Wheel Inspection; Wheel Selection - Grizzly T27400 Owner's Manual

Wheel Inspection

DO NOT assume that a wheel is in sound condi-
tion just because it is new. Often, damage can
occur during shipping, with age, or with exposure
to moisture. Before installing any grinding wheel,
it must always be inspected for damage. A dam-
aged grinding wheel can fly apart at high speeds,
throwing pieces of abrasive at the operator or
bystanders with dangerous force.
First, do a Visual Inspection. Look for any
cracks, chips, nicks or dents in the surface of the
wheel. If you see any of these, DO NOT use the
wheel.
Second, do a Ring Test. This test will give you an
indication of any internal damage that may not be
obvious during a visual inspection.
A damaged grinding wheel can fly apart
and eject chunks of abrasive material with
great force, causing serious injury or death.
Inspect every grinding wheel before it is
mounted. DO NOT use a damaged grinding
wheel!
To perform a ring test:
1. Make sure wheel is clean and dry; otherwise,
you may get false results.
2. Hang the wheel in the air with a piece of cord
or string looped through hole in center. If this
is not possible, balance wheel with your fin-
ger in hole.
STOP
Rated 3500 RPM
Make sure your grinder is not
faster than the rated RPM of this wheel
Type-1
Aluminum
Oxide
WARNING
Grinding can be dangerous
Visually inspect this wheel
for cracks, nicks,chips
Figure 8. Ring test tapping locations.
-18-
60 Grit
Grade L
Vitrified Bond
3. At points shown in Figure 8, gently tap grind-
ing wheel with light, non-metallic device such
as handle of screwdriver or a wooden mallet.
4. An undamaged grinding wheel will emit a
clear metallic ring or "ping" sound in each of
these spots. A damaged wheel will respond
with a dull thud that has no clear tone.
5. If you determine from the ring test that the
grinding wheel is damaged, DO NOT use it!

Wheel Selection

The Model T27400 accepts Type 1 grinding
wheels with a ⁄ "–1" bore. Included with the tool
1
2
grinder is an aluminum-oxide wheel for grinding
HSS. A diamond wheel is also available for grind-
ing carbide steel (see Accessories on Page 25).
Generally, grinding wheels are marked in a uni-
form manner by most major manufacturers.
Understanding these markings will help you
understand the capabilities of various wheels.
Always refer to the manufacturer's grinding rec-
ommendations when selecting a wheel for your
project.
The basic format for wheel numbering is:
Abrasive
Prefix
Type
Type 1 A
The Prefix is the manufacturer's designation for a
particular type of grinding wheel.
The Grit Size refers to the size of the abrasive
grain in the wheel. The smaller the number, the
coarser the wheel. Grit sizes range from 8, which
is a very coarse grit used for roughing, to 220,
which is generally 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 have a "V" indicating vitrified clay,
which provides high strength and good porosity.
Model T27400 (Mfd. Since 02/15)
Grit Grade Bond
Size Type Type
60 L V