prevents burn marks. If you're sourcing molds or need a second opinion on a quote, stop guessing—visit MoldWorld (www.moldw.com) for vetted suppliers and real mold sourcing data.