Grizzly H7762 - Manual (Page 21)

H7762 Heavy Duty Tool Grinder -19-
The Model H7762 only accepts Type 50 wheels
with a 1
1 ⁄
4
" bore.
Aluminum oxide and silicon carbide wheels are
marked in a somewhat uniform manner by all
major manufacturers. Understanding these mark-
ings will help you understand the capabilities of
various wheels. Always refer to the manufactur-
er’s grinding recommendations when selecting a
wheel for your project.
The basic format for wheel numbering is:
Prefix
Abrasive
Type
Grit
Size
Grade
Type
Bond
Type
Type 1 A 60 L V
The Prefix is the manufacturer’s designation for a
particular type.
The most common Abrasive Types used are A for
Aluminum Oxide and C for Silicon Carbide, and
occasionally SG for Seeded Gel.
The Grit Size is a number that refers to the size
of the abrasive grain in the wheel. The lower the
number, the coarser the wheel. Grit sizes range
from 10, which is a very coarse grit used for
roughing, to 220, which is usually the upper range
for fine finish work.
Grade is an indication of the hardness of the
wheel—“A” being the softest and “Z” being the
hardest.
Bond Type refers to the type of bonding material
used to hold the abrasive material. Most general
purpose wheels will have a “V” indicating Vitrified
Clay is used. Vitrified Clay provides high strength
and good porosity. The other common bond type
is “B” for resin where synthetic resins are used.
These are used to grind cemented carbide and
ceramic materials.
There may be other numbers inserted that have
meaning for a particular type of wheel. Refer to
the manufacturer’s technical data for a complete
explanation.
Wheel Inspection
Before mounting a new grinding wheel, it must
be inspected. DO NOT assume that a wheel is
in sound condition just because it is new—often,
damage can occur during shipping, with age, or
with exposure to moisture.
The most effective way to check for damage is to
give the wheel a
Visual Inspection. Look for any
cracks, chips, nicks, or dents in the surface of the
wheel. If you see any of these, however minor,
DO NOT use the wheel. Ideally a new grinding
wheel will be in almost flawless condition.
Wheel Selection
The wheel guard assembly must be removed in
order to mount or dismount a grinding wheel.
To remove/mount a wheel:
1. DISCONNECT MACHINE FROM THE
POWER SUPPLY!
2. Remove the work table by unscrewing the
two hex nuts on the underside of the table.
3. Unscrew the four bolts that fasten the grind-
ing wheel to the connector plate.
4. Carefully slide the grinding wheel free from
the arbor.
The hazards of using a damaged wheel
include flying chunks of sharp abrasive
material that could cause serious injury or
death. Inspect every grinding wheel before
it is mounted and DO NOT use a damaged
grinding wheel!
Replacing Wheels