Inexpensive drill bit set on sale.

[architect]

Reviving an old thread because I'm doing some purchase research. Any problem using 135 for "general purpose" as I understand they are typically for harder materials. Do people carry both 135 and 118 or just have one and call it a day? Thanks.

 

[Chip Maker]

I would say 118 is the norm for my trade. Seems a moot point since I'm constantly sharpening them. You can put on any angle you want.

 

[PeterT]

Another consideration is 120-deg center drills are a lot more common to find to use for 118-deg drills. The 135-deg drill would ideally require that angle or larger & these CD's are less common & generally more expensive. I know a lot of people just drill centerless & call it good & some of the 135 are stub length which helps with rigidity and/or have tip geometry that helps. But 118-deg is also my go to.

 

[Tom Kitta]

I actually never check the angle - I am more concerned with size, sharpness followed by cutting speed (usually quite slower then recommended). I think the 118 vs. 135 is mostly for production where you are trying to squizze every possible gain you can. Once you know material exactly, machine is CNC with known parameters and through try and error you can start getting the most for your drill $.

The only exception is brass - it tends to grab things - but I do that just few times a year.

I guess I would notice if angle is more then 135 or less then 118 - I believe for plastics the angle is very high.

 

[Chip Maker]

I actually never check the angle - I am more concerned with size, sharpness followed by cutting speed (usually quite slower then recommended). I think the 118 vs. 135 is mostly for production where you are trying to squizze every possible gain you can. Once you know material exactly, machine is CNC with known parameters and through try and error you can start getting the most for your drill $.

The only exception is brass - it tends to grab things - but I do that just few times a year.

I guess I would notice if angle is more then 135 or less then 118 - I believe for plastics the angle is very high.

Try putting flats on the cutting lips for brass. The drill won't pull in. You'd notice this if drilling manually.

 

[GummyMonster]

A couple pointers I came across from other sites while researching driills and angle preferences.
- As far as 118 vs 135 degrees on simple thing to note 135's drill easier but don't find
center as well, 118's center easier but drill with more pressure. Get the 118's if you won't
be countersinking most of your holes first.
I've also read that 135 degree bits are preferred by some when drilling a single size, and not starting a pilot hole and increasing in size.
These are not my personal experience, just tips from others hobby machinists.
Hope this helps,
Ken