diff --git a/LuaLibs/FaceData.lua b/LuaLibs/FaceData.lua
index e716295..13d9b1c 100644
--- a/LuaLibs/FaceData.lua
+++ b/LuaLibs/FaceData.lua
@@ -138,8 +138,7 @@ function FaceData.GetEdgesInfo( ProcOrId, idFace )
       CurrentEdge.bIsEndOpen = EdgesEgt[nNextEdgeIndex].Open
       CurrentEdge.ptStart = Point3d( EdgesEgt[i].Start)
       CurrentEdge.ptEnd = Point3d( EdgesEgt[nNextEdgeIndex].Start)
-      CurrentEdge.vtEdge = CurrentEdge.ptEnd - CurrentEdge.ptStart
-      CurrentEdge.vtEdge:normalize()
+      CurrentEdge.vtEdge = CurrentEdge.ptEnd - CurrentEdge.ptStart ; CurrentEdge.vtEdge:normalize()
       CurrentEdge.sType = 'Standard'
       CurrentEdge.id = i - 1
 
diff --git a/LuaLibs/LeadInOutLib.lua b/LuaLibs/LeadInOutLib.lua
index cb8f14e..93cf9f7 100644
--- a/LuaLibs/LeadInOutLib.lua
+++ b/LuaLibs/LeadInOutLib.lua
@@ -7,9 +7,38 @@ local LeadInOutLib = {}
 -- Include
 require( 'EgtBase')
 local BeamData = require( 'BeamDataNew')
+local FaceData = require( 'FaceData')
 
 EgtOutLog( ' LeadInOutLib started', 1)
 
+-------------------------------------------------------------------------------------------------------------
+local function GetExtraAddLengthInclinedSides( Face, Edge)
+
+   -- se faccia rettangolare i lati sono tutti a 90deg, inutile fare conti
+   if FaceData.IsFaceRectangle( Face) then
+      return 0, 0
+   end
+
+   local nPreviousEdgeIndex = Edge.id + 1 - 1
+   if nPreviousEdgeIndex < 1 then
+      nPreviousEdgeIndex = #Face.Edges
+   end
+   local nNextEdgeIndex = Edge.id + 1 + 1
+   if nNextEdgeIndex > #Face.Edges then
+      nNextEdgeIndex = 1
+   end
+
+   local vtEdgePrevious = Face.Edges[nPreviousEdgeIndex].vtEdge
+   local vtEdgeNext = Face.Edges[nNextEdgeIndex].vtEdge
+   local dLengthEdgePrevious = Face.Edges[nPreviousEdgeIndex].dLength
+   local dLengthEdgeNext = Face.Edges[nNextEdgeIndex].dLength
+
+   local dExtraPrevious = dLengthEdgePrevious * ( Edge.vtEdge * -vtEdgePrevious)
+   local dExtraNext = dLengthEdgeNext * ( -Edge.vtEdge * vtEdgeNext)
+
+   return dExtraPrevious, dExtraNext
+end
+
 -------------------------------------------------------------------------------------------------------------
 local function GetPerpendicularLeadInOutDirection( Face, Edge)
 
@@ -83,8 +112,9 @@ function LeadInOutLib.CalculateLeadInOut( sLeadInOutType, Parameters)
    local bIsStartClosed = not Edge.bIsStartOpen
    local bIsEndClosed = not Edge.bIsEndOpen
 
-   -- accorciamento per lati chiusi (è sempre l'impronta utensile)
+   -- accorciamento per lati chiusi
    LeadInOut.dToolMarkLength = sqrt( dDepthToMachine * Tool.dDiameter - dDepthToMachine * dDepthToMachine)
+   LeadInOut.dExtraAddLengthStart, LeadInOut.dExtraAddLengthEnd = GetExtraAddLengthInclinedSides( Face, Edge)
    -- allungamento per faccia singola (aperta in tutte le direzioni)
    LeadInOut.dAddedLengthOpenFace = BeamData.CUT_EXTRA
 
@@ -105,14 +135,14 @@ function LeadInOutLib.CalculateLeadInOut( sLeadInOutType, Parameters)
 
    -- calcolo allungamenti / accorciamenti
    if bIsStartClosed and bIsEndClosed then
-      LeadIn.dStartAddLength = -LeadInOut.dToolMarkLength
-      LeadOut.dEndAddLength = -LeadInOut.dToolMarkLength
+      LeadIn.dStartAddLength = -LeadInOut.dToolMarkLength - LeadInOut.dExtraAddLengthStart
+      LeadOut.dEndAddLength = -LeadInOut.dToolMarkLength - LeadInOut.dExtraAddLengthEnd
    elseif bIsStartClosed then
-      LeadIn.dStartAddLength = -LeadInOut.dToolMarkLength
+      LeadIn.dStartAddLength = -LeadInOut.dToolMarkLength - LeadInOut.dExtraAddLengthStart
       -- eventuale correzione per accorciamento maggiore di larghezza tasca
       LeadOut.dEndAddLength = max( -LeadIn.dStartAddLength - Edge.dLength + 10 * BeamData.CUT_EXTRA, BeamData.CUT_EXTRA)
    elseif bIsEndClosed then
-      LeadOut.dEndAddLength = -LeadInOut.dToolMarkLength
+      LeadOut.dEndAddLength = -LeadInOut.dToolMarkLength - LeadInOut.dExtraAddLengthEnd
       -- eventuale correzione per accorciamento maggiore di larghezza tasca
       LeadIn.dStartAddLength = max( -LeadOut.dEndAddLength - Edge.dLength + 10 * BeamData.CUT_EXTRA, BeamData.CUT_EXTRA)
    else