diff --git a/src/Mod/TechDraw/Gui/AppTechDrawGui.cpp b/src/Mod/TechDraw/Gui/AppTechDrawGui.cpp
index 98c264ac17..5f2978d8bb 100644
--- a/src/Mod/TechDraw/Gui/AppTechDrawGui.cpp
+++ b/src/Mod/TechDraw/Gui/AppTechDrawGui.cpp
@@ -75,6 +75,7 @@ void CreateTechDrawCommands(void);
 void CreateTechDrawCommandsDims(void);
 void CreateTechDrawCommandsDecorate(void);
 void CreateTechDrawCommandsAnnotate(void);
+void CreateTechDrawCommandsExtensions(void);
 
 void loadTechDrawResource()
 {
@@ -120,6 +121,7 @@ PyMOD_INIT_FUNC(TechDrawGui)
     CreateTechDrawCommandsDims();
     CreateTechDrawCommandsDecorate();
     CreateTechDrawCommandsAnnotate();
+    CreateTechDrawCommandsExtensions();
 
     TechDrawGui::Workbench::init();
     TechDrawGui::MDIViewPage::init();
diff --git a/src/Mod/TechDraw/Gui/CMakeLists.txt b/src/Mod/TechDraw/Gui/CMakeLists.txt
index 34de8ede6e..a8cfc77149 100644
--- a/src/Mod/TechDraw/Gui/CMakeLists.txt
+++ b/src/Mod/TechDraw/Gui/CMakeLists.txt
@@ -111,6 +111,7 @@ SET(TechDrawGui_SRCS
     CommandCreateDims.cpp
     CommandDecorate.cpp
     CommandAnnotate.cpp
+    CommandExtensionPack.cpp
     Resources/TechDraw.qrc
     PreCompiled.cpp
     PreCompiled.h
diff --git a/src/Mod/TechDraw/Gui/CommandExtensionPack.cpp b/src/Mod/TechDraw/Gui/CommandExtensionPack.cpp
new file mode 100644
index 0000000000..9ef6de7bf9
--- /dev/null
+++ b/src/Mod/TechDraw/Gui/CommandExtensionPack.cpp
@@ -0,0 +1,459 @@
+/***************************************************************************
+ *   Copyright (c) 2021 edi                                                *
+ *                                                                         *
+ *   This file is part of the FreeCAD CAx development system.              *
+ *                                                                         *
+ *   This library is free software; you can redistribute it and/or         *
+ *   modify it under the terms of the GNU Library General Public           *
+ *   License as published by the Free Software Foundation; either          *
+ *   version 2 of the License, or (at your option) any later version.      *
+ *                                                                         *
+ *   This library  is distributed in the hope that it will be useful,      *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU Library General Public License for more details.                  *
+ *                                                                         *
+ *   You should have received a copy of the GNU Library General Public     *
+ *   License along with this library; see the file COPYING.LIB. If not,    *
+ *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
+ *   Suite 330, Boston, MA  02111-1307, USA                                *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "PreCompiled.h"
+#ifndef _PreComp_
+# include <QMessageBox>
+# include <iostream>
+# include <string>
+# include <sstream>
+# include <cstdlib>
+# include <exception>
+#endif  //#ifndef _PreComp_
+
+#include <QGraphicsView>
+
+# include <App/DocumentObject.h>
+# include <Base/Exception.h>
+#include <Base/Console.h>
+#include <Base/Type.h>
+# include <Gui/Action.h>
+# include <Gui/Application.h>
+# include <Gui/BitmapFactory.h>
+# include <Gui/Command.h>
+# include <Gui/Control.h>
+# include <Gui/Document.h>
+# include <Gui/Selection.h>
+# include <Gui/MainWindow.h>
+# include <Gui/FileDialog.h>
+# include <Gui/ViewProvider.h>
+
+# include <Mod/Part/App/PartFeature.h>
+
+# include <Mod/TechDraw/App/DrawViewPart.h>
+# include <Mod/TechDraw/App/DrawProjGroupItem.h>
+# include <Mod/TechDraw/App/DrawProjGroup.h>
+# include <Mod/TechDraw/App/DrawViewDimension.h>
+# include <Mod/TechDraw/App/DrawDimHelper.h>
