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Parts & Service: 020 8988 7400 / E-mail: Parts@clarkeinternational.com or Service@clarkeinternational.com
GENERAL NOTES ON MILLING
Set up the workpiece in a similar manner to that for drilling.
• Slowly bring the cutter into contact with the work piece and start
machining.
• DO NOT attempt to make too bigger cuts than the cutter and
machine are capable of, it is much better and safer to make several
small passes.
• Always use an appropriate cutting/cooling fluid whilst machining,
which can be applied with a small brush etc, NOT FINGERS.
• DO NOT allow swarf to build up in the cutting area. Stop the
machine and remove using a suitable implement, (brush etc).
• When finished turn the machine OFF, return the cutter to its highest
position and allow it to come to a complete stop before attempting
to remove the work piece or tool.
• Always finish by cleaning and drying the machine, and storing all
tools and accessories etc, safely.
CUTTING SPEEDS
In order to drill, and particularly mill satisfactorily, it is most important that the
correct cutting speed is used,
Cutting speed is the speed at which the cutting edge of the tool passes over
the work. This is usually expressed in feet per minute or metres per minute.
For a given material there will be an optimum cutting speed for a certain set of
machining conditions, and from this speed the spindle speed (RPM) can be
calculated. Factors affecting the calculation of cutting speed are:
• The material being machined (steel, brass, aluminium etc. - see
table below)
• The material the cutter is made from i.e. Carbon steel, High speed
steel (HSS), carbide or ceramics.
Material type Meters per min feet per min
Steel (tool) 15 - 18 50 - 60
Mild steel 30 - 38 100 - 125
Cast iron (medium) 18 - 24 60 - 80
Bronze 24 - 45 80 - 150
Brass (soft) 45 - 60 150 - 200
Aluminium 75 - 105 250 - 350
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