TYPE OF FINISHPART-ICAL SIZECURRENT SPI FINISH NUMBERSDESCRIPTIONPREVIOUS SPI FINISH NUMBER
“HIGH POLISH” DIAMOND BUFF FINISHES#3
#6
#15
A1
A2
A3
IS COMPARABLE TO IS SLIGHTLY FINER THAN HAS MORE IMPERFECTIONS THAN#1
#2
#2
“PAPER FINISHES”600
400,
320
B1
B2
B3
IS FINER THAN IS SLIGHTLY FINER THAN IS COMPARABLE TO#3
#3
#3
“STONE FINISHES”600
400
320
C1
C2
C3
IS FINER THAN IS SLIGHTLY FINER THAN IS COMPARABLE TO#4
#4
#4
“DRY BLASTED” FINISHES#11*
#240Ψ
#24Ψ
D1
D2
D3
IS FINER THAN IS COMPARABLE TO IS A LITTLE MORE COARSE THAN#5
#5
#5

There are no new finishes that are comparable to the old #6 finish.  The #6 blast process had the potential of deteriorating mold-parting lines, inserts, pockets, etc.  It is suggested if the #6 level of coarseness is desired it would be best to evaluate a photo etch texturing process, or EDM finish equivalent.

* glass bead mesh size
Ψ  oxide mesh size