diff --git a/BtlGeom.cpp b/BtlGeom.cpp
index eeb5714..0457c6c 100644
--- a/BtlGeom.cpp
+++ b/BtlGeom.cpp
@@ -579,3 +579,40 @@ BtlGeom::SetAlpha( int nId, int nAlpha)
    cCol.SetAlpha( nAlpha) ;
    return m_pGDB->SetMaterial( nId, cCol) ;
 }
+
+//----------------------------------------------------------------------------
+bool
+BtlGeom::SortParts( void)
+{
+  // tabella Id-SN dei pezzi
+   INTINTVECTOR vIdSN ;
+
+  // recupero il numero di serie di ogni singolo pezzo
+   int nPartId = m_pGDB->GetFirstGroupInGroup( GDB_ID_ROOT) ;
+   while ( nPartId != GDB_ID_NULL) {
+      int nLev ;
+      if ( m_pGDB->GetCalcLevel( nPartId, nLev)  &&  nLev == GDB_LV_USER) {
+         int nSN = 0 ;
+         m_pGDB->GetInfo( nPartId, IKEY_PROD_NBR, nSN) ;
+         vIdSN.emplace_back( nPartId, nSN) ;
+      }
+      nPartId = m_pGDB->GetNextGroup( nPartId) ;
+   }
+
+  // ordino la tabella secondo SN
+   sort( vIdSN.begin(), vIdSN.end(), []( const INTINT& a, const INTINT& b)
+                                       { return a.second < b.second ; }) ;
+
+  // cambio posizione dei pezzi nel DB come da ordine in tabella
+   Point3d ptIns ;
+   for ( int i = 0 ; i < int( vIdSN.size()) ; ++ i) {
+      m_pGDB->Relocate( vIdSN[i].first, GDB_ID_ROOT, GDB_LAST_SON) ;
+      BBox3d b3Part ;
+      int nBoxId = m_pGDB->GetFirstNameInGroup( vIdSN[i].first, BOX_LAYER_NAME) ;
+      m_pGDB->GetGlobalBBox( nBoxId, b3Part) ;
+      m_pGDB->Translate( vIdSN[i].first, ptIns - b3Part.GetMin()) ;
+      ptIns += Vector3d( 0, b3Part.GetMax().y - b3Part.GetMin().y + 300, 0) ;
+   }
+
+   return true ;
+}
\ No newline at end of file
diff --git a/BtlGeom.h b/BtlGeom.h
index 3a60730..73a0d36 100644
--- a/BtlGeom.h
+++ b/BtlGeom.h
@@ -39,6 +39,7 @@ class BtlGeom
       bool AdjustPartFlatOrVertPos( int nPartId) ;
       std::string GetPartName( void) ;
       bool SetUserAttribute( int nUAttrDest, const std::string& sString) ;
+      bool SortParts( void) ;
 
    public :              // Outline
       bool AddPartOutline( int nSide, const FCEDEQUE& dqFce) ;
@@ -150,7 +151,7 @@ class BtlGeom
                          const INTVECTOR& vnDPar, const DBLVECTOR& vdPar, const STRVECTOR& vsUAtt) ;
       bool AddFreeContour( int nGroup, int nProc, int nSide, const std::string& sDes, int nProcId, const Frame3d& frRef,
                            const INTVECTOR& vnDPar, int nSPar, const DBLVECTOR& vdPar, const std::string& sPar, const STRVECTOR& vsUAtt) ;
-      bool CreatePolygonInBox( const Point3d& ptP, const Vector3d& vtN, int nSide, Polygon3d& Polyg) ;
+      bool CreatePolygonInBox( const Point3d& ptP, const Vector3d& vtN, int nSide, Polygon3d& Polyg, double dMinDim = FACE_MIN_CROSS_DIM) ;
       bool TrimPolygons( Polygon3d& plyP1, Polygon3d& plyP2, bool bInVsOut, bool bOnEq) ;
       bool VerifyPolygon( Polygon3d& plyP, double dMinDim = FACE_MIN_CROSS_DIM) ;
       bool VerifyPolygonWithPolygon( Polygon3d& plyP, const Polygon3d& plyRef, bool bInVsOut, double dMinDim = FACE_MIN_CROSS_DIM) ;
diff --git a/BtlGeomProc.cpp b/BtlGeomProc.cpp
index d7fe6bc..e57565c 100644
--- a/BtlGeomProc.cpp
+++ b/BtlGeomProc.cpp
@@ -4260,7 +4260,7 @@ BtlGeom::AddFreeContour( int nGroup, int nProc, int nSide, const string& sDes, i
 
 //----------------------------------------------------------------------------
 bool
-BtlGeom::CreatePolygonInBox( const Point3d& ptP, const Vector3d& vtN, int nSide, Polygon3d& Polyg)
+BtlGeom::CreatePolygonInBox( const Point3d& ptP, const Vector3d& vtN, int nSide, Polygon3d& Polyg, double dMinDim)
 {
   // calcolo il piano
    Plane3d plPlane ;
@@ -4272,7 +4272,29 @@ BtlGeom::CreatePolygonInBox( const Point3d& ptP, const Vector3d& vtN, int nSide,
       plPlane.ToGlob( frRef) ;
    }
   // creo il poligono, limitandolo al box dell'oggetto (trave/parete)
-   return Polyg.FromPlaneTrimmedWithBox( plPlane, ORIG, ORIG + m_vtDim) ;
+   if ( ! Polyg.FromPlaneTrimmedWithBox( plPlane, ORIG, ORIG + m_vtDim))
+      return false ;
+  // verifico che il materiale lasciato non sia inferiore al minimo
+   for ( int nS = BTL_SIDE_FRONT ; nS < BTL_SIDE_LEFT ; ++ nS) {
+     // confronto con ogni faccia del box della trave quasi opposta
+      Plane3d plFace = GetSidePlane( nS) ;
+      if ( plPlane.GetVersN() * plFace.GetVersN() < -0.5) {
+        // cerco minima profondità negativa 
+         PNTVECTOR vVert = Polyg.GetVertices() ;
+         double dMinDist = 0 ;
+         for ( const auto& ptV : vVert) {
+            double dDist = DistPointPlane( ptV, plFace) ;
+            if ( dDist < dMinDist)
+               dMinDist = dDist ;
+         }
+        // se profondità non sufficicente, allora elimino la faccia
+         if ( dMinDist > - abs( dMinDim)) {
+            Polyg.Clear() ;
+            break ;
+         }
+      }
+   }
+   return true ;
 }
 
 //----------------------------------------------------------------------------
diff --git a/EgtExchange.rc b/EgtExchange.rc
index 2cd4f7b..d4ad2d3 100644
Binary files a/EgtExchange.rc and b/EgtExchange.rc differ
diff --git a/ImportBtl.cpp b/ImportBtl.cpp
index cac0b5d..45c2dea 100644
--- a/ImportBtl.cpp
+++ b/ImportBtl.cpp
@@ -149,6 +149,11 @@ ImportBtl::Import( const string& sFile, IGeomDB* pGDB, int nFlag)
       }
    }
 
+  // eventuale ordinamento dei pezzi secondo SN
+   bool bSort = (( nFlag & EIBFLAG_SORT) != 0) ;
+   if ( bSort)
+      m_BtlGeom.SortParts() ;
+
    return bOk ;
 }