diff --git a/EInAPI.h b/EInAPI.h
index a74f3bb..93b232a 100644
--- a/EInAPI.h
+++ b/EInAPI.h
@@ -489,7 +489,7 @@ EIN_EXPORT BOOL __stdcall EgtCurveCompoCenter( int nId, int nSimpCrv, int nRefId
 EIN_EXPORT BOOL __stdcall EgtSurfFrNormVersor( int nId, int nRefId, double vtNorm[3]) ;
 EIN_EXPORT BOOL __stdcall EgtSurfFrGrossArea( int nId, double* pdArea) ;
 EIN_EXPORT int  __stdcall EgtSurfFrChunkCount( int nId) ;
-EIN_EXPORT int  __stdcall EgtSurfFrChunkSimpleClassify( int nId1, int nChunk1, int nId2, int nChunk2) ;
+EIN_EXPORT int  __stdcall EgtSurfFrChunkSimpleClassify( int nId1, int nChunk1, int nId2, int nChunk2, double dToler) ;
 EIN_EXPORT int  __stdcall EgtExtractSurfFrChunkLoops( int nId, int nChunk, int nDestGrpId, int* pnCount) ;
 EIN_EXPORT int  __stdcall EgtSurfTmFacetCount( int nId) ;
 EIN_EXPORT int  __stdcall EgtSurfTmFacetFromTria( int nId, int nT) ;
diff --git a/EMkMachiningGeoConst.h b/EMkMachiningGeoConst.h
index ad5ae8d..c833593 100644
--- a/EMkMachiningGeoConst.h
+++ b/EMkMachiningGeoConst.h
@@ -67,6 +67,11 @@ static std::string MCH_PV_KEY_RELOCATE = "PvId" ;
 // Chiave info per angoli in XY con entità successiva e precedente
 static std::string MCH_KEY_NEXTANG = "NextAng" ;
 static std::string MCH_KEY_PREVANG = "PrevAng" ;
+// Chiave info per direzione libera in XY all'inizio e alla fine dell'entità (in assenza infinito)
+static std::string MCH_KEY_START_FREELEN = "SFL" ;
+static std::string MCH_KEY_END_FREELEN = "EFL" ;
+// Angolo esterno minimo per calcolare la direzione libera sull'arco
+static double FL_ARC_ANG_MIN = 30 ;
 // Chiave info per baffo (whiskers) di taglio lama da allungare
 static std::string MCH_KEY_START_WHISKEXT = "SWE" ;
 static std::string MCH_KEY_END_WHISKEXT = "EWE" ;
diff --git a/EXeExecutor.h b/EXeExecutor.h
index ef9959d..b4905be 100644
--- a/EXeExecutor.h
+++ b/EXeExecutor.h
@@ -575,7 +575,7 @@ EXE_EXPORT bool ExeSurfFrNormVersor( int nId, int nRefId, Vector3d& vtNorm) ;
 EXE_EXPORT bool ExeSurfFrGrossArea( int nId, double& dArea) ;
 EXE_EXPORT bool ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist) ;
 EXE_EXPORT int  ExeSurfFrChunkCount( int nId) ;
-EXE_EXPORT int  ExeSurfFrChunkSimpleClassify( int nId1, int nChunk1, int nId2, int nChunk2) ;
+EXE_EXPORT int  ExeSurfFrChunkSimpleClassify( int nId1, int nChunk1, int nId2, int nChunk2, double dToler = 0) ;
 EXE_EXPORT int  ExeExtractSurfFrChunkLoops( int nId, int nChunk, int nDestGrpId, int* pnCount) ;
 EXE_EXPORT int  ExeSurfTmFacetCount( int nId) ;
 EXE_EXPORT int  ExeSurfTmFacetFromTria( int nId, int nT) ;