Injection Molding SPI surface finishes
Publish Time: 2020-01-21 Origin: Site
| Finish | SPI* standard | Finishing Method | Typical surface roughness Ra (μm) |
| Super High Glossy finish | A-1 | Grade #3, 6000 Grit Diamond Buff | 0.012 to 0.025 |
| High Glossy finish | A-2 | Grade #6, 3000 Grit Diamond Buff | 0.025 to 0.05 |
| Normal Glossy finish | A-3 | Grade #15, 1200 Grit Diamond Buff | 0.05 to 0.10 |
| Fine Semi-glossy finish | B-1 | 600 Grit Paper | 0.05 to 0.10 |
| Medium Semi-glossy finish | B-2 | 400 Grit Paper | 0.10 to 0.15 |
| Normal Semi-glossy finish | B-3 | 320 Grit Paper | 0.28 to 0.32 |
| Fine Matte finish | C-1 | 600 Grit Stone | 0.35 to 0.40 |
| Medium Matte finish | C-2 | 400 Grit Stone | 0.45 to 0.55 |
| Normal Matte finish | C-3 | 320 Grit Stone | 0.63 to 0.70 |
| Satin Textured finish | D-1 | Dry Blast Glass Bead #11 | 0.80 to 1.00 |
| Dull Textured finish | D-2 | Dry Blast #240 Oxide | 1.00 to 2.80 |
| Rough Textured finish | D-3 | Dry Blast #24 Oxide | 3.20 to 18.0 |
| As machined | - | Finished to the machinist's discretion | 3.20 (with visible machining marks) |
* : SPI (Society of Plastic Industry) standards