+# include <Mod/TechDraw/App/LandmarkDimension.h>
+# include <Mod/TechDraw/App/DrawPage.h>
+# include <Mod/TechDraw/App/DrawUtil.h>
+# include <Mod/TechDraw/App/Geometry.h>
+
+#include <Mod/TechDraw/Gui/QGVPage.h>
+
+
+#include "DrawGuiUtil.h"
+#include "MDIViewPage.h"
+#include "ViewProviderPage.h"
+#include "TaskLinkDim.h"
+
+using namespace TechDrawGui;
+using namespace TechDraw;
+using namespace std;
+
+//internal helper functions
+bool _circulation(Base::Vector3d A, Base::Vector3d B, Base::Vector3d C);
+void _createThreadCircle(std::string Name, TechDraw::DrawViewPart* objFeat, float factor);
+void _createThreadLines(std::vector<std::string> SubNames, TechDraw::DrawViewPart* objFeat, float factor);
+void _setStyleAndWeight(TechDraw::CosmeticEdge* cosEdge, int style, float weight);
+
+//===========================================================================
+// TechDraw_ExtensionCircleCenterLines
+//===========================================================================
+
+DEF_STD_CMD_A(CmdTechDrawExtensionCircleCenterLines)
+
+CmdTechDrawExtensionCircleCenterLines::CmdTechDrawExtensionCircleCenterLines()
+  : Command("TechDraw_ExtensionCircleCenterLines")
+{
+    sAppModule      = "TechDraw";
+    sGroup          = QT_TR_NOOP("TechDraw");
+    sMenuText       = QT_TR_NOOP("Draw circle center lines");
+    sToolTipText    = QT_TR_NOOP("Draw circle center line cross at circles\n\
+    - select many circles or arcs\n\
+    - click this button");
+    sWhatsThis      = "TechDraw_ExtensionCircleCenterLines";
+    sStatusTip      = sToolTipText;
+    sPixmap         = "TechDraw_ExtensionCircleCenterLines";
+}
+
+void CmdTechDrawExtensionCircleCenterLines::activated(int iMsg)
+{
+    Q_UNUSED(iMsg);
+    auto selection = getSelection().getSelectionEx();
+    if( selection.empty() ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Circle Centerlines"),
+                             QObject::tr("Selection is empty"));
+        return;
+    }
+    auto objFeat = dynamic_cast<TechDraw::DrawViewPart *>(selection[0].getObject());
+    if( objFeat == nullptr ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Circle Centerlines"),
+                             QObject::tr("No object selected"));
+        return;
+    }
+    double scale = objFeat->getScale();
+    const std::vector<std::string> SubNames = selection[0].getSubNames();
+    for (std::string Name : SubNames) {
+        int GeoId = TechDraw::DrawUtil::getIndexFromName(Name);
+        TechDraw::BaseGeom* geom = objFeat->getGeomByIndex(GeoId);
+        std::string GeoType = TechDraw::DrawUtil::getGeomTypeFromName(Name);
+        if (GeoType == "Edge"){
+            if (geom->geomType == TechDraw::CIRCLE ||
+                geom->geomType == TechDraw::ARCOFCIRCLE){
+                TechDraw::Circle* cgen = static_cast<TechDraw::Circle *>(geom);
+                Base::Vector3d center = cgen->center;
+                center.y = -center.y;
+                float radius = cgen->radius;
+                Base::Vector3d right(center.x+radius+2.0,center.y,0.0);
+                Base::Vector3d top(center.x,center.y+radius+2.0,0.0);
+                Base::Vector3d left(center.x-radius-2.0,center.y,0.0);
+                Base::Vector3d bottom(center.x,center.y-radius-2.0,0.0);
+                std::string line1tag = objFeat->addCosmeticEdge(right/scale, left/scale);
+                std::string line2tag = objFeat->addCosmeticEdge(top/scale, bottom/scale);
+                TechDraw::CosmeticEdge* horiz = objFeat->getCosmeticEdge(line1tag);
+                _setStyleAndWeight(horiz,4,0.35);
+                TechDraw::CosmeticEdge* vert = objFeat->getCosmeticEdge(line2tag);
+                _setStyleAndWeight(vert,4,0.35);
