diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index b4acb7d..e39fb9e 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ
diff --git a/SfrCreate.cpp b/SfrCreate.cpp
index 752d7a0..afe0871 100644
--- a/SfrCreate.cpp
+++ b/SfrCreate.cpp
@@ -119,9 +119,13 @@ GetSurfFlatRegionFromFatCurve( ICurve* pCrv, double dRadius, bool bSquareEnds, b
    if ( IsNull( pCurve))
       return nullptr ;
   // la inserisco in una curva composita
+   Vector3d vtExtr ; pCrv->GetExtrusion( vtExtr) ;
+   if ( vtExtr.IsSmall())
+      vtExtr = Z_AX ;
    PtrOwner<CurveComposite> pCompo1( CreateBasicCurveComposite()) ;
    if ( IsNull( pCompo1)  ||  ! pCompo1->AddCurve( Release( pCurve)))
       return nullptr ;
+   pCompo1->SetExtrusion( vtExtr) ;
   // se distanza tra gli estremi minore di due volte il raggio la chiudo, purchè curva abbastanza lunga
    Point3d ptStart, ptEnd, ptMid ;
    Vector3d vtStart, vtEnd ;
@@ -228,12 +232,12 @@ GetSurfFlatRegionFromFatCurve( ICurve* pCrv, double dRadius, bool bSquareEnds, b
             return nullptr ;
         // verifico se arco tangente alla prima o alla seconda curva
          if ( AreSameVectorApprox( vtEnd1, vtEnd)) {
-            if ( ! pArc1->Set2PVN( ptEnd1, ptStart2, vtEnd1, Z_AX)  ||
+            if ( ! pArc1->Set2PVN( ptEnd1, ptStart2, vtEnd1, vtExtr)  ||
                  ! pCompo1->AddCurve( Release( pArc1)))
                return nullptr ;
          }
          else {
-            if ( ! pArc1->Set2PVN( ptStart2, ptEnd1, -vtStart2, Z_AX)  ||
+            if ( ! pArc1->Set2PVN( ptStart2, ptEnd1, -vtStart2, vtExtr)  ||
                  ! pArc1->Invert()  ||
                  ! pCompo1->AddCurve( Release( pArc1)))
                return nullptr ;
@@ -250,12 +254,12 @@ GetSurfFlatRegionFromFatCurve( ICurve* pCrv, double dRadius, bool bSquareEnds, b
             return nullptr ;
         // verifico se arco tangente alla seconda o alla prima curva
          if ( AreOppositeVectorApprox( vtEnd2, vtStart)) {
-            if ( ! pArc2->Set2PVN( ptEnd2, ptStart1, vtEnd2, Z_AX)  ||
+            if ( ! pArc2->Set2PVN( ptEnd2, ptStart1, vtEnd2, vtExtr)  ||
                  ! pCompo2->AddCurve( Release( pArc2)))
                return nullptr ;
          }
          else {
-            if ( ! pArc2->Set2PVN( ptStart1, ptEnd2, -vtStart1, Z_AX)  ||
+            if ( ! pArc2->Set2PVN( ptStart1, ptEnd2, -vtStart1, vtExtr)  ||
                  ! pArc2->Invert()  ||
                  ! pCompo2->AddCurve( Release( pArc2)))
                return nullptr ;