diff --git a/LuaLibs/MachiningLib.lua b/LuaLibs/MachiningLib.lua
index f013fe2..ed176f6 100644
--- a/LuaLibs/MachiningLib.lua
+++ b/LuaLibs/MachiningLib.lua
@@ -356,16 +356,16 @@ local function FindMachining( MachiningType, sType, Params, bTopHead, bDownHead,
    end
    if ( BEAM and BEAM.BW) or MachineHeadType == ONE_HEAD or MachineHeadType == TWO_EQUAL_HEADS or ( MachineHeadType == TWO_UP_DOWN_HEADS and not bDownHead) then
       _, sType = EgtEndsWith( sType, '_H2')
-   elseif ( not BEAM or not BEAM.BW) and MachineHeadType == TWO_UP_DOWN_HEADS and bDownHead then
+   elseif not ( BEAM and BEAM.BW) and MachineHeadType == TWO_UP_DOWN_HEADS and bDownHead then
       if not EgtEndsWith( sType, '_H2') then
          sType = sType .. '_H2'
       end
    end
    local MachineHeadUse = MachineHeadType
-   if not BEAM or not BEAM.BW then
+   if not ( BEAM and BEAM.BW) and MachineHeadUse == TWO_EQUAL_HEADS then
       MachineHeadUse = ONE_HEAD
    end
-   if BEAM and BEAM.BW and MachineHeadUse == TWO_UP_DOWN_HEADS and bTopHead and bDownHead then
+   if MachineHeadUse == TWO_UP_DOWN_HEADS and bTopHead and bDownHead then
       -- se posso usare entrambe le teste, la gestisco come una macchina a due teste da sopra
       MachineHeadUse = TWO_EQUAL_HEADS
    end
@@ -374,7 +374,7 @@ local function FindMachining( MachiningType, sType, Params, bTopHead, bDownHead,
    for i = ForStart, ForEnd, ForStep do
       local Machining = Machinings[i]
       local sMachiningType = Machining.Type
-      if BEAM and BEAM.BW then
+      if ( BEAM and BEAM.BW) or MachineHeadUse == TWO_EQUAL_HEADS then
          _, sMachiningType = EgtEndsWith( Machining.Type, '_H2')
       end
       -- recupero dati utensile
diff --git a/LuaLibs/ProcessLapJoint.lua b/LuaLibs/ProcessLapJoint.lua
index cb3faf8..46fab69 100644
--- a/LuaLibs/ProcessLapJoint.lua
+++ b/LuaLibs/ProcessLapJoint.lua
@@ -4617,8 +4617,6 @@ end
 
 -- TODO gestione messaggi in funzione apposita (almeno per append)
 
--- TODO gestire topologia tunnel (anche da due lati)
-
 local SawPlusChain =  {}
 SawPlusChain.Saw = {}
 SawPlusChain.Chainsaw = {}
@@ -4681,6 +4679,7 @@ function SawPlusChain.GetTunnelFaces( Proc)
    if TunnelAddedFaces.MiddleFaceTm.Height > TunnelAddedFaces.MiddleFaceTm.Width then
       TunnelAddedFaces.MiddleFaceTm.Height, TunnelAddedFaces.MiddleFaceTm.Width = TunnelAddedFaces.MiddleFaceTm.Width, TunnelAddedFaces.MiddleFaceTm.Height
    end
+   TunnelAddedFaces.MiddleFaceTm.Type = 'Tunnel'
 
    return TunnelAddedFaces
 end
@@ -4712,6 +4711,7 @@ function SawPlusChain.GetBottomFace( Proc)
    end
 
    BottomFace.Id = nBottomFace
+   BottomFace.Type = 'Bottom'
    BottomFace.Width = Proc.Face[nBottomFace + 1].Width
    BottomFace.Height = Proc.Face[nBottomFace + 1].Height
    BottomFace.Elevation = Proc.Face[nBottomFace + 1].Elevation
@@ -4725,6 +4725,7 @@ end
 
 
 function SawPlusChain.GetLongFace( Proc)
+   local LongFace = {}
    if not Proc.MainFaces.BottomFace or not Proc.MainFaces.BottomFace.Id then
       Proc.MainFaces.BottomFace = SawPlusChain.GetBottomFace( Proc)
    end
@@ -4746,10 +4747,10 @@ function SawPlusChain.GetLongFace( Proc)
    end
 