+            }
+        }
+    }
+    getSelection().clearSelection();
+    objFeat->refreshCEGeoms();
+    objFeat->requestPaint();
+}
+
+bool CmdTechDrawExtensionCircleCenterLines::isActive(void)
+{
+    bool havePage = DrawGuiUtil::needPage(this);
+    bool haveView = DrawGuiUtil::needView(this);
+    return (havePage && haveView);
+}
+
+//===========================================================================
+// TechDraw_ExtensionThreadHoleSide
+//===========================================================================
+
+DEF_STD_CMD_A(CmdTechDrawExtensionThreadHoleSide)
+
+CmdTechDrawExtensionThreadHoleSide::CmdTechDrawExtensionThreadHoleSide()
+  : Command("TechDraw_ExtensionThreadHoleSide")
+{
+    sAppModule      = "TechDraw";
+    sGroup          = QT_TR_NOOP("TechDraw");
+    sMenuText       = QT_TR_NOOP("Cosmetic thread hole side view");
+    sToolTipText    = QT_TR_NOOP("Draw cosmetic thread hole side view\n\
+    - select two parallel lines\n\
+    - click this button");
+    sWhatsThis      = "TechDraw_ExtensionThreadHoleSide";
+    sStatusTip      = sToolTipText;
+    sPixmap         = "TechDraw_ExtensionThreadHoleSide";
+}
+
+void CmdTechDrawExtensionThreadHoleSide::activated(int iMsg)
+{
+    Q_UNUSED(iMsg);
+    auto selection = getSelection().getSelectionEx();
+    if( selection.empty() ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Hole Side"),
+                             QObject::tr("Selection is empty"));
+        return;
+    }
+    TechDraw::DrawViewPart* objFeat = dynamic_cast<TechDraw::DrawViewPart *>(selection[0].getObject());
+    if( objFeat == nullptr ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Hole Side"),
+                             QObject::tr("No object selected"));
+        return;
+    }
+    const std::vector<std::string> SubNames = selection[0].getSubNames();
+    if (SubNames.size() >= 2) {
+        _createThreadLines(SubNames, objFeat, 1.176);
+    }
+    getSelection().clearSelection();
+    objFeat->refreshCEGeoms();
+    objFeat->requestPaint();
+}
+
+bool CmdTechDrawExtensionThreadHoleSide::isActive(void)
+{
+    bool havePage = DrawGuiUtil::needPage(this);
+    bool haveView = DrawGuiUtil::needView(this);
+    return (havePage && haveView);
+}
+
+//===========================================================================
+// TechDraw_ExtensionThreadBoltSide
+//===========================================================================
+
+DEF_STD_CMD_A(CmdTechDrawExtensionThreadBoltSide)
+
+CmdTechDrawExtensionThreadBoltSide::CmdTechDrawExtensionThreadBoltSide()
+  : Command("TechDraw_ExtensionThreadBoltSide")
+{
+    sAppModule      = "TechDraw";
+    sGroup          = QT_TR_NOOP("TechDraw");
+    sMenuText       = QT_TR_NOOP("Cosmetic thread bolt side view");
+    sToolTipText    = QT_TR_NOOP("Draw cosmetic screw thread side view\n\
+    - select two parallel lines\n\
+    - click this button");
+    sWhatsThis      = "TechDraw_ExtensionThreadBoltSide";
+    sStatusTip      = sToolTipText;
+    sPixmap         = "TechDraw_ExtensionThreadBoltSide";
+}
+
+void CmdTechDrawExtensionThreadBoltSide::activated(int iMsg)
+{
+    Q_UNUSED(iMsg);
+    auto selection = getSelection().getSelectionEx();
+    if( selection.empty() ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Bolt Side"),
+                             QObject::tr("Selection is empty"));
+        return;
+    }
+    TechDraw::DrawViewPart* objFeat = dynamic_cast<TechDraw::DrawViewPart *>(selection[0].getObject());
+    if( objFeat == nullptr ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Bolt Side"),
+                             QObject::tr("No object selected"));
+        return;
+    }
