diff --git a/EInAPI.h b/EInAPI.h
index 0dd5a04..1371172 100644
--- a/EInAPI.h
+++ b/EInAPI.h
@@ -927,7 +927,8 @@ EIN_EXPORT BOOL __stdcall EgtApplyMachining( BOOL bRecalc) ;
 EIN_EXPORT BOOL __stdcall EgtUpdateMachining( void) ;
 EIN_EXPORT BOOL __stdcall EgtPreparePreviewMachiningTool( void) ;
 EIN_EXPORT BOOL __stdcall EgtRemovePreviewMachiningTool( void) ;
-EIN_EXPORT int  __stdcall EgtPreviewMachiningTool( int nEntId, int nFlag) ;
+EIN_EXPORT int  __stdcall EgtGetPreviewMachiningToolStepCount( void) ;
+EIN_EXPORT int  __stdcall EgtPreviewMachiningTool( int nEntId, int nStep) ;
 EIN_EXPORT BOOL __stdcall EgtGetMachiningParamBool( int nType, BOOL* pbVal) ;
 EIN_EXPORT BOOL __stdcall EgtGetMachiningParamInt( int nType, int* pnVal) ;
 EIN_EXPORT BOOL __stdcall EgtGetMachiningParamDouble( int nType, double* pdVal) ;
diff --git a/EMkMachMgr.h b/EMkMachMgr.h
index e6011f2..1c8d1c3 100644
--- a/EMkMachMgr.h
+++ b/EMkMachMgr.h
@@ -259,7 +259,8 @@ class __declspec( novtable) IMachMgr
       virtual bool MachiningUpdate( bool bPostApply = true) = 0 ;
       virtual bool PreparePreviewMachiningTool( void) const = 0 ;
       virtual bool RemovePreviewMachiningTool( void) const = 0 ;
-      virtual int  PreviewMachiningTool( int nEntId, int nFlag) const = 0 ;
+      virtual int  GetPreviewMachiningToolStepCount( void) const = 0 ; 
+      virtual int  PreviewMachiningTool( int nEntId, int nStep) const = 0 ;
       virtual bool GetMachiningParam( int nType, bool& bVal) const = 0 ;
       virtual bool GetMachiningParam( int nType, int& nVal) const = 0 ;
       virtual bool GetMachiningParam( int nType, double& dVal) const = 0 ;
diff --git a/EXeExecutor.h b/EXeExecutor.h
index 0bd64ba..032bcc4 100644
--- a/EXeExecutor.h
+++ b/EXeExecutor.h
@@ -1177,7 +1177,8 @@ EXE_EXPORT bool ExeApplyMachining( bool bRecalc, bool bPostApply = true) ;
 EXE_EXPORT bool ExeUpdateMachining( bool bPostApply = true) ;
 EXE_EXPORT bool ExePreparePreviewMachiningTool( void) ;
 EXE_EXPORT bool ExeRemovePreviewMachiningTool( void) ;
-EXE_EXPORT int  ExePreviewMachiningTool( int nEntId, int nFlag) ;
+EXE_EXPORT int  ExeGetPreviewMachiningToolStepCount( void) ;
+EXE_EXPORT int  ExePreviewMachiningTool( int nEntId, int nStep) ;
 EXE_EXPORT bool ExeGetMachiningParam( int nType, bool& bVal) ;
 EXE_EXPORT bool ExeGetMachiningParam( int nType, int& nVal) ;
 EXE_EXPORT bool ExeGetMachiningParam( int nType, double& dVal) ;