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Tap: Tapping Speeds, Feeds & Lubricants:
FEED, SPEEDS & LUBRICANTS (guidelines/recommendations shown below):
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Speeds for machine tapping using HSS taps
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MATERIAL
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FEED SPEED (SFM)
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LUBRICANT
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Aluminium
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70-90
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Soluble oil
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Aluminium alloy
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50-70
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Soluble, light base or lard oil
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Brass
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60-100
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Light base oil
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Bronze
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30-40
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Light base oil
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Copper
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60-80
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Light base oil
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Gun metal
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50-60
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Soluble, light base or lard oil
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Grey cast iron
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30-60
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Dry or soluble oil
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Alloy cast iron
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15-30
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Sulphur based oil
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Malleable iron
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20-40
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Soluble or sulphur based oil
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Magnesium alloy
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50-70
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Soluble oil or parafin with lard oil
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Nimonic alloy
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10-12
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Very high pressure cutting oil
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Plastics
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50-70
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Dry, freeze spray, liquid soap
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Mild steel
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30-50
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Sulphur based oil
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Carbon steel to 4%
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20-40
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Sulphur based oil
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Carbon steel to 7%
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20-30
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Sulphur based oil
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Carbon steel to 7%+
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15-25
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Sulphur based oil
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Steel alloys to 60T
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15-25
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Sulphur based oil
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Steel alloys to 60T+
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10-15
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Sulphur based oil
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Stainless steels
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10-20
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Sulphur based oil
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Tool steels
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15-25
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Sulphur based oil
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There are many variables that can affect tapping speeds - experiment to find the ideal.
A good rule is to start at a slow speed and work up to a faster speed
Tapping speeds (RPM=Revs per minute) can be calculated:-
RPM = Feed speed (SFM) divide by 0.26 x tap OD(outside dia)
Tapping speeds are determined by many factors, main ones being:
a) thread pitch
b) material being tapped
c) depth of thread
d) hole depth
e) hole type: ‘through’ or ‘blind’
f) lubricant quality and flow rate
Tapping speeds should be decreased if:-
a) ‘bottom’ lead is used or ‘spiral-flute’ taps are used
b) lubricant is poor, or flow is restricted
c) thread depth percent increases
d) thread pitch is coarse
e) if cutting ‘taper-threads’ (50 percent normal speed)
f) if cutting ‘Acme’ or ‘Trapezoidal’ threads (40 percent normal speed)
Tapping speeds can be increased if:-
a) thread depth decreases
b) thread pitch is fine
c) coolant flow and quality is good
d) spiral-point taps are used
- On our website there is a lot of other very useful ‘Technical’ Data & Information for you to view
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PRINT any Technical Data page you are viewing - [To help you do this, go to: File menu (click on it), click on Page Setup (in dropdown menu) - set Margins at 6mm for Left, Top, Right, Bottom - click OK. -Go back to: File menu (click on it)- click on Print - type Number of Copies required - click on Print. It will now print the information
©=copyright - ‘Technical Data’ shown in our site can be freely used. This information must NOT
be reproduced or published in any article or website, without the written permission of:
The Tap & Die Co, London
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