Use and Care Manual

ManualsBrandsMilwaukee ManualsAngle GrindersM18 18-Volt Lithium-Ion Cordless 4-1/2 in. Cut-Off/Grinder with Two 4.0 Ah Batteries, Charger and Contractor Bag

WARNING To reduce the risk of injury,

the operator should be instructed in the

use, care and protection of grinding wheels.

Fig. 5

For best result use only this portion of disc

Hold at a

5° to 15°

angle

USING GRINDING WHEELS

Grinding Wheel Selection

Use grinding wheels, and accessories that are:

• correct size as written on tool’s nameplate.

• rated at or above the RPM listed on the tool’s

nameplate.

• correct accessory, wheel type and grit for the job.

Grinding is the cutting action of thousands of abra-

sive grains on the face of a grinding wheel. When

grinding metals such as steel and iron, choose an

aluminum oxide grinding wheel. Select a silicon

carbide grinding wheel for stone and concrete. Use

cotton reinforced wheels for non-ferrous metals.

Type 27 Reinforced 1/8" thick or less Cut-Off

Wheels are suited for small cut-off and shallow

notching operations only. Always handle wheels

carefully to avoid damage. Before installing any

wheel, always inspect it for cracks. If wheel is

cracked, discard it to prevent others from using it.

Care of Grinding & Cut-Off Wheels

Grinding/cut-off wheels should be protected from:

• wetness and extreme humidity

• any type of solvent

• extreme changes in temperature

• dropping and bumping

Grinding and cut-off wheels should be stored:

• in an organized way so wheels can be removed

without disturbing or damaging other wheels

• with their safety information

Grinding and cut-off wheels should NOT be

dropped, rolled or bumped.

Discard wheels that have been dropped, rolled,

bumped, subjected to extreme changes in tem-

perature, or come into contact with solvents or

wetness.

Grinding

When grinding, hold tool at a 5

to 15

angle, using

constant pressure for a uniform ﬁ nish. Too great an

angle causes concentrated pressure on small areas

which may gouge or burn work surface.

Wire

Wheel

Brush

Fig. 8

Guard

Fig. 7

Wire Cup Brush

WARNING Everyone in the area must

wear protective clothing and safety

goggles or face shields. Fatigued wires and

residue will ﬂ y off the brush with considerable

force, causing potential for serious injury.

WARNING Never exceed Maximum

Safe Operating Speed of brush. Do not

use a damaged brush or one that is func-

tioning improperly (throwing wires, out-of-

balance, etc.). These conditions increase

the possibility of further brush failure and

possible injury. Discard and replace damaged

brushes immediately.

USING WIRE BRUSHES

Wire brushes are useful for removing rust, scale,

burrs, weld slag, etc.

Always install wire cup brushes according to the

accessory manufacterer’s instructions.

Test wheel for balance and loose or damaged wires

by letting it spin for one minute before applying it

to the workpiece. During this time, no one should

stand in front of or in line with it.

Control pressure and surface contact between

wheel and workpiece. Too much pressure causes

over-bending of wires and heat build-up causing

premature wire breaking, rapid dulling and reduced

brush life. Instead of more pressure, try a wire wheel

with more aggressive cutting action (increased wire

size, decreased wire length or different brush type

(knot type vs.crimped wire type).

When using a wire wheel brush, install guard ac-

cording to "Installing/Removing Accessories".

WARNING Because the wires on wire

wheel brushes are directed towards the

operator, a guard must be used to protect the

operator when fatigued wires break.

Aluminum Oxide

For fast cutting, general purpose discs for most

metal jobs. Best for cold-rolled steel, stainless

steel or metals requiring tough, fast cutting, long

lasting abrasives.

Aluminum Zirconia Bi-Cut

Unique grit pattern is arranged in clusters for fast-

er stock removal and cleaning. Ideal for removing

paint from cars, boats, etc. without clogging.

Ceramic

Lasts up to 3 times longer than Aluminum Ox-

ide Discs. For general metal working. Ideal for

tough jobs.

Sanding Disc Selection

Use sanding discs and accessories that are:

• correct size as written on tool’s nameplate.

• rated at or above the RPM listed on the tool’s

nameplate.

• correct accessory, wheel type and grit for the job.

Refer to the table below to select the correct type

of sanding disc for your job. Generally, use 24 or

36 grit for heavy stock removal; 50, 60, or 80 grit

for medium stock removal and 120 grit for ﬁ nishing.

Always begin with a coarse grit, using successively

ﬁ ner grits to obtain the desired ﬁ nish. See your

MILWAUKEE Electric Tool Catalog for a complete

list of sanding discs.

USING SANDING DISCS

Installing Backing Pad and Sanding Discs

1. Remove the battery pack.

2. Wipe the accessories, disc nut and spindle to

remove dust and debris. Inspect the parts for

damage. Replace if needed.

3. Slip backing pad onto spindle with ﬂ at side away

from gear case.

4. Place sanding disc on backing pad and secure

assembly to spindle with disc nut.

Fig. 9

Spindle

Backing

pad

Disc nut

Sanding

disc

5. To tighten, press the spindle lock button while

turning disc nut clockwise with the spanner

wrench provided.

6. To remove backing pad and sanding disc,

remove the battery pack and reverse the pro-

cedure.

Sanding

Hold tool at 5° to 15° angle to ensure proper sand-

ing pressure and control. Too great an angle will

result in too much pressure and could cause exces-

sive wear to the disc and workpiece. Too small an

angle will reduce control.

Use long, sweeping, side to side strokes, advancing

forward to produce the desired ﬁ nish.

Cross Sanding

When ﬁ nishing a surface that has been prepared

by a coarse disc or wheel, sand at right angles

to the strokes made by the coarser disc. Finish-

ing marks left from previous sanding are easily

seen and removed for a uniform ﬁ nish. Failure to

cross sand when changing from a coarse disc to

a ﬁ nishing disc may result in deep scratches and

circular marks.

Removing Welds or Hammer Marks

When removing welds or hammer marks, limit

coarse sanding to the immediate area. Use suc-

cessively ﬁ ner grits to smooth surface.

Finishing Metal

Constantly move across the surface. Work faster on

curved surfaces where contact areas are smaller

and pressure is greater. Flat areas may appear at

the end of the stroke when pressure is too heavy.

Ease up on pressure at end of each stroke and

when reversing strokes.

Troubleshooting

Deep scratches and circular marks can result

from:

• Using too coarse a grit

• Using a partially glazed disc

• Dirt or loose metal on the workpiece

• Failure to sand across the grain when changing

from coarse to ﬁ nishing discs

• Failure to use closed coated discs to reduce the

problem of grains working loose and scratching

the workpiece

Bluish discoloration of metal surface indicates:

• Excessive heat caused by circular motion in a

small area

• Excessive pressure

• Use of worn out or glazed discs

Fig. 10

For best result use only this portion of disc

Hold at a

5° to 15°

angle