When it comes to cost-effectiveness for manufacturing custom china keychain, some of the most affordable methods are:
Stamping/Embossing
A metal or plastic die press forms designs by imprinting shapes. Low fixed cost tooling makes high volumes very cheap per unit.
Injection Molding
Liquid plastic is injected into shaped cavities to form products. Upfront molds are expensive but per-keychain costs become quite low at high production counts.
Pad Printing
Quickly prints various designs on flat surfaces. Cheap consumables and less skill needed than other processes. Good for mid-size runs.
Laser Engraving
Very precise but high-powered lasers are pricey to purchase. Good volumes are necessary to offset costs. Competitive when used for multiple products.
Casting
Liquid metal is poured into reusable molds. Typically used for metallic keychains or charms. Affordable for small-large orders depending on molds.
Enameling
Powdered glass melts onto metal to add vibrant colors. Economical if same design applied repeatedly over large production.
Avoid niche processes like etching, CNC or jewelry-like detailing if minimizing costs is paramount. For best rates look at factories with dedicated keychain production capabilities rather than one-off custom orders.