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Old 4th Jul 2021, 10:27 pm   #20
pmmunro
Octode
 
Join Date: Jul 2004
Location: Dundee, UK.
Posts: 1,797
Default Re: Wolf Electric Tools Ltd

The "No-load" speed of a motor is the speed at which it will run when no load is applied. As soon as a load is applied to a universal motor of the type used in power drills of this period, the speed will fall according to the load applied.

The optimun speed for drilling depends on many factors and tables of "feeds and speeds" are published in engineering guides. In general, the smaller the drill bit, the faster it can be run. This relates to the peripheral speed of the bit. For highest production rates, drill bits need to be run as fast as is practical and this will depend, amongst other things, on lubrication and cooling of the drill bit. The temperature that the drill bit can withstand depends on the material from which it is made.The heating of the material being drilled is also important because some, like certain grades of stainless steel, are subject to work hardening which can make them difficult to cut.

Feeds relate to the rate at which the drillbit is fed into the material and can really only be applied accurately to machine tools although it does have some bearing on hand drilling.

PMM
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