In the actual production, **PURROS Machinery** has collected mass customers’ problems about grinding drill bits by hand (**manual grinding drill bits**), now, list the summary of the problems and how to solve as bellow for your reference and study. In the actual production, PURROS Machinery has collected mass customers’ problems about grinding drill bits by hand (manual grinding drill bits), now, list the summary of the problems and how to solve as bellow for your reference and study.

If you have the same troubles in drill machining please refer to the five points as follow, hope this solutions of technical drilling problems are useful to you.

- The diameter of drilling is bigger than on the drawingReason: Two lengths of major cutting lips (major cutting edges) are different, and the height is yet.
- There is a special phenomenon that the drill bit doesn’t work during machining.Reason: The cutting lip is dull (not sharp) and lip relief angle (Lip Clearance Angle) of drill bit is too big.
- The hole after drilling is deflected.Reason: The chisel edge is too long leads to the unstable centering.
- The drilled hole is multilateral.Reason: The lip relief angle (Lip Clearance Angle) of drill bit is too big, and two lengths of major cutting lips are different.
- Special Phenomenon that displays “breaking edge”Reason: The sharpened drill cutting lip is too sharp that leads to point angle to small.
- The drill bit grinding by hand that depends on very experienced mechanic to eyeball the good or bad of drill bit while grinding drill bit, and adjustment temporary. So the experience of mechanic decides to the quality of drill bit. PURROS machinery has the full automatic drill bit grinding machines; it’s good to solve the above problems, it doesn’t require an operator to be very experienced, and just take a few minutes to learn grinding instructions. And also the drill bit grinder adopts a portable design, equipped with many kinds of collects that are suited for many different diameters of drill bits. More information can be found on our website: http://www.drillbitgrinder.com

Hi, PURROS

A question: When two holes expansion, there are Non-symmetric after drilling. Running out of drill when attached to the machine, Loose holder.

Thank you in advance!

Hi, PURROS

A question: When two holes expansion, there are Non-symmetric after drilling. Running out of drill when attached to the machine, Loose holder.

Thank you in advance!

Hi, PURROS

A question: When two holes expansion, there are Non-symmetric after drilling. Running out of drill when attached to the machine, Loose holder.

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

Thank you in advance!

First, Regrind correctly.

So please kindly check holder or select another one to try.

And check run out after fixing to the chuck.

You’re welcome ☺