ForMatter/Finishes/mold_finish/SPI B2 (medium paper polish, 400-grit)
finish_mold_spi_b2

SPI B2 (medium paper polish, 400-grit)

mold_finish · polished · SPI B-2, medium semi-gloss mold finish

A 400-grit emery paper polish on the mold cavity — between B1 (600-grit, fine) and B3 (320-grit, coarse). Reads as medium semi-gloss on the molded part; reasonable defect-hiding without going matte. The middle of the SPI B series.

SPI / SPE finish B2 — 400-grit emery paper polish on tool-steel cavity. Surface roughness Ra ~0.2–0.3 µm. Sits between B1 (600-grit, ~0.1–0.2 µm) and B3 (320-grit, ~0.4 µm). All B-series semi-gloss; molded parts read soft sheen with mild defect-hiding. Cheaper than A-series; common spec on mid-tier consumer-product housings, household-goods bodies, kitchen-appliance shells.

character — medium semi-gloss, the middle of the SPI B family.

Finish properties

  • levelpolished
  • subcategorySPI / SPE paper polish — medium
  • Ra (µm)0.25
  • applies topolymer
Produced by processesInjection Molding

Second life

reversibilityzero on the molded part — the mold-cavity surface is transferred at the moment of forming and cannot be undone without re-molding from a different cavity.
blocks substrate recyclingno
renewabilityzero on the existing part; the mold cavity itself can be re-polished or re-textured by the toolmaker for subsequent runs.

SPI / SPE Mold Surface Finish standards (A-1 through D-3); VDI 3400 mold-cavity texture reference plates.

Citations

  • standard · SPI/SPE Mold Finish Standards (Society of the Plastics Industry, AB-3) — B1 / B2 / B3 paper-polish reference.