tool radius compensation

hello everyone, I'm trying to machine a hole with a diameter of 20mm, but linuxcnc is not compensating for the tool's radius, it's machining a hole with a diameter of 26mmI set the tool radius in the Tool table 6mm.tool 12mm.
how to solve it?
thanks 
G17 G21 G40 G90 G94
T1 M6
G54 S5000 M3 F800
G0 Z30
X0 Y0
Z10
G1 Z0
G1 G41 D1 X10
G2 X10 Y0 I-10 J0 Z-5 P5
G1 G40 X0 Y0
G1 G41 X10 
G3 X10 Y0 I-10 J0
G1 G40 X0 Y0
G0Z30
M30
 

Pretty sure the tool table needs diameter, not radius of tool.
Try that and report back as it's been several years that i have not used a mill.
Second result is from the documents, others are from the forum, regarding G41, G42 tool compensation.
www.google.com/search?q=g41+site%3Alinux...sclient=gws-wiz-serp

linuxcnc uses tool radius, I put the tool diameter in the tool table linuxcnc gives the following message "arc movement in a concave corner cannot be achieved by the tool without damaging the material"

From my doku, about cuttercompensation. The machining diameter must be >= 2.25 x tooldiameter. It seems this didn't change in the meantime.
G41G42 LEAD IN '2.25 x ToolDia' minLIMIT
 

Routercnc wrote:

linuxcnc uses tool radius, ....

It does not, it uses diameter, see attached:

I inserted the tool diameter into the tool table and the following message appeared ... "Arch movement in a concave corner cannot be achieved by the tool without damaging the material"