+    const std::vector<std::string> SubNames = selection[0].getSubNames();
+    if (SubNames.size() >= 2) {
+        _createThreadLines(SubNames, objFeat, 0.85);
+    }
+    getSelection().clearSelection();
+    objFeat->refreshCEGeoms();
+    objFeat->requestPaint();
+}
+
+bool CmdTechDrawExtensionThreadBoltSide::isActive(void)
+{
+    bool havePage = DrawGuiUtil::needPage(this);
+    bool haveView = DrawGuiUtil::needView(this);
+    return (havePage && haveView);
+}
+
+//===========================================================================
+// TechDraw_ExtensionThreadHoleBottom
+//===========================================================================
+
+DEF_STD_CMD_A(CmdTechDrawExtensionThreadHoleBottom)
+
+CmdTechDrawExtensionThreadHoleBottom::CmdTechDrawExtensionThreadHoleBottom()
+  : Command("TechDraw_ExtensionThreadHoleBottom")
+{
+    sAppModule      = "TechDraw";
+    sGroup          = QT_TR_NOOP("TechDraw");
+    sMenuText       = QT_TR_NOOP("Cosmetic thread hole bottom view");
+    sToolTipText    = QT_TR_NOOP("Draw cosmetic hole thread ground view\n\
+    - select many circles\n\
+    - click this button");
+    sWhatsThis      = "TechDraw_ExtensionThreadHoleBottom";
+    sStatusTip      = sToolTipText;
+    sPixmap         = "TechDraw_ExtensionThreadHoleBottom";
+}
+
+void CmdTechDrawExtensionThreadHoleBottom::activated(int iMsg)
+{
+    Q_UNUSED(iMsg);
+    auto selection = getSelection().getSelectionEx();
+    if( selection.empty() ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Hole Bottom"),
+                             QObject::tr("Selection is empty"));
+        return;
+    }
+    auto objFeat = dynamic_cast<TechDraw::DrawViewPart *>(selection[0].getObject());
+    if( objFeat == nullptr ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Thread Hole Bottom"),
+                             QObject::tr("No object selected"));
+        return;
+    }
+    const std::vector<std::string> SubNames = selection[0].getSubNames();
+    for (std::string Name : SubNames) {
+        _createThreadCircle(Name, objFeat, 1.177);
+    }
+    getSelection().clearSelection();
+    objFeat->refreshCEGeoms();
+    objFeat->requestPaint();
+}
+
+bool CmdTechDrawExtensionThreadHoleBottom::isActive(void)
+{
+    bool havePage = DrawGuiUtil::needPage(this);
+    bool haveView = DrawGuiUtil::needView(this);
+    return (havePage && haveView);
+}
+
+//===========================================================================
+// TechDraw_ExtensionThreadBoltBottom
+//===========================================================================
+
+DEF_STD_CMD_A(CmdTechDrawExtensionThreadBoltBottom)
+
+CmdTechDrawExtensionThreadBoltBottom::CmdTechDrawExtensionThreadBoltBottom()
+  : Command("TechDraw_ExtensionThreadBoltBottom")
+{
+    sAppModule      = "TechDraw";
+    sGroup          = QT_TR_NOOP("TechDraw");
+    sMenuText       = QT_TR_NOOP("Cosmetic thread bolt bottom view");
+    sToolTipText    = QT_TR_NOOP("Draw cosmetic screw thread ground view\n\
+    - select many circles\n\
+    - click this button");
+    sWhatsThis      = "TechDraw_ExtensionThreadBoltBottom";
+    sStatusTip      = sToolTipText;
+    sPixmap         = "TechDraw_ExtensionThreadBoltBottom";
+}
+
+void CmdTechDrawExtensionThreadBoltBottom::activated(int iMsg)
+{
+    Q_UNUSED(iMsg);
+    auto selection = getSelection().getSelectionEx();
+    if( selection.empty() ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Tread Bolt Bottom"),
+                             QObject::tr("Selection is empty"));
+        return;
+    }
+    auto objFeat = dynamic_cast<TechDraw::DrawViewPart *>(selection[0].getObject());
+    if( objFeat == nullptr ) {
+        QMessageBox::warning(Gui::getMainWindow(),
