Choosing Speeds - Grizzly G7945 Owner's Manual

Using the Drill Bit Speed Chart
The chart shown in Figure 20 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.
T w i s t / B r a d P o i n t D r i l l B i t s
1/16" – 3/16"
13/64" – 3/8"
25/64" – 5/8"
11/16" – 1"
S p a d e / F o r s t n e r B i t s
1/4" – 1/2"
9/16" – 1"
1-1/8" – 1-7/8"
2–3"
H o l e S a w s
1/2" – 7/8"
1" – 1-7/8"
2" – 2-7/8"
3" – 3-7/8"
4" – 5"
R o s e t t e C u t t e r s
Carbide Insert Type
One-Piece Type
T e n o n / P l u g C u t t e r s
3/8" – 1/2"
5/8" – 1"
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Choosing Speeds

S o f t W o o d H a r d W o o d
3000 2500
2000 1500
1500 750
750 500
S o f t W o o d H a r d W o o d
2000 1500
1500 1250
1000 750
500 350
S o f t W o o d H a r d W o o d
500 500
400 400
300 300
200 200
100 100
S o f t W o o d
H a r d W o o d
350 250
1800 500
S o f t W o o d
H a r d W o o d
1200 1000
800 600
Figure 20. Drill bit speed chart.
Lubrication Suggestions
Wood/Cast Iron ...........................................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.
P l a s t i c B r a s s A l u m i n u m
2500 2500
2000 1250
1500 750
1000 400
P l a s t i c B r a s s A l u m i n u m
P l a s t i c B r a s s A l u m i n u m
600 600
500 500
400 400
300 300
200 200
P l a s t i c B r a s s A l u m i n u m
P l a s t i c B r a s s A l u m i n u m
G7945/G7946 Radial Drill Press
M i l d S t e e l
3000 2500
2500 1250
1500 600
1000 350
M i l d S t e e l
M i l d S t e e l
600 500
500 400
400 300
300 200
200 100
M i l d S t e e l
M i l d S t e e l