diff --git a/EXE_NstPartNesting.cpp b/EXE_NstPartNesting.cpp
index 6d686da..1db4a5a 100644
--- a/EXE_NstPartNesting.cpp
+++ b/EXE_NstPartNesting.cpp
@@ -539,8 +539,20 @@ ExePackPartCluster( const INTVECTOR& vIds, bool bReducedCut, bool bBottomUp)
    double dRegClDimX = b3RegCluster.GetMax().x - b3RegCluster.GetMin().x ;
    double dRegClDimY = b3RegCluster.GetMax().y - b3RegCluster.GetMin().y ;
 
+  // Determino lo step per i tentativi di inserimento
+   const double STEP_STD = 50 ;
+   double dStepX = STEP_STD ;
+   double dStepY = STEP_STD ;
+   double dBoxDimX = b3Box.GetMax().x - b3Box.GetMin().x ;
+   double dRegCluDimX = b3RegCluster.GetMax().x - b3RegCluster.GetMin().x ;
+   if ( dBoxDimX - dRegCluDimX < 5 * STEP_STD)
+      dStepX = STEP_STD / 5 ;
+   double dBoxDimY = b3Box.GetMax().y - b3Box.GetMin().y ;
+   double dRegCluDimY = b3RegCluster.GetMax().y - b3RegCluster.GetMin().y ;
+   if ( dBoxDimY - dRegCluDimY < 5 * STEP_STD)
+      dStepY = STEP_STD / 5 ;
+
   // Procedo per tentativi
-   const double STEP = 50 ;
    bool bFit = false ;
    Point3d ptOrig = b3RegCluster.GetMin() ;
    Point3d ptLineStart = ( bBottomUp ? b3Box.GetMin() : b3Box.GetMax() - Vector3d(0, -dRegClDimY, 0)) ;
@@ -559,10 +571,10 @@ ExePackPartCluster( const INTVECTOR& vIds, bool bReducedCut, bool bBottomUp)
          break ;
       }
      // nuova posizione di inserimento (incrementando X)
-      ptIns += Vector3d( STEP, 0, 0) ;
+      ptIns += Vector3d( dStepX, 0, 0) ;
      // se esco dal box torno all'inizio e incremento Y
       if ( ! b3Box.EnclosesXY( ptIns + Vector3d( dRegClDimX, 0, 0))) {
-         ptLineStart += Vector3d( 0, ( bBottomUp ? STEP : - STEP), 0) ;
+         ptLineStart += Vector3d( 0, ( bBottomUp ? dStepY : - dStepY), 0) ;
          if ( ( ! b3Box.EnclosesXY( ptLineStart + Vector3d( 0, dRegClDimY, 0))))
             break ;
          ptIns = ptLineStart ;