In our line of work, a mold is the tooling that shapes parts through injection, blow, extrusion, die casting, forging, smelting, or stamping—and it directly sets the dimensional accuracy and batch-to-batch consistency of the product. That is why quoting a mold starts with classifying it correctly. A single-cavity prototype tool in P20 pre-hardened steel behaves nothing like a 64-cavity production tool in H13 or S136. For high-volume injection work, hardened grades such as S136 (corrosion-resistant, ~48-52 HRC after heat treatment) or 718H for large cores are common; die casting dies usually go to H13 (1.2344) because it holds up under thermal fatigue at 600-700°C melt contact. Stamping dies split by function too: blanking and piercing inserts in SKD11 or Cr12MoV, drawing dies in cast iron or alloy steel depending on draw depth. Getting the class right at RFQ stage avoids the classic mistake of quoting a production tool at prototype prices, or the reverse.
Material selection is where most cost overruns hide. A few rules I apply on the floor: match steel hardness to shot count—under 100k shots, pre-hardened 718H or P20 is usually enough; beyond 500k, go hardened S136 or H13 with proper heat treatment and stress relief. Cavity count drives steel grade as much as volume does, because a 32-cavity tool multiplies every wear point. Cooling layout matters just as much as the steel: conformal or baffled cooling in the core can cut cycle time 15-25% on thick-wall parts, and that saving often pays back the higher tooling quote within a year. Don't overlook surface treatment—nitriding or PVD coating on slides and gates extends maintenance intervals noticeably in glass-filled nylon jobs, where abrasion eats standard steels fast.
For buyers comparing quotes, ask for the steel grade, hardness, cavity count, and expected shot life in writing—those four numbers explain most price gaps between suppliers. A tool quoted 30% cheaper usually differs in one of them, and the gap shows up as downtime later. If you want to cross-check suppliers or benchmark tooling specs before committing, visiting MoldSo (www.moldso.com) gives you sourcing information and mold supplier references to compare against your own RFQ data.