+                             QObject::tr("TechDraw Tread Bolt Bottom"),
+                             QObject::tr("No object selected"));
+        return;
+    }
+    const std::vector<std::string> SubNames = selection[0].getSubNames();
+    for (std::string Name : SubNames) {
+        _createThreadCircle(Name, objFeat, 0.85);
+    }
+    getSelection().clearSelection();
+    objFeat->refreshCEGeoms();
+    objFeat->requestPaint();
+}
+
+bool CmdTechDrawExtensionThreadBoltBottom::isActive(void)
+{
+    bool havePage = DrawGuiUtil::needPage(this);
+    bool haveView = DrawGuiUtil::needView(this);
+    return (havePage && haveView);
+}
+
+//===========================================================================
+// internal helper routines
+//===========================================================================
+
+bool _circulation(Base::Vector3d A, Base::Vector3d B, Base::Vector3d C){
+    // test the circulation of the triangle A-B-C
+    if (A.x*B.y+A.y*C.x+B.x*C.y-C.x*B.y-C.y*A.x-B.x*A.y > 0.0)
+        return true;
+    else
+        return false;
+}
+
+void _createThreadCircle(std::string Name, TechDraw::DrawViewPart* objFeat, float factor){
+    // create the 3/4 arc symbolizing a thread from top seen
+    double scale = objFeat->getScale();
+    int GeoId = TechDraw::DrawUtil::getIndexFromName(Name);
+    TechDraw::BaseGeom* geom = objFeat->getGeomByIndex(GeoId);
+    std::string GeoType = TechDraw::DrawUtil::getGeomTypeFromName(Name);
+    if (GeoType == "Edge"){
+        if (geom->geomType == TechDraw::CIRCLE){
+            TechDraw::Circle* cgen = static_cast<TechDraw::Circle *>(geom);
+            Base::Vector3d center = cgen->center;
+            float radius = cgen->radius;
+            TechDraw::BaseGeom* threadArc = new TechDraw::AOC(center/scale, radius*factor/scale, 255.0, 165.0);
+            std::string arcTag = objFeat->addCosmeticEdge(threadArc);
+            TechDraw::CosmeticEdge* arc = objFeat->getCosmeticEdge(arcTag);
+            _setStyleAndWeight(arc,1,0.35);
+        }
+    }
+}
+
+void _createThreadLines(std::vector<std::string> SubNames, TechDraw::DrawViewPart* objFeat, float factor){
+    // create symbolizing lines of a thread from the side seen
+    double scale = objFeat->getScale();
+    std::string GeoType0 = TechDraw::DrawUtil::getGeomTypeFromName(SubNames[0]);
+    std::string GeoType1 = TechDraw::DrawUtil::getGeomTypeFromName(SubNames[1]);
+    if ((GeoType0 == "Edge") && (GeoType1 == "Edge")) {
+        int GeoId0 = TechDraw::DrawUtil::getIndexFromName(SubNames[0]);
+        int GeoId1 = TechDraw::DrawUtil::getIndexFromName(SubNames[1]);
+        TechDraw::BaseGeom* geom0 = objFeat->getGeomByIndex(GeoId0);
+        TechDraw::BaseGeom* geom1 = objFeat->getGeomByIndex(GeoId1);
+        if ((geom0->geomType == TechDraw::GENERIC) && (geom1->geomType == TechDraw::GENERIC)) {
+            TechDraw::Generic* line0 = static_cast<TechDraw::Generic *>(geom0);
+            TechDraw::Generic* line1 = static_cast<TechDraw::Generic *>(geom1);
+            Base::Vector3d start0 = line0->points.at(0);
+            Base::Vector3d end0 = line0->points.at(1);
+            Base::Vector3d start1 = line1->points.at(0);
+            Base::Vector3d end1 = line1->points.at(1);
+            if (_circulation(start0,end0,start1) != _circulation(end0,end1,start1)) {
+                Base::Vector3d help1 = start1;
+                Base::Vector3d help2 = end1;
+                start1 = help2;
+                end1 = help1;
+            }
+            start0.y = -start0.y;
+            end0.y = -end0.y;
+            start1.y = -start1.y;
+            end1.y = -end1.y;
+            float kernelDiam = (start1-start0).Length();
+            float kernelFactor = (kernelDiam*factor-kernelDiam)/2;
