Are all center drills the same? Frustrated here...

[compact8]

Interesting. Just found that all the drill bits I purchased recently from a vendor are split-point type. Will try to use them without spotting drills and see how the accuracy is like ......

 

[Jimsehr]

Interesting. Just found that all the drill bits I purchased recently from a vendor are split-point type. Will try to use them without spotting drills and see how the accuracy is like ......

I think you should still start a hole with a spotting drill. Because they are short and stiff they don’t want to walk when they start drilling.
Jimsehr

 

[compact8]

I think you should still start a hole with a spotting drill. Because they are short and stiff they don’t want to walk when they start drilling.
Jimsehr

Sure. I just want to test it but just found that it's no longer needed because someone has already done it :

Now I got a new problem with these 135 degree drills in hand - I don't have any suitable spotting drills for them because the angle of the spotting drill must be bigger than 135, say 140 but they are very expensive. I will make sure that the drills I buy in the future will be 118 degrees, not 135.

 

[woodchucker]

Sure. I just want to test it but just found that it's no longer needed because someone has already done it :

Now I got a new problem with these 135 degree drills in hand - I don't have any suitable spotting drills for them because the angle of the spotting drill must be bigger than 135, say 140 but they are very expensive. I will make sure that the drills I buy in the future will be 118 degrees, not 135.

You only need one spotting drill.

 

[compact8]

You only need one spotting drill.

Yes I realized it now because all it needs is just one tiny dent to accomodate the chisel point of the drill bit but I keep wondering why they make spotting drills of different sizes. I have got three in my tool box : 6 mm, 3 mm , 1.5 mm. The latter two will probably sit there to collect dust.

 

[woodchucker]

Yes I realized it now because all it needs is just one tiny dent to accomodate the chisel point of the drill bit but I keep wondering why they make spotting drills of different sizes. I have got three in my tool box : 6 mm, 3 mm , 1.5 mm. The latter two will probably sit there to collect dust.

I don't know.. to make more money?

 

[Jimsehr]

Sure. I just want to test it but just found that it's no longer needed because someone has already done it :

Now I got a new problem with these 135 degree drills in hand - I don't have any suitable spotting drills for them because the angle of the spotting drill must be bigger than 135, say 140 but they are very expensive. I will make sure that the drills I buy in the future will be 118 degrees, not 135.

Just grind spotting drill to degree you want.
Jimsehr