Overview SPI standard for polishingPhilipsSPISPIDiscriptionRa in pmCommentsstan dard(old)(new)(DIN)0 - UN - D 2491 - UN - D 2492 - UN - D 2493 - UN - D 2494 - UN - D 24912345A-1A・2A・3B-1B-2B-3C-1C-2C-3D-1D-2D-3Diamond buff grade 3Diamond buff grade 6Diamond buff grade 15600 grit paper400 grit paper320 grit paper600 stone400 stone320 stoneDry blast glass bead 11, 200 distance at 0.7 Mpa; 5 secDry blast 240 oxyde, 125 distance at 0.7 Mpa; 5 secDry blast 240 oxyde, 150 distance at 0.7 Mpa; 5 sec0 - 0.0250.025 ・ 0.050.05 - 0.0760.05 - 0.0760.10-0.1270.23 - 0.250.25 ・ 0.300.64-0.710.97-1.070.400.25 - 0.300.66 - 0.814.83 - 5.84For mirror or optical finishes. Most time consuming. Steel grade important to resultsRemoves all tool and machining marks. Provides good mould release. Light reflecting finish on moulded part, some sheen.Removes all tool and machining marks・ Provides good mould release. Mute finish on moulded part, no sheen.Technical Smooth, polishing only needed for proper moulding functionNo more in use.For decorative finishes. Often used for diecast and thermoset cooling. Helps hide shrink marks and other imperfections. Dull, non reflecting finish on moulded or cast part.。