Replies

1. 
   forestgirl | Apr 21, 2005 08:22pm | #1

   Most catalogs provide pics to illustrate the different measurements.  For a roundover bit, I'd think using diameter would make the most sense.  MLCS has a very clear drawing for their bull nose bits (click here).

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
   Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

1. 
   gpasewicz | Apr 21, 2005 10:19pm | #4

   You're right.  I've been looking at the MLCS and it's explained pretty well.

2. 
   jackplane | Apr 21, 2005 09:28pm | #2

   Diameter, but a bullnose is not a true circle. The radius on the top edge is larger than the bottom edge.

   
   

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   Edited 4/21/2005 2:34 pm ET by jackplane

3. 
   BrentS | Apr 21, 2005 09:45pm | #3

   As you say,different manufacturers use different systems.Take LV for instance.They have bullnose bits that are half radius and bits that are full radius.This means that on a 3/4 inch board the full radius curve will start 3/8 inch from the edge and the half radius will start 15/32 inch from the edge.

    http://www.leevalley.com/wood/page.aspx?c=2&p=46182&cat=1,46168

       Check out the LV site,they make everything very clear.

                                                                            Brent

1. 
   gpasewicz | Apr 21, 2005 10:25pm | #5

   I've been looking at LV in addition to the MLCS bits.

   Some sites show the diameter as being the diameter of the entire bit (diameter of 1 1/2", for example), without indicating the diameter of the cut.  Or, what's worse, they'll show a diagram with labels for various dimensions, (r = radius, e.g.) but not give measurements.

   I call for universal router bit labeling standards!  ;-)

   Thanks.

4. 
   Routerman | Apr 22, 2005 12:57am | #6

   Radius of circle for that cutter, which is 1/2 circle,  = 3/8". But, in my view that would be cutting it a little close on 3/4 stock. Sample in picture link is 1/2 of 1" diameter circle on a 3/4" stick, a softer feel and look. (Note, the fence is offset for this full thickness cut.)

   Routers

1. 
   WillGeorge | Apr 22, 2005 08:19pm | #7

   I go with Routerman explanation..

   Diameter of the bit to me means the outside diameter of the entire bit.