Round nose or core box

[Joe Scharle]

That is the question!

What's the specific, absolute, unmitigated difference in the two?

Tom?...Charles?

[Alan in Little Washington]

They are both very similar, and similar to the ball nose bit. Many vendors use the term interchangeably but I think there is a slight difference. I also think MLCS has theirs labelled backwards. This is what I learned:

1. Ball nose bit is almost a sphere except where it attaches to the shank. It will do a slight under cut once plunged. Used to cut track section connectors in Brio toys.


2. Round nose- perfect hemisphere tip with cutting edge on the hemisphere only. (MLCS calls this a core box bit)



3. Corebox- perfect hemisphere (or not) but with long straight sides also having cutting edges. Allows you to plunge and move sideways to core out a slightly deeper but still shallow box that has rounded inside bottom corners.



Sounds like I know what I'm talking about, but it is just a guess.

[Joe Scharle]

That's exactly why I posed the question, Alan. There doesn't seem to be any logical reasoning to the naming convention, as you point out. I was searching for a 1/2" radius round nose and all sorts of candidates showed up. I even found a radius bit on 1 page in a catalog, that was the same part number as a round nose on another page, in the same catalog!

[junquecol]

Joe, I posted this earlier, but the cyberspace gods must have eaten it. I have a 1" (1/2" radius) round nose bit you may use if yours is a "one of a kind" project. Saves buying a bit for only one use.

[Joe Scharle]

Thanks Bruce, I may get back to you.

[CarvedTones]

I am shocked to be answering a question about things router from the guy I would mostly like pick as my life line if asked a question about them on that game show, but I did ask this once when ordering a bit. I was told that a core box is a round nose with sides. In other words if the cutting surface is an arc with no flat spot, it is a round nose. If there is a flat spot, it is a core box.

[Joe Scharle]

I am shocked to be answering a question about things router from the guy I would mostly like pick as my life line if asked a question about them on that game show, but I did ask this once when ordering a bit. I was told that a core box is a round nose with sides. In other words if the cutting surface is an arc with no flat spot, it is a round nose. If there is a flat spot, it is a core box.

A very good description, Andy. If only we could get the vendors in compliance!