diff --git a/EGkCircle2P.h b/EGkCircle2P.h
new file mode 100644
index 0000000..2aa1a85
--- /dev/null
+++ b/EGkCircle2P.h
@@ -0,0 +1,28 @@
+//----------------------------------------------------------------------------
+//  EgalTech 2022-202
+//----------------------------------------------------------------------------
+// File : EGkCircle2Pe.h       Data : 18.08.22       Versione : 2.4h2
+// Contenuto : Dichiarazione funzioni per calcolo circonferenze per 2 punti
+//             diametrali.
+//
+//
+// Modifiche : 18.08.22 DS Creazione modulo.
+//
+//
+//----------------------------------------------------------------------------
+
+#pragma once
+
+#include "/EgtDev/Include/EGkCurveArc.h"
+
+
+//----------------------- Macro per import/export ----------------------------
+#undef EGK_EXPORT
+#if defined( I_AM_EGK)            // da definirsi solo nella DLL
+   #define EGK_EXPORT __declspec( dllexport)
+#else
+   #define EGK_EXPORT __declspec( dllimport)
+#endif
+
+//----------------------------------------------------------------------------
+EGK_EXPORT ICurveArc* GetCircle2P( const Point3d& ptP1, const Point3d& ptP2, const Vector3d& vtN) ;
diff --git a/EGkVector3d.h b/EGkVector3d.h
index 2d04dba..1c32a40 100644
--- a/EGkVector3d.h
+++ b/EGkVector3d.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
-//  EgalTech 2013-2019
+//  EgalTech 2013-2022
 //----------------------------------------------------------------------------
-// File : EGkVector3d.h          Data : 14.12.19          Versione : 2.1l4
+// File : EGkVector3d.h          Data : 18.082.22          Versione : 2.4h2
 // Contenuto : Dichiarazione della classe Vettore 3d.
 //
 //
@@ -287,7 +287,10 @@ Media( const Vector3d& vtV1, const Vector3d& vtV2, double dCoeff)
 inline Vector3d 
 ParallCompo( const Vector3d& vtV, const Vector3d& vtRef)
 {
-   return ( ( vtV * vtRef) * vtRef) ;
+   if ( vtRef.IsNormalized())
+      return ( ( vtV * vtRef) * vtRef) ;
+   else
+      return ( ( vtV * vtRef) * vtRef / vtRef.SqLen()) ;
 }
 
 //----------------------------------------------------------------------------
@@ -296,7 +299,10 @@ ParallCompo( const Vector3d& vtV, const Vector3d& vtRef)
 inline Vector3d 
 OrthoCompo( const Vector3d& vtV, const Vector3d& vtRef)
 {
-   return ( vtV - ( vtV * vtRef) * vtRef) ;
+   if ( vtRef.IsNormalized())
+      return ( vtV - ( vtV * vtRef) * vtRef) ;
+   else
+      return ( vtV - ( vtV * vtRef) * vtRef / vtRef.SqLen()) ;
 }
 
 //----------------------------------------------------------------------------
diff --git a/EInAPI.h b/EInAPI.h
index c95d74d..5c7bc7b 100644
--- a/EInAPI.h
+++ b/EInAPI.h
@@ -218,6 +218,8 @@ EIN_EXPORT int  __stdcall EgtCreateCircleCP( int nParentId, const double ptCen[3
                                              const double ptOn[3], int nRefType) ;
 EIN_EXPORT int  __stdcall EgtCreateCircleCPEx( int nParentId, const double ptCen[3],
                                                const double ptOn[3], int nSepO, int nIdO, int nRefType) ;
+EIN_EXPORT int  __stdcall EgtCreateCircle2P( int nParentId, const double ptP1[3],
+                                             const double ptP2[3], int nRefType) ;
 EIN_EXPORT int  __stdcall EgtCreateCircle3P( int nParentId, const double ptP1[3],
                                              const double ptP2[3], const double ptP3[3], int nRefType) ;
 EIN_EXPORT int  __stdcall EgtCreateArc( int nParentId, const double ptCen[3], double dRad,
@@ -485,7 +487,7 @@ EIN_EXPORT int  __stdcall EgtSplitCurve( int nId, int nParts) ;
 EIN_EXPORT int  __stdcall EgtSplitCurveAtPoint( int nId, const double ptOn[3], int nRefType) ;
 EIN_EXPORT BOOL __stdcall EgtModifyCircleCP( int nId, const double ptOn[3], int nRefType) ;
 EIN_EXPORT BOOL __stdcall EgtModifyCircle3P( int nId, const double ptP1[3], const double ptP2[3], const double ptP3[3], int nRefType) ;
-EIN_EXPORT BOOL __stdcall EgtModifyArcRadius( int nId, double dRad) ;
+EIN_EXPORT BOOL __stdcall EgtModifyArcRadius( int nId, double dRad, BOOL bKeepCenter) ;
 EIN_EXPORT BOOL __stdcall EgtModifyArcC2P( int nId, const double ptEnd[3], int nRefType) ;
 EIN_EXPORT BOOL __stdcall EgtModifyArc3P( int nId, const double ptMid[3], int nRefType) ;
 EIN_EXPORT BOOL __stdcall EgtModifyArcByFlip( int nId) ;
diff --git a/EXeExecutor.h b/EXeExecutor.h
index a0542dd..1ea3964 100644
--- a/EXeExecutor.h
+++ b/EXeExecutor.h
@@ -235,6 +235,7 @@ EXE_EXPORT int  ExeCreateCircleCP( int nParentId, const Point3d& ptCen,
                                    const Point3d& ptOn, int nRefType) ;
 EXE_EXPORT int  ExeCreateCircleCPEx( int nParentId, const Point3d& ptCen,
                                      const Point3d& ptOn, int nSepO, int nIdO, int nRefType) ;
+EXE_EXPORT int  ExeCreateCircle2P( int nParentId, const Point3d& ptP1, const Point3d& ptP2, int nRefType) ;
 EXE_EXPORT int  ExeCreateCircle3P( int nParentId, const Point3d& ptP1,
                                    const Point3d& ptP2, const Point3d& ptP3, int nRefType) ;
 EXE_EXPORT int  ExeCreateArc( int nParentId, const Point3d& ptCen, double dRad,
@@ -531,7 +532,7 @@ EXE_EXPORT int  ExeSplitCurveAtSelfInters( int nId, int* pnCount) ;
 EXE_EXPORT int  ExeGetCurveLinearConvexHullXY( int nId, double dLinTol, int nRefType) ;
 EXE_EXPORT bool ExeModifyCircleCP( int nId, const Point3d& ptOn, int nRefType) ;
 EXE_EXPORT bool ExeModifyCircle3P( int nId, const Point3d& ptP1, const Point3d& ptP2, const Point3d& ptP3, int nRefType) ;
-EXE_EXPORT bool ExeModifyArcRadius( int nId, double dRad) ;
+EXE_EXPORT bool ExeModifyArcRadius( int nId, double dRad, bool bKeepCenter = true) ;
 EXE_EXPORT bool ExeModifyArcC2P( int nId, const Point3d& ptEnd, int nRefType) ;
 EXE_EXPORT bool ExeModifyArc3P( int nId, const Point3d& ptMid, int nRefType) ;
 EXE_EXPORT bool ExeModifyArcToExplementary( int nId) ;