Two molds can look almost similar on a shelf yet perform differently on the floor. One keeps running for years while the other starts flashing, sticking, and needing repairs even before the first year ends.
Steel is the first big factor. Harder grades hold fine detail and resist wear, which matters when you're running millions of cycles. Softer steels cost less and cut faster, so they suit short runs or prototypes. Neither is wrong. The mistake is choosing without knowing the production volume.
