diff --git a/MachOptionsWindow/MachOptionsView.xaml b/MachOptionsWindow/MachOptionsView.xaml
index 9de4631..986cdd6 100644
--- a/MachOptionsWindow/MachOptionsView.xaml
+++ b/MachOptionsWindow/MachOptionsView.xaml
@@ -7,14 +7,14 @@
    TitleBarBrush="{StaticResource EgaltechBlue1}"
    BorderBrush="{StaticResource EgaltechBlue1}"
    WindowStyle="None" ResizeMode="NoResize" TitleBarHeight="30" IsResizable="False"
-   IsMinimizable="False" WindowStartupLocation="CenterScreen" ShowInTaskbar="False"
+   IsMinimizable="False" WindowStartupLocation="CenterOwner" ShowInTaskbar="False"
    CloseCommand="{Binding CloseMachOptionsCommand, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" SizeToContent="WidthAndHeight">
 
    <EgtWPFLib5:EgtCustomWindow.Resources>
       <local:SplitArcTypeConverter x:Key="SplitArcTypeConverter"/>
    </EgtWPFLib5:EgtCustomWindow.Resources>
 
-   <Grid Margin="5">
+   <Grid Margin="10">
       <Grid.ColumnDefinitions>
          <ColumnDefinition Width="1*"/>
          <ColumnDefinition Width="1*"/>
@@ -26,21 +26,27 @@
          <RowDefinition Height="Auto"/>
          <RowDefinition Height="Auto"/>
          <RowDefinition Height="Auto"/>
+         <RowDefinition Height="Auto"/>
       </Grid.RowDefinitions>
 
       <UniformGrid Grid.Row="0" Columns="2" Margin="0,0,0,5">
          <TextBlock Text="{Binding SafeZMsg}" VerticalAlignment="Center"/>
-         <TextBox Text="{Binding SafeZ}" Height="25" Margin="5,0,0,0"/>
+         <TextBox Text="{Binding SafeZ}" Height="25" Margin="10,0,0,0"/>
       </UniformGrid>
 
       <UniformGrid Grid.Row="1" Columns="2" Margin="0,0,0,5">
          <TextBlock Text="{Binding SafeAggrBottZMsg}" VerticalAlignment="Center"/>
-         <TextBox Text="{Binding SafeAggrBottZ}" Height="25" Margin="5,0,0,0"/>
+         <TextBox Text="{Binding SafeAggrBottZ}" Height="25" Margin="10,0,0,0"/>
       </UniformGrid>
 
       <UniformGrid Grid.Row="2" Columns="2" Margin="0,0,0,5">
+         <TextBlock Text="{Binding HolesToleranceMsg}" VerticalAlignment="Center"/>
+         <TextBox Text="{Binding HolesTolerance}" Height="25" Margin="10,0,0,0"/>
+      </UniformGrid>
+
+      <UniformGrid Grid.Row="3" Columns="2" Margin="0,0,0,5">
          <TextBlock Text="{Binding SplitArcsMsg}" VerticalAlignment="Center"/>
-         <ComboBox ItemsSource="{Binding SplitArcsList}" Height="25" Margin="5,0,0,0"
+         <ComboBox ItemsSource="{Binding SplitArcsList}" Height="25" Margin="10,0,0,0"
             SelectedItem="{Binding SelectedSplitArcs}">
             <ComboBox.ItemTemplate>
                <DataTemplate>
@@ -50,9 +56,9 @@
          </ComboBox>
       </UniformGrid>
 
-      <UniformGrid Grid.Row="3" Columns="2">
+      <UniformGrid Grid.Row="4" Columns="2">
          <TextBlock Text="{Binding DefaultSetUpMsg}" VerticalAlignment="Center"/>
-         <ComboBox ItemsSource="{Binding ArchivedSetUpList}" Height="25" Margin="5,0,0,0"
+         <ComboBox ItemsSource="{Binding ArchivedSetUpList}" Height="25" Margin="10,0,0,0"
             SelectedItem="{Binding SelectedDefaultSetUp}" IsEnabled="{Binding IsActiveDefaultSetUp}"/>
       </UniformGrid>
 
diff --git a/MachOptionsWindow/MachOptionsViewModel.vb b/MachOptionsWindow/MachOptionsViewModel.vb
index 5093081..b6046af 100644
--- a/MachOptionsWindow/MachOptionsViewModel.vb
+++ b/MachOptionsWindow/MachOptionsViewModel.vb
@@ -5,31 +5,48 @@ Namespace EgtCAM5
 
    Public Class MachOptionsViewModel
 
-      Private m_dSafeZ As String
+      Private m_sSafeZ As String
       Public Property SafeZ As String
          Get
-            Return m_dSafeZ
+            Return m_sSafeZ
          End Get
          Set(value As String)
             Dim dSafeZ As Double = 0
-            StringToLen(value, dSafeZ)
-            EgtMdbSetGeneralParam(MCH_GP.SAFEZ, dSafeZ)
-            EgtMdbSave()
-            m_dSafeZ = value
+            If StringToLen(value, dSafeZ) Then
+               EgtMdbSetGeneralParam(MCH_GP.SAFEZ, dSafeZ)
+               EgtMdbSave()
+               m_sSafeZ = value
+            End If
          End Set
       End Property
 