    -- si sceglie la più grande (tunnel) o quella adiacente sul lato lungo
-   local LongFace = {}
    LongFace.Id = FacesToAnalyze[1].Id
    for i = 1, Proc.Fct do
       if LongFace.Id == Proc.Face[i].Id then
+         LongFace.Type = 'Long'
          LongFace.Width = Proc.Face[i].Width
          LongFace.Height = Proc.Face[i].Height
          LongFace.Elevation = Proc.Face[i].Elevation
@@ -4760,8 +4761,6 @@ function SawPlusChain.GetLongFace( Proc)
       end
    end
 
-   LongFace.Edges = SawPlusChain.GetLongFaceEdges( Proc, LongFace)
-
    return LongFace
 end
 
@@ -4799,6 +4798,7 @@ function SawPlusChain.GetSideFaces( Proc)
          ( bIsLongFaceTheLargest and i > 2) then
          table.insert( SideFaces, FacesToAnalyze[i])
          SideFaces[#SideFaces].Id = FacesToAnalyze[i].Id
+         SideFaces[#SideFaces].Type = 'Side'
          SideFaces[#SideFaces].Width = Proc.Face[FacesToAnalyze[i].Id + 1].Width
          SideFaces[#SideFaces].Height = Proc.Face[FacesToAnalyze[i].Id + 1].Height
          SideFaces[#SideFaces].Elevation = Proc.Face[FacesToAnalyze[i].Id + 1].Elevation
@@ -4813,6 +4813,51 @@ function SawPlusChain.GetSideFaces( Proc)
 end
 
 
+function SawPlusChain.GetBottomFaceEdges( Proc, Face)
+   local Edges = {}
+   Edges.SideEdges = {}
+   Edges.LongEdges = {}
+
+   local nFaceType, vEdges = EgtSurfTmGetFacetOutlineInfo( Proc.Id, Face.Id, GDB_ID.ROOT)
+   if nFaceType < 1 then
+      for j = 1, #vEdges do
+         local nPreviousEdgeIndex = j - 1
+         if j == 1 then
+            nPreviousEdgeIndex = #vEdges
+         end
+         local nNextEdgeIndex = j + 1
+         if j == #vEdges then
+            nNextEdgeIndex = 1
+         end
+
+         local CurrentEdge = {}
+         CurrentEdge.AdjacentFaceId = vEdges[j].Adj
+         CurrentEdge.ToolDirection = Vector3d( vEdges[j].Norm)
+         CurrentEdge.Length = vEdges[j].Len
+         CurrentEdge.Elevation = vEdges[j].Elev
+         CurrentEdge.IsOpen = vEdges[j].Open
+         CurrentEdge.IsStartOpen = ( vEdges[nPreviousEdgeIndex].Open)
+         CurrentEdge.IsEndOpen = ( vEdges[nNextEdgeIndex].Open)
+
+         if CurrentEdge.AdjacentFaceId == Proc.MainFaces.LongFace.Id then
+            table.insert( Edges.LongEdges, CurrentEdge)
+            Edges.LongEdges[#Edges.LongEdges].Type = 'Long'
+         elseif vEdges[nNextEdgeIndex].Adj == Proc.MainFaces.LongFace.Id or vEdges[nPreviousEdgeIndex].Adj == Proc.MainFaces.LongFace.Id then
+            table.insert( Edges.SideEdges, CurrentEdge)
+            Edges.SideEdges[#Edges.SideEdges].Type = 'Side'
+         else
+            table.insert( Edges.LongEdges, CurrentEdge)
+            Edges.LongEdges[#Edges.LongEdges].Type = 'Long'
+         end
+      end
+   else
+      error( 'Face with closed hole')
+   end
+
+   return Edges
+end
+
+
 function SawPlusChain.GetLongFaceEdges( Proc, Face)
    local Edges = {}
    Edges.SideEdges = {}
@@ -4848,12 +4893,16 @@ function SawPlusChain.GetLongFaceEdges( Proc, Face)
          else
             if CurrentEdge.AdjacentFaceId == Proc.MainFaces.BottomFace.Id then
                Edges.BottomEdge = CurrentEdge
+               Edges.BottomEdge.Type = 'Bottom'
             elseif vEdges[nNextEdgeIndex].Adj == Proc.MainFaces.BottomFace.Id then
                Edges.SideEdges.StartEdge = CurrentEdge
+               Edges.SideEdges.StartEdge.Type = 'Side'
             elseif vEdges[nPreviousEdgeIndex].Adj == Proc.MainFaces.BottomFace.Id then
                Edges.SideEdges.EndEdge = CurrentEdge
+               Edges.SideEdges.EndEdge.Type = 'Side'
             else
                table.insert( Edges.OppositeEdges, CurrentEdge)
+               Edges.OppositeEdges[#Edges.OppositeEdges].Type = 'Opposite'
             end
          end
       end
@@ -5081,7 +5130,11 @@ function SawPlusChain.Saw.CalculateMachiningParameters( Proc, FaceToMachine, Edg
    if Proc.Topology == 'Tunnel' then
       dPocketHeight = Proc.MainFaces.TunnelAddedFaces.MiddleFaceTm.Height
    else
-      dPocketHeight = Proc.MainFaces.BottomFace.Height
+      if FaceToMachine.Type == 'Long' then
+         dPocketHeight = Proc.MainFaces.BottomFace.Edges.SideEdges[1].Length
+      elseif FaceToMachine.Type == 'Side' then
+         dPocketHeight = Proc.MainFaces.BottomFace.Edges.LongEdges[1].Length
+      end
    end
 
