Rohit Cutting Tools - Best way to use High Performance Carbide Drills !

July 26, 2016

Use of High Performance Carbide Drills is increasing everyday; to best use Carbide Drills, knowledge of industry best practices is MUST !

Problem with High Performance Carbide Drills usage today !

With everyday rising demand of higher productivity and low cost Auto components; High Performance Solid Carbide Drills are becoming the need of the hour however in this endeavour Industries are facing the problem as to what are the best ways to use Carbide Drills. Many CNC shop floors still face a lot of breakage issues, low performance issues due to wrong usages of there Carbide Drills.


We have list down below the best practices used by experienced machinist around the globe so that their High Performance Carbide Drills { C3HS Series Drills or CTHS Coolant Fed Drills Series } yield the best possible results.

´╗┐Best Practices for your Carbide Drills

  1. The first on my list is Machining Centre (VMC) itself, in High Performance Drilling the Machining Centre is the most important part. Check the machining centres are of best quality with Strong Rigidity, Least Spindle Run-out, Strong Coolant Pressure. Machines are like humans if you pamper them they will give you the best results in your relationships; so do not forget to pamper your machines with the best coolant, regular maintenance checks & also best environment. Over my 8+ years of Application experience, I visited over 200+ CNC shops, but this one I visited in the 40* North Indian Summer which had Fully Air Conditioned setup, with dust free environment; I felt that I am visiting a conference room of 5* Star property instead of a CNC shop floor; hence the machinist of the shop-floor were able to get maximum out of their machines & tools because of the environment they were put in. 
  2. Holding system will come 2nd most important parameter on my list as this plays important role in reducing the TIR or commonly known as Tip Indicative run-out and also important for better gripping. So always use Hydraulic or Shrink Fit holding systems for best results.
  3. Clamping Fixture should always be hydraulic , avoid the use of manual fixtures with tightening screws/bolts as it may cause the failure of high performance tooling and will also lower your productivity considerably as you may encounter noises & poor finish due to the poor fixtures. 
  4. Importance of TIR  Studies show that for every increase in TIR by 0.010mm i.e. 10 Microns increase in TIR results in reduction in life by 10% and this factor is not linear but exponential in nature. It means that if High Performance Carbide Drills cost you say $100 it will give you result of $90 and will decrease substantially to even lower than say $50 with increase in run-out to 50-microns TIR. Hence we conclude to get best results of your High Performance Cutting Tools ; make sure your TIR < 10 microns and always do maintenance of your machine Spindle. 
  5. Coolant & its pressure Studies shows that a good quality coolant can increase the life of the tool by at least 60%. Hence using quality coolant with right mix & right pressure is a must. For checking the right coolant mix you can use Refractometer (How to use refractormeter)
  6. Most Importantly Selecting the RIGHT Carbide Drills 
a) Always select the lowest possible flute length Carbide Drill for best rigidity and better life. Do not go for long flute lengths Carbide Drills in order to get maximum regrinding (you know what I mean, every machinist in his/her endeavor to reduce tooling cost invariably tries to use higher flute lengths & finally screws it up....) As it leads to premature breakage of Carbide Drill and hence your tooling cost goes up considerably; leaving you to close your projects due to over expenditure on the tooling or other stringent actions from your management.

b) Shorter flute length will also mean that you can have higher parameters, better Drill life; study shows that reducing the L/D ratio from 8 to 4 leads to more than 3 Times the life improvement & close to Double feed rates can be used.

c) Select drill as per the material to machine. So if you want to machine Alloy Steel Or Stainless Steel then you can go for our C3HS Series Drills or CTHS Coolant Fed Drills Series respectively with shortest possible flute lengths.

d) Keep the overhang to least possible to prevent premature failures of the Carbide Drills

You can also have a look at the other blogs How to use Solid Carbide Drills on Inclined or Curved Surfaces if this problem is also common for you.

Abhinav Duggal
Abhinav Duggal

I am an Mechanical Engineer from Delhi College of Engineering and have been suggesting customers in field of Carbide & HSS cutting tools since 2005 to reduce their tooling cost & increase productivity; so far I have helped more than 300+ clients to reduce their tooling costs.

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