SPI Finish Guide

SPI Finish Guide is known as SPI Mold Finish Guide or SPE-SPI Mold Finish Guide. The complete SPI finish standard covers 12 grades from SPI A1 to D3. At below SPI finish chart, we use surface roughness Ra (μm), finishing methods, recommended steels as references to show each grade’s finish.

The SPI Finish Guide could refer to the plaques made by this standard. They are available in both plastic and steel. Learn more from this link: SPI Mold Finish Guide Plaque.

SPI Finish StandardSurface Roughness Ra (μm)Finishing MethodFnishing LookSteels Recommended
SPI A10.012 to 0.0256000 Grit DiamondSuper High Glossy finishS136 (54HRC) or 8407(52HRC)
SPI A20.012 to 0.0253000 Grit DiamondHigh Glossy finishS136 (54HRC) or 8407(52HRC)
SPI A30.05 to 0.101200 Grit DiamondNormal Glossy finishS136 (300HB) or 718H
SPI B10.05 to 0.10600 Grit PaperFine Semi-glossy finish718H
SPI B20.10 to 0.15400 Grit PaperMedium Semi-glossy finish718H
SPI B30.28 to 0.32

320 Grit PaperNormal Semi-glossy finish718H
SPI C10.35 to 0.40

600 Grit StoneFine Matte finish718H
SPI C20.45 to 0.55400 Grit StoneMedium Matte finish718H
SPI C30.63 to 0.70320 Grit StoneNormal Matte finish718H
SPI D10.80 to 1.00

Dry Blast Glass BeadSatin Textured finish718H
SPI D21.00 to 2.80​Dry BlastDull Textured finish718H
SPI D13.20 to 18.0Dry BlastRough Textured finish718H