    -- ricerca lavorazione
@@ -5242,32 +5295,43 @@ function SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, FaceToMachine
    Mortising.CanApply = true
    Mortising.Message = ''
    Mortising.ProcId = Proc.Id
+   local bNeedToMachineOtherSide = false
    local dTestCornerRadius = 43
+   -- OneSide | OneSideAndExtend | BothSides | BothSidesAndExtend
    local sMortisingType
    
    local dPocketHeight = 0
    if Proc.Topology == 'Tunnel' then
       dPocketHeight = Proc.MainFaces.TunnelAddedFaces.MiddleFaceTm.Height
    else
-      dPocketHeight = Proc.MainFaces.BottomFace.Height
+      if FaceToMachine.Type == 'Long' then
+         dPocketHeight = Proc.MainFaces.BottomFace.Edges.SideEdges[1].Length
+      elseif FaceToMachine.Type == 'Side' then
+         dPocketHeight = Proc.MainFaces.BottomFace.Edges.LongEdges[1].Length
+      end
    end
 
    -- ricerca lavorazione
    if Proc.Topology == 'Tunnel' then
       Mortising.Name = ML.FindSawing( 'Sawing', abs( EdgeToMachine.Elevation) + dTestCornerRadius + BD.CUT_EXTRA_MIN)
-      sMortisingType = "OneSideAndExtend"
+      sMortisingType = 'OneSideAndExtend'
       if not Mortising.Name then
          Mortising.Name = ML.FindSawing( 'Sawing', abs( EdgeToMachine.Elevation) / 2 + dTestCornerRadius + BD.CUT_EXTRA_MIN)
-         sMortisingType = "BothSidesAndExtend"
+         sMortisingType = 'BothSidesAndExtend'
       end
+   elseif EdgeToMachine.Type == 'Side' and #( Proc.MainFaces.SideFaces) == 0 then
+      Mortising.Name = ML.FindSawing( 'Sawing', abs( EdgeToMachine.Elevation) / 2 + dTestCornerRadius + BD.CUT_EXTRA_MIN)
+      sMortisingType = 'BothSidesAndExtend'
    else
       Mortising.Name = ML.FindSawing( 'Sawing', abs( EdgeToMachine.Elevation))
-      sMortisingType = "OneSide"
+      sMortisingType = 'OneSide'
    end
    if not Mortising.Name then
       Mortising.Name = ML.FindSawing( 'Sawing', nil, nil, 'Longest')
-      if Proc.Topology == 'Tunnel' then
-         sMortisingType = "BothSides"
+      if sMortisingType == 'BothSidesAndExtend' then
+         sMortisingType = 'BothSides'
+      elseif sMortisingType == 'OneSideAndExtend' then
+         sMortisingType = 'OneSide'
       end
    end
    if not Mortising.Name then
@@ -5311,14 +5375,16 @@ function SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, FaceToMachine
       Mortising.ToolInvert = true
    end
    -- profondità e offset longitudinale
-   if sMortisingType == "OneSide" then
+   if sMortisingType == 'OneSide' then
       Mortising.Depth = abs( EdgeToMachine.Elevation)
    elseif sMortisingType == 'OneSideAndExtend' then
       Mortising.Depth = abs( EdgeToMachine.Elevation) + Mortising.Tool.CornerRadius + BD.CUT_EXTRA_MIN
    elseif sMortisingType == 'BothSides' then
       Mortising.Depth = abs( EdgeToMachine.Elevation) / 2
+      bNeedToMachineOtherSide = true
    elseif sMortisingType == 'BothSidesAndExtend' then
       Mortising.Depth = abs( EdgeToMachine.Elevation) / 2 + Mortising.Tool.CornerRadius + BD.CUT_EXTRA_MIN
+      bNeedToMachineOtherSide = true
    end
    if Mortising.Tool.MaxMat > Mortising.Depth - 10 * GEO.EPS_SMALL then
       if EdgeToMachine.Elevation > -10 * GEO.EPS_SMALL then
@@ -5379,7 +5445,7 @@ function SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, FaceToMachine
       EgtOutLog( sDamageNextPieceMessage)
    end
 
