Choosing Speeds - Grizzly G7944 Owner's Manual

Using the Drill Bit Speed Chart
The chart shown in Figure 27 is intended as
a guide only. Always follow the manufacturer's
speed recommendations if provided with your
drill bits, cutters, or hole saws. Exceeding the
recommended speeds may be dangerous to the
operator.
The speeds shown here are intended to get you
started. The optimum speed will always depend
on various factors, including tool diameter, drilling
pressure, material hardness, material quality, and
desired finish.
Often, when drilling materials other than wood,
some type of lubrication is necessary.
Twist/Brad Point Drill Bits
1/16" – 3/16"
13/64" – 3/8"
25/64" – 5/8"
11/16" – 1"
Spade/Forstner Bits
1/4" – 1/2"
9/16" – 1"
1-1/8" – 1-7/8"
2–3"
Hole Saws
1/2" – 7/8"
1" – 1-7/8"
2" – 2-7/8"
3" – 3-7/8"
4" – 5"
Rosette Cutters
Carbide Insert Type
One-Piece Type
Tenon/Plug Cutters
3/8" – 1/2"
5/8" – 1"
Model G7943/G7944 (Mfd. Since 09/17)

Choosing Speeds

Soft Wood Hard Wood
3000 2500
2000 1500
1500 750
750 500
Soft Wood Hard Wood
2000 1500
1500 1250
1000 750
500 350
Soft Wood Hard Wood
500 500
400 400
300 300
200 200
100 100
Soft Wood Hard Wood
350 250
1800 500
Soft Wood Hard Wood
1200 1000
800 600
Figure 27. Drill bit speed chart.
Lubrication Suggestions
Wood ...........................................................None
Plastics ............................................Soapy Water
Brass ...............................Water-Based Lubricant
Aluminum ..................... Paraffin-Based Lubricant
Mild Steel ............................. Oil-Based Lubricant
Larger bits turning at slower speeds tend
to grab the workpiece aggressively. This
can result in the operator's hand being
pulled into the bit or the workpiece being
thrown with great force. Always clamp the
workpiece to the table to prevent injuries.
Plastic Brass Aluminum
2500 2500
2000 1250
1500 750
1000 400
Plastic Brass Aluminum
Plastic Brass Aluminum
600 600
500 500
400 400
300 300
200 200
Plastic Brass Aluminum
Plastic Brass Aluminum
Mild Steel
3000 2500
2500 1250
1500 600
1000 350
Mild Steel
Mild Steel
600 500
500 400
400 300
300 200
200 100
Mild Steel
Mild Steel
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