diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a594081..782c6eda 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ CHANGELOG for FlatCAM beta
 2.01.2021
 
 - removed the 'machinist setting' and allow all over the app the usages of both negative and positive values (where it is the case)
+- applied the changes from Andre Spahlinger from PR's #332 and #334
 
 31.12.2020
 
@@ -20,7 +21,7 @@ CHANGELOG for FlatCAM beta
 - fixed parseDXF() class imports to work with newer versions of ezdxf module (starting with 0.15) - contribution of Maurizio D'Addona and Hans Boot
 - fixed a string ("Penelization Reference") by Hans Boot contribution.
 - fixed a string ("Penelization Reference") translations by Hans Boot contribution.
-- fixed issue with not being able to mill holes in a Excellon object part of a loaded project (JSON serialization makes all keys in dictionary strings so I had to make sure that the obj.tools dict keys are made integers on project reconstruction)
+- fixed issue with not being able to mill holes in an Excellon object part of a loaded project (JSON serialization makes all keys in the dictionary into strings so I had to make sure that the obj.tools dict keys are made integers on project reconstruction)
 - added needed 'testresources' module in the setup_ubuntu.sh script - Hans Boot contribution
 
 30.12.2020
diff --git a/camlib.py b/camlib.py
index f28b4cf5..6d84971a 100644
--- a/camlib.py
+++ b/camlib.py
@@ -3104,6 +3104,8 @@ class CNCjob(Geometry):
         elif zcut == 0:
             self.app.inform.emit('[WARNING] %s.' % _("The Cut Z parameter is zero. There will be no cut, aborting"))
             return 'fail'
+        else:
+            return zcut
 
     # used in Tool Drilling
     def excellon_tool_gcode_gen(self, tool, points, tools, first_pt, is_first=False, is_last=False, opt_type='T',
diff --git a/tclCommands/TclCommandDrillcncjob.py b/tclCommands/TclCommandDrillcncjob.py
index efd90db4..40cb29c6 100644
--- a/tclCommands/TclCommandDrillcncjob.py
+++ b/tclCommands/TclCommandDrillcncjob.py
@@ -148,7 +148,7 @@ class TclCommandDrillcncjob(TclCommandSignaled):
                     req_tools = set()
                     for tool in obj.tools:
                         for req_dia in diameters:
-                            obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["C"])))
+                            obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["tooldia"])))
                             req_dia_form = float('%.*f' % (obj.decimals, float(req_dia)))
 
                             if 'diatol' in args:
@@ -157,11 +157,11 @@ class TclCommandDrillcncjob(TclCommandSignaled):
                                 tolerance = 0.0 if tolerance < 0.0 else tolerance
                                 tolerance = 1.0 if tolerance > 1.0 else tolerance
                                 if math.isclose(obj_dia_form, req_dia_form, rel_tol=tolerance):
-                                    req_tools.add(tool)
+                                    req_tools.add(str(tool))
                                     nr_diameters -= 1
                             else:
                                 if obj_dia_form == req_dia_form:
-                                    req_tools.add(tool)
+                                    req_tools.add(str(tool))
                                     nr_diameters -= 1
 
                     if nr_diameters > 0:
@@ -176,8 +176,9 @@ class TclCommandDrillcncjob(TclCommandSignaled):
                     tools = ','.join(req_tools)
 
                     # no longer needed
-                    del args['drilled_dias']
-                    del args['diatol']
+                    # del args['drilled_dias']
+                    args.pop('drilled_dias', None)
+                    args.pop('diatol', None)
 
                     # Split and put back. We are passing the whole dictionary later.
                     # args['milled_dias'] = [x.strip() for x in args['tools'].split(",")]
diff --git a/tclCommands/TclCommandMillDrills.py b/tclCommands/TclCommandMillDrills.py
index ece29c45..9c398925 100644
--- a/tclCommands/TclCommandMillDrills.py
+++ b/tclCommands/TclCommandMillDrills.py
@@ -104,7 +104,7 @@ class TclCommandMillDrills(TclCommandSignaled):
                 req_tools = set()
                 for tool in obj.tools:
                     for req_dia in diameters:
-                        obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["C"])))
+                        obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["tooldia"])))
                         req_dia_form = float('%.*f' % (obj.decimals, float(req_dia)))
 
                         if 'diatol' in args:
@@ -126,14 +126,14 @@ class TclCommandMillDrills(TclCommandSignaled):
 
                 args['tools'] = req_tools
 
-                # no longer needed
-                del args['milled_dias']
-                del args['diatol']
-
                 # Split and put back. We are passing the whole dictionary later.
                 # args['milled_dias'] = [x.strip() for x in args['tools'].split(",")]
             else:
                 args['tools'] = 'all'
+
+            # no longer needed
+            del args['milled_dias']
+            del args['diatol']
         except Exception as e:
             self.raise_tcl_error("Bad tools: %s" % str(e))