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Coolant Knob Configurations

Coolant knobs are come in various designs.  Many machine companies have developed their own standards to fit their spindle design.  Unfortunately there is no way of determining which design each machine is using without detailed information for that retention knob. 
The image to the right (see PDF below) shows the common configurations in the market today.  Your knob could be "A" or it could be "A+D+F".  Many machine companies change the knob per how the machine was ordered.  Standard coolant system may be "A" but a high pressure system may be "F".

Common misunderstandings
  • My knob is a P40T-I or P40 Type I
    All of the knobs shown in the image are P40 Type I.  
    P40 = the thread size or taper size (40 = 40 taper) 
    Type I = the pull angle ( I = 45, II = 60, III = 90)
  • My knob is a MAS403
    All of the knobs shown in the image are MAS403.  MAS403 is a basic standard for non-coolant knobs.
  • Quote the standard MAS403 or P40T Coolant Knob
    There is no standard coolant knob for this configuration.  No standard has been written, this is a machine specific design, the standard is non-coolant.  The standard coolant knob for many machines from Japan, Korea and Taiwan is JIS B6339 which is a 75 degree knob which is not interchangeable.  Due to no standard, all MAS403 or P40T coolant knobs are machine company designed.
  • My knob is the same as standard but with a hole in it...
    Are you sure?  If the wrong seal is applied coolant can leak into machine bearings and cause serious damage to the machine spindle.  If the spindle requires a ID pilot, a knob with a hole can cause damage to that pilot costing thousands to replace.
  • Here is the machine model number...
    Unfortunately machine model number is like saying Ford F150, it does not tell us what motor was ordered, how it was configured or what options were supplied.  There is no database share to the public, the only people that have access to how your machine was configured is the customer and the machine dealer.  
Receive the correct item the first time
The only way to guarantee the correct knob is to supply the drawing from the machine manual.  All machine manuals have a drawing of the knob for that machine configuration.  Please note that if you ordered a special configuration you must request the correct drawing.

Don't void your machine warranty on a guess
Using the wrong knob can cause serious damage and void the machine warranty, in many cases to save a couple of dollars.  Consider spindle speeds up to 33,000 RPM's, shopping for the lowest cost knob can be dangerous and unsafe.  Use manufacturer's who follow the machine builders specifications.

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  764k v. 1 May 18, 2015, 7:54 AM Lee Flick