Feed in drilliing
. state the factors that contribute to an efficient feed rate.
Feed is the distance (x) a drill advances into the work in one complete rotation. Feed is expressed in hundredths of a millimeters. Example -0.040mm
The rate of feed is dependent upon a number of factors.
Finish required
Type of drill(drill material)
Material to be drilled
Factors like rigidity of the machine, holding of the workpiece and the drill, will also have to be considered while determining the feed rate. If these are not to the required standard, the feed rate will have to be decreased. It is not possible to suggest a particular feed rate taking all the factors into account.The average feed values suggested by the different manufacturers of drill.
Drill diameter Rate of feed
(mm)H. S. S (mm/rev)
1.0-2.5 0.040-0.060
2.6-4.5 0.050-0.100
4.6-6.0 0.075-0.150
6.1-9.0 0.100-0.200
9.1-12.0 0.150-0.250
12.1-15.1 0.200-0.300
15.1-18.0 0.230-0.330
18.1-21.0 0.260-0.360
21.1-25.0 0.280-0.380
Too coarse a feed may result in damage to the cutting edges or breakage of the drill. Too slow a rate of feed will not bring improvement in surface finish out may cause excessive wear of the tool point, and lead to chattering of the drill.for optimum results in the feed rate while drilliing, it is necessary to ensure the drill cutting edges are sharp.use the correct type of cutting fluid.
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