+            Base::Vector3d delta = (start1-start0).Normalize()*kernelFactor;
+            std::string line0Tag = objFeat->addCosmeticEdge((start0-delta)/scale, (end0-delta)/scale);
+            std::string line1Tag = objFeat->addCosmeticEdge((start1+delta)/scale, (end1+delta)/scale);
+            TechDraw::CosmeticEdge* cosTag0 = objFeat->getCosmeticEdge(line0Tag);
+            TechDraw::CosmeticEdge* cosTag1 = objFeat->getCosmeticEdge(line1Tag);
+            _setStyleAndWeight(cosTag0,1,0.35);
+            _setStyleAndWeight(cosTag1,1,0.35);
+        } else {
+            QMessageBox::warning(Gui::getMainWindow(),
+                                 QObject::tr("TechDraw Thread Hole Side"),
+                                 QObject::tr("Please select two straight lines"));
+            return;
+        }
+    }
+}
+
+void _setStyleAndWeight(TechDraw::CosmeticEdge* cosEdge, int style, float weight) {
+    // set style and weight of a cosmetic edge
+    cosEdge->m_format.m_style = style;
+    cosEdge->m_format.m_weight = weight;
+}
+
+//------------------------------------------------------------------------------
+void CreateTechDrawCommandsExtensions(void)
+{
+    Gui::CommandManager &rcCmdMgr = Gui::Application::Instance->commandManager();
+
+    rcCmdMgr.addCommand(new CmdTechDrawExtensionCircleCenterLines());
+    rcCmdMgr.addCommand(new CmdTechDrawExtensionThreadHoleSide());
+    rcCmdMgr.addCommand(new CmdTechDrawExtensionThreadBoltSide());
+    rcCmdMgr.addCommand(new CmdTechDrawExtensionThreadHoleBottom());
+    rcCmdMgr.addCommand(new CmdTechDrawExtensionThreadBoltBottom());
+}
diff --git a/src/Mod/TechDraw/Gui/Resources/TechDraw.qrc b/src/Mod/TechDraw/Gui/Resources/TechDraw.qrc
index 919a00d855..ebc5c28142 100644
--- a/src/Mod/TechDraw/Gui/Resources/TechDraw.qrc
+++ b/src/Mod/TechDraw/Gui/Resources/TechDraw.qrc
@@ -27,6 +27,11 @@
         <file>icons/TechDraw_3PtAngleDimension.svg</file>
         <file>icons/TechDraw_DiameterDimension.svg</file>
         <file>icons/TechDraw_HorizontalDimension.svg</file>
+        <file>icons/TechDraw_ExtensionCircleCenterLines.svg</file>
+        <file>icons/TechDraw_ExtensionThreadHoleSide.svg</file>
+        <file>icons/TechDraw_ExtensionThreadBoltSide.svg</file>
+        <file>icons/TechDraw_ExtensionThreadHoleBottom.svg</file>
+        <file>icons/TechDraw_ExtensionThreadBoltBottom.svg</file>
         <file>icons/TechDraw_LengthDimension.svg</file>
         <file>icons/TechDraw_RadiusDimension.svg</file>
         <file>icons/TechDraw_Balloon.svg</file>
diff --git a/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionCircleCenterLines.svg b/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionCircleCenterLines.svg
new file mode 100644
index 0000000000..ab8b110c4b
--- /dev/null
+++ b/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionCircleCenterLines.svg
@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:osb="http://www.openswatchbook.org/uri/2009/osb"
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="64"
+   height="64"
+   viewBox="0 0 16.933333 16.933334"
+   version="1.1"
+   id="svg8"
+   inkscape:version="0.92.2 (5c3e80d, 2017-08-06)"
+   sodipodi:docname="assi_mezzerie_giallo.svg">
+  <defs
+     id="defs2">
+    <linearGradient
+       id="linearGradient5969"
+       osb:paint="solid">
+      <stop
+         style="stop-color:#000000;stop-opacity:1;"
+         offset="0"
+         id="stop5967" />
+    </linearGradient>
+  </defs>
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="5.6"
+     inkscape:cx="28.547192"
+     inkscape:cy="30.303061"
+     inkscape:document-units="mm"
+     inkscape:current-layer="layer1"
+     showgrid="false"
+     units="px"
