Does Solid Carbide Drills on Inclined Surfaces causes headache to you ?

If Solid Carbide Drills usage on Inclined / Curved surfaces causes headache to you or a lot of Drill Breakage issues then read below....

By Abhinav Duggal March 1, 2020

How to correctly use Solid Carbide Drills on Inclined Surfaces ?


When your Carbide Drill's are encountered with Inclined Surface at the Work-piece ENTRY ? What you should do>

  • If Entry Angle = 1° To 5° ---> Reduce your Feed Rate to 1/3 i.e. to 33%
  • If Entry Angle = 5° To 10° ---> Reduce your Feed Rate to 1/4 to 1/3 i.e 25~33%
  • If Entry Angle greater than 10° ---> Caution: Never put our C3HS Or CTHS Carbide Drills directly instead first Mill a Flat Surface on the curved area with a 322 Series Flat End Mill and then with Drills Recommended parameters do the drilling with either C3HS-High Performance Carbide Drills Or CTHS Coolant Fed Drills


However even after reducing the Feed Rates as mentioned above if you still face issues, further suggestions from our engineering team's 100+ years of collective experience can help you further solve your breakage / slippage issues on your Solid carbide drilling. We recommend you,
  • Perform Centring Operation with a Short Carbide Spotting Drills first which should have a same Or Greater Point Angle so that your Solid Carbide Drills point angle is seated properly . So Always follow this rule that Spotting Drills Point Angle >= Carbide Drills Point Angle.
  • Centring operation prevents deflection and extends the Tool life , also prevents drill breakage due to slippage and deflection which is common cause during

When your Carbide Drill's are encountered with Inclined Surface at the Work-piece EXIT ?

  • If Exit Surface is Angled but less than 10° ---> Always reduce DRILLS RECOMMENDED FEED RATE to at least 1/3 (33%) and as much as 1/4 (25%) of the normal recommended Feed rate depending upon EXIT angle. More the EXIT ANGLE more reduction in the FEED.
Caution: Extremely Steep Angles may still cause chipping on the Solid Carbide Drill's Lips or outside corners; So we recommend you go for Our Double Margin Carbide Drills (Flute Diameter 4mm to 16mm) you can drop in message here



Finally some important things for Machinist's to follow for Better Machining Experience & Tooling Cost Reduction >>


If you like our Blog do share the same on other social media & spread word, we are here to help the manufacturing to reduce costs. Kindly leave a comment below. If you have any suggestions or issues pertaining to other machining applications you can leave a comment below and we will try to solve your issues.

You can also have a look at the other blogs Best ways to use Carbide Drills for maximum results.

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.
1 comment
victor vanniel
victor vanniel
September 3, 2020
Good idea to give tips on the finer points of drilling and machining. It prevents the company getting a bad reputation and assures satisfied customers. I learned from it and Also tips from you tube from Haas computerised machinery maker. Better English: I am a no (N) Mechanical Eng.... only before vowels, such as :e,a o,u.,not consonants. Also: We are a manufacturer of etc...... Or: We are a leading, outstanding, manufacturer of.....
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