diff --git a/Strategies/Standard/STR0010/STR0010.lua b/Strategies/Standard/STR0010/STR0010.lua
index b493acc..5a30ae0 100644
--- a/Strategies/Standard/STR0010/STR0010.lua
+++ b/Strategies/Standard/STR0010/STR0010.lua
@@ -216,8 +216,9 @@ function STR0010.Make( bAddMachining, Proc, Part, CustomParameters)
 
    -- si lavora seconda BottomFace
    if Proc.Topology.sFamily == 'DoubleBevel' or Proc.Topology.sName == 'Rabbet-2-Through' then
-      -- se maggiore di angolo retto
-      if Proc.AdjacencyMatrix[1][2] < 10 * GEO.EPS_SMALL then
+      local dAngleBetweenFaces = Proc.AdjacencyMatrix[1][2]
+      -- se convesso o concavo maggiore di angolo retto
+      if dAngleBetweenFaces >= -91 then
          Milling = {}
          OptionalParametersFaceByMill = { nStepType = MCH_MILL_ST.ONEWAY, bIsSplitFeature = bIsSplitFeature, dExtendAfterTail = dExtendAfterTail}
          EdgeToMachine = GetBottomFaceEdge( Proc, 2)