+     inkscape:pagecheckerboard="true"
+     inkscape:window-width="1366"
+     inkscape:window-height="745"
+     inkscape:window-x="-8"
+     inkscape:window-y="-8"
+     inkscape:window-maximized="1" />
+  <metadata
+     id="metadata5">
+    <rdf:RDF>
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diff --git a/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionThreadHoleSide.svg b/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionThreadHoleSide.svg
new file mode 100644
index 0000000000..bc976b0627
--- /dev/null
+++ b/src/Mod/TechDraw/Gui/Resources/icons/TechDraw_ExtensionThreadHoleSide.svg
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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+   xmlns:dc="http://purl.org/dc/elements/1.1/"
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+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
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+      <cc:Work
+         rdf:about="">
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+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
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+  </g>
+</svg>
diff --git a/src/Mod/TechDraw/Gui/Workbench.cpp b/src/Mod/TechDraw/Gui/Workbench.cpp
index ec8cda8e06..99e1a81aaa 100644
--- a/src/Mod/TechDraw/Gui/Workbench.cpp
+++ b/src/Mod/TechDraw/Gui/Workbench.cpp
@@ -80,6 +80,15 @@ Gui::MenuItem* Workbench::setupMenuBar() const
     *dimensions << "TechDraw_LinkDimension";
     *dimensions << "TechDraw_LandmarkDimension";
 
+    // toolattributes
+    Gui::MenuItem* toolattrib = new Gui::MenuItem;
+    toolattrib->setCommand("Extensions: centerlines and threading");
+    *toolattrib << "TechDraw_ExtensionCircleCenterLines";
+    *toolattrib << "TechDraw_ExtensionThreadHoleSide";
+    *toolattrib << "TechDraw_ExtensionThreadBoltSide";
+    *toolattrib << "TechDraw_ExtensionThreadHoleBottom";
+    *toolattrib << "TechDraw_ExtensionThreadBoltBottom";
+
     // annotations
     Gui::MenuItem* annotations = new Gui::MenuItem;
     annotations->setCommand("Annotations");
@@ -124,6 +133,7 @@ Gui::MenuItem* Workbench::setupMenuBar() const
     *draw << "TechDraw_ClipGroupRemove";
     *draw << "Separator";
     *draw << dimensions;
+    *draw << toolattrib;
     *draw << "Separator";
     *draw << "TechDraw_ExportPageSVG";
     *draw << "TechDraw_ExportPageDXF";
@@ -187,6 +197,14 @@ Gui::ToolBarItem* Workbench::setupToolBars() const
     *dims << "TechDraw_LandmarkDimension";
 //    *dims << "TechDraw_Dimension"
 
+    Gui::ToolBarItem *attribs = new Gui::ToolBarItem(root);
+    attribs->setCommand("TechDraw Toolattributes");
+    *attribs << "TechDraw_ExtensionCircleCenterLines";
+    *attribs << "TechDraw_ExtensionThreadHoleSide";
+    *attribs << "TechDraw_ExtensionThreadBoltSide";
+    *attribs << "TechDraw_ExtensionThreadHoleBottom";
+    *attribs << "TechDraw_ExtensionThreadBoltBottom";
+
     Gui::ToolBarItem *file = new Gui::ToolBarItem(root);
     file->setCommand("TechDraw File Access");
     *file << "TechDraw_ExportPageSVG";
@@ -261,6 +279,15 @@ Gui::ToolBarItem* Workbench::setupCommandBars() const
     *dims << "TechDraw_LandmarkDimension";
 //    *dims << "TechDraw_Dimension";
 
+    Gui::ToolBarItem *attribs = new Gui::ToolBarItem(root);
+    attribs->setCommand("TechDraw Toolattributes");
+    *attribs << "TechDraw_ExtensionCircleCenterLines";
+    *attribs << "TechDraw_ExtensionThreadHoleSide";
+    *attribs << "TechDraw_ExtensionThreadBoltSide";
+    *attribs << "TechDraw_ExtensionThreadHoleBottom";
+    *attribs << "TechDraw_ExtensionThreadBoltBottom";
+
+
     Gui::ToolBarItem *file = new Gui::ToolBarItem(root);
     file->setCommand("TechDraw File Access");
     *file << "TechDraw_ExportPageSVG";