Grinding Wheels

GRINDING WHEELS (from Jerry Johnson)

Abrasive Types: 
 A = aluminum oxide
 C = silicon carbide
 Z = aluminum-zirconium oxide

Bond Type:
 B = resinoid
 BF = resinoid reinforced
 O = oxychloride
 R = rubber
 RF = rubber reinforced
 S = silicate
 V = vitrified
 SG = seeded gel

Abrasive Size:
 Coarse: 8, 10, 12, 14, 16, 20 and 24 grit
 Medium: 30, 36, 46, 54, 60
 Fine: 70, 80, 90, 100, 120, 150, 180
 Very Fine: 220, 240, 280, 320, 400, 500, 600

Grade Scale:
 ABCDEFGHIJKLMNOPQRSTUVWXYZ
 Soft                 Medium               Hard
 High Speed                           Mild Steel
    Steel

Structure:
 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
 Dense                                    Open

So, a A80H8V wheel is aluminum oxide, 80 grit, relatively soft, with a medium density of abrasives and is vitrified.

Preferences:
 Mike Mahoney and Martin Pidgen use a 46G.
 Stuart Batty uses 60 grit for gouges and 80 grit for scrapers

Speed of Grinder:  Mike M, Martin P, Stuart B and Bonnie Klein all use 3400 rpm grinders while Lyle Jamison and John Jordan use 1750 rpm.