-   return Mortising
+   return Mortising, bNeedToMachineOtherSide
 end
 
 
@@ -5434,7 +5500,10 @@ function SawPlusChain.Make( bOnlySaw, Proc, nRawId)
    Proc.MainFaces.SideFaces = SawPlusChain.GetSideFaces( Proc)
    if Proc.Topology == 'Tunnel' then
       Proc.MainFaces.TunnelAddedFaces = SawPlusChain.GetTunnelFaces( Proc)
+   else
+      Proc.MainFaces.BottomFace.Edges = SawPlusChain.GetBottomFaceEdges( Proc, Proc.MainFaces.BottomFace)
    end
+   Proc.MainFaces.LongFace.Edges = SawPlusChain.GetLongFaceEdges( Proc, Proc.MainFaces.LongFace)
 
    -- lama
    -- lavorazione di lama - fondo della tasca o fino a massimo materiale se tunnel
@@ -5452,7 +5521,6 @@ function SawPlusChain.Make( bOnlySaw, Proc, nRawId)
       return bIsCuttingOk, Cutting.Message
    end
    local dBottomDepthToMachine = Cutting.RadialOffset
-
    -- lato opposto del tunnel
    if Proc.Topology == 'Tunnel' then
       Cutting = SawPlusChain.Saw.CalculateMachiningParameters( Proc, Proc.MainFaces.LongFace, Proc.MainFaces.LongFace.Edges.OppositeEdges[2])
@@ -5501,8 +5569,9 @@ function SawPlusChain.Make( bOnlySaw, Proc, nRawId)
    -- sega a catena
    -- parametri lavorazione con sega a catena - fondo della tasca o tunnel
    local Mortising = {}
+   local bNeedToMachineOtherSide = false
    if Proc.Topology == 'Tunnel' then
-      Mortising = SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, Proc.MainFaces.LongFace, Proc.MainFaces.LongFace.Edges.OppositeEdges[1])
+      Mortising, bNeedToMachineOtherSide = SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, Proc.MainFaces.LongFace, Proc.MainFaces.LongFace.Edges.OppositeEdges[1])
    else
       Mortising = SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, Proc.MainFaces.LongFace, Proc.MainFaces.LongFace.Edges.BottomEdge)
       -- si lavora solo quanto non lavorato dalla lama
@@ -5512,9 +5581,8 @@ function SawPlusChain.Make( bOnlySaw, Proc, nRawId)
    if Mortising.CanApply then
       bIsMortisingOk, Mortising.Message = SawPlusChain.Chainsaw.ApplyAllSteps( Mortising, b3Raw)
    end
-
    -- lato opposto del tunnel
-   if Proc.Topology == 'Tunnel' then
+   if Proc.Topology == 'Tunnel' and bNeedToMachineOtherSide then
       Mortising = SawPlusChain.Chainsaw.CalculateMachiningParameters( Proc, Proc.MainFaces.LongFace, Proc.MainFaces.LongFace.Edges.OppositeEdges[2])
       bIsMortisingOk = false
       if Mortising.CanApply then
diff --git a/UpdateLog.txt b/UpdateLog.txt
index b488a6d..4b5231d 100644
--- a/UpdateLog.txt
+++ b/UpdateLog.txt
@@ -1,5 +1,9 @@
            ==== Beam Update Log ====
 
+Versione 2.6e4 (20/05/2024)
+- Modif : in SawPlusChain le lavorazioni di sega a catena aggiuntive (side) si fermano in mezzeria se tasca passante
+- Modif : in SawPlusChain il tunnel con sega a catena viene fatto da un solo lato se possibile
+
 Versione 2.6e3 (14/05/2024)
 - Modif : in SawPlusChain aggiunta gestione lavorazioni aggiuntive lati aperti e tunnel
 - Fixed : in Cut -> MakeFromTop ricalcolo direzione di lavorazione su facce a cubetti.
diff --git a/Version.lua b/Version.lua
index 3dd5ccb..6dcb1ad 100644
--- a/Version.lua
+++ b/Version.lua
@@ -2,5 +2,5 @@
 -- Gestione della versione di Beam
 
 NAME = 'Beam'
-VERSION = '2.6e3'
+VERSION = '2.6e4'
 MIN_EXE = '2.6e2'