-      Private m_dSafeAggrBottZ As String
+      Private m_sSafeAggrBottZ As String
       Public Property SafeAggrBottZ As String
          Get
-            Return m_dSafeAggrBottZ
+            Return m_sSafeAggrBottZ
          End Get
          Set(value As String)
             Dim dSafeAggrBottZ As Double = 0
-            StringToLen(value, dSafeAggrBottZ)
-            EgtMdbSetGeneralParam(MCH_GP.SAFEAGGRBOTTZ, dSafeAggrBottZ)
-            EgtMdbSave()
-            m_dSafeAggrBottZ = value
+            If StringToLen(value, dSafeAggrBottZ) Then
+               EgtMdbSetGeneralParam(MCH_GP.SAFEAGGRBOTTZ, dSafeAggrBottZ)
+               EgtMdbSave()
+               m_sSafeAggrBottZ = value
+            End If
+         End Set
+      End Property
+
+      Private m_sHolesTolerance As String
+      Public Property HolesTolerance As String
+         Get
+            Return m_sHolesTolerance
+         End Get
+         Set(value As String)
+            Dim dHolesTolerance As Double = 0
+            If StringToLen(value, dHolesTolerance) Then
+               EgtMdbSetGeneralParam(MCH_GP.HOLEDIAMTOLER, dHolesTolerance)
+               EgtMdbSave()
+               m_sHolesTolerance = value
+            End If
          End Set
       End Property
 
@@ -86,6 +103,12 @@ Namespace EgtCAM5
          End Get
       End Property
 
+      Public ReadOnly Property HolesToleranceMsg As String
+         Get
+            Return EgtMsg(MSG_MACHININGOPTIONPAGE + 9)
+         End Get
+      End Property
+
       Public ReadOnly Property SplitArcsMsg As String
          Get
             Return EgtMsg(MSG_MACHININGOPTIONPAGE + 2)
@@ -107,23 +130,29 @@ Namespace EgtCAM5
          ' Leggo distanza di sicurezza
          Dim dVal As Double = 0
          EgtMdbGetGeneralParam(MCH_GP.SAFEZ, dVal)
-         m_dSafeZ = LenToString(dVal, 2)
+         m_sSafeZ = LenToString(dVal, 2)
          ' Leggo distanza di sicurezza per rinvii da sotto
          dVal = 0
          EgtMdbGetGeneralParam(MCH_GP.SAFEAGGRBOTTZ, dVal)
-         m_dSafeAggrBottZ = LenToString(dVal, 2)
+         m_sSafeAggrBottZ = LenToString(dVal, 2)
+         ' Leggo tolleranza tra diametro punta e diametro foro
+         dVal = 0
+         EgtMdbGetGeneralParam(MCH_GP.HOLEDIAMTOLER, dVal)
+         m_sHolesTolerance = LenToString(dVal, 2)
          ' Leggo tipo di spezzatura archi
          Dim nVal As Integer = 0
          EgtMdbGetGeneralParam(MCH_GP.SPLITARCS, nVal)
          m_SelectedSplitArcs = DirectCast(nVal, MCH_SA)
          ' Riempio lista attrezzaggi salvati
          m_ArchivedSetUpList.Add(String.Empty)
-         Dim SetUpFileNames() As String = Directory.GetFiles(IniFile.m_sCurrMachSetUpDirPath)
-         For FileIndex = 0 To SetUpFileNames.Count - 1
-            If Path.GetExtension(SetUpFileNames(FileIndex)).ToLower = ".stu" Then
-               m_ArchivedSetUpList.Add(Path.GetFileNameWithoutExtension(SetUpFileNames(FileIndex)))
-            End If
-         Next
+         If Directory.Exists(IniFile.m_sCurrMachSetUpDirPath) Then
+            Dim SetUpFileNames() As String = Directory.GetFiles(IniFile.m_sCurrMachSetUpDirPath)
+            For FileIndex = 0 To SetUpFileNames.Count - 1
+               If Path.GetExtension(SetUpFileNames(FileIndex)).ToLower = ".stu" Then
+                  m_ArchivedSetUpList.Add(Path.GetFileNameWithoutExtension(SetUpFileNames(FileIndex)))
+               End If
+            Next
+         End If
          ' Leggo attrezzaggio predefinito
          If EgtUILib.GetPrivateProfileString(S_SETUP, K_DEFAULT, "", MachOptionModule.m_sSelectedDefaultSetUp, IniFile.m_sCurrMachIniFilePath) <= 0 Then
             SelectedDefaultSetUp = Nothing
diff --git a/My Project/AssemblyInfo.vb b/My Project/AssemblyInfo.vb
index 7a11060..32dfd63 100644
--- a/My Project/AssemblyInfo.vb	
+++ b/My Project/AssemblyInfo.vb	
@@ -70,5 +70,5 @@ Imports System.Windows
 ' by using the '*' as shown below:
 ' <Assembly: AssemblyVersion("1.0.*")> 
 
-<Assembly: AssemblyVersion("1.9.2.1")> 
-<Assembly: AssemblyFileVersion("1.9.2.1")> 
+<Assembly: AssemblyVersion("1.9.3.1")> 
+<Assembly: AssemblyFileVersion("1.9.3.1")>