15
CUTTING SPEEDS
Factors which determine the best speed to use in any drill press operation are:
1.
Kind of material being worked.
2.
Size of hole.
3.
Type of drill.
4.
Quality of cut desired.
Generally, the smaller the drill, the greater the required RPM. In soft material, the
speed should be higher than for hard metals.
As a guide, the drill speed for a given drill bit size, is according to the table below.
Wood
2740
1410 -
2270
970 -1280
480 - 580
250 - 400
180
Speed Range
(RPM)
in
3/8
1/2
-
-
-
-
mm
9.5
12.5
-
-
-
-
Zinc
in
1/4
3/8
1/2
-
-
-
Diecast
mm
6.4
9.5
12.5
-
-
-
Alum &
in
7/32
11/32
15/32
-
-
-
Brass
mm
5.6
8.75
12
-
-
-
in
3/16
5/16
7/16
-
-
-
mm
4.8
7.9
11
-
-
-
Cast Iron
in
1/8
1/4
11/32
1/2
-
-
& Bronze
mm
3.2
6.4
8.75
12.5
-
-
Mild Steel
in
3/32
5/32
1/4
3/8
1/2
-
& Malleable
mm
2.4
4
6.4
9.5
12.5
-
Cast Steel
in
1/16
1/8
3/16
5/16
7/16
1/2
& Med Carbon mm
1.6
3.2
4.8
7.9
11
12.5
Stainless
in
3/64
1/16
1/8
1/4
3/8
1/2
and Tool Steel
mm
1.2
1.6
3.2
6.4
9.5
12.5
Plastic
Содержание Metalworker CDP301B
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Страница 18: ...18 HEAD ASSEMBLY ...
