SPI A1 finish
Higher mirror band on the chart.
SPI A1 finishGlossary
What Is an SPI A2 Finish? Injection Molding Explained
SPI A2 is a high gloss SPI band used on many visible housings without full A1 mirror cost.
Glossary
SPI A2 is a high gloss finish with slightly less mirror character than A1
Many visible consumer housings land on A2 when A1 polish cost is hard to justify.
A2 still uses fine diamond polish on cavity steel but stops short of the last mirror passes A1 demands.
Pack and gate blush can still appear on A2 faces, so DFM for fill pattern matters.
Drawings should name A2 on specific faces rather than blanket gloss on every surface.
Glossary
How spi a2 finish shows up on real programs
Library photos illustrate molding and tooling context for this term.
- Use the term in RFQs with geometry and material context, not in isolation.
- Link to the design guide when the term affects steel or part design.
- Upload CAD when the term changes tooling scope or piece price.
RFQ
A2 finish notes for mold build
These keep polish scope aligned with cosmetic acceptance.
CAD faces tagged as A2 versus lower SPI bands
Gate location relative to A2 land
Parting line witness allowed or forbidden on A2 edges
Sample plaque or prior part reference if available
Go deeper
Where this term connects
Each link is a different angle on the same program, not a duplicate definition.
SPI B1 finish
Medium gloss step down.
SPI B1 finishSPI finish chart
Full A through D overview.
SPI finish chartHigh gloss polish spoke
Program level RFQ context.
High gloss polish spokeVisual reference
Photos from molding and tooling programs
Images are selected from the NetProto Forge media library for this topic.
Injection molded production parts on a tray
Injection molded production parts on a tray
Engineer reviewing a molded part drawing
Engineer reviewing a molded part drawing
Plastic housing components from a steel tool
Plastic housing components from a steel tool
FAQ
SPI A2 questions
Is A2 acceptable for lens windows?
Optical programs often need A1 or dedicated optical polish beyond SPI labels.
Can A2 and texture coexist on one mold?
Yes with shutoffs when each face is dimensioned separately.
Does resin choice change A2 appearance?
Yes. Gloss and fill pattern vary by material and color.
Next step
Document gloss bands on the drawing
Upload CAD with finish callouts before steel polish begins.