diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFixed.cpp b/src/Mod/Fem/Gui/TaskFemConstraintFixed.cpp
index d35fbd6af0..9e64dddb45 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFixed.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFixed.cpp
@@ -60,7 +60,7 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintFixed */
 
 TaskFemConstraintFixed::TaskFemConstraintFixed(ViewProviderFemConstraintFixed *ConstraintView,QWidget *parent)
-  : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintFixed")
+  : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintFixed")
 { //Note change "Fixed" in line above to new constraint name
     proxy = new QWidget(this);
     ui = new Ui_TaskFemConstraintFixed();
@@ -96,8 +96,10 @@ TaskFemConstraintFixed::TaskFemConstraintFixed(ViewProviderFemConstraintFixed *C
     }
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()),  this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()),  this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     updateUI();
 }
@@ -244,6 +246,12 @@ void TaskFemConstraintFixed::changeEvent(QEvent *)
 {
 }
 
+void TaskFemConstraintFixed::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 // TaskDialog
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFixed.h b/src/Mod/Fem/Gui/TaskFemConstraintFixed.h
index 1660de7403..2ab61aac72 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFixed.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFixed.h
@@ -31,6 +31,7 @@
 #include <Base/Quantity.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintFixed.h"
 
 #include <QObject>
@@ -40,7 +41,7 @@
 class Ui_TaskFemConstraintFixed;
 
 namespace FemGui {
-class TaskFemConstraintFixed : public TaskFemConstraint
+class TaskFemConstraintFixed : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -57,6 +58,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFixed.ui b/src/Mod/Fem/Gui/TaskFemConstraintFixed.ui
index 27162f1410..2ded773f6f 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFixed.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFixed.ui
@@ -24,17 +24,23 @@
    <item>
     <layout class="QHBoxLayout" name="hLayout1">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.cpp b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.cpp
index 2146270d2f..17d182b96a 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.cpp
@@ -132,7 +132,7 @@ void initComboBox(QComboBox* combo, const std::vector<std::string>& textItems, c
 
 /* TRANSLATOR FemGui::TaskFemConstraintFluidBoundary */
 TaskFemConstraintFluidBoundary::TaskFemConstraintFluidBoundary(ViewProviderFemConstraintFluidBoundary *ConstraintView,QWidget *parent)
-    : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintFluidBoundary")
+    : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintFluidBoundary")
     , dimension(-1)
 {
     // we need a separate container widget to add all controls to
@@ -175,8 +175,10 @@ TaskFemConstraintFluidBoundary::TaskFemConstraintFluidBoundary(ViewProviderFemCo
     ui->checkReverse->blockSignals(true);
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()), this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()), this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     // Get the feature data
     Fem::ConstraintFluidBoundary* pcConstraint = static_cast<Fem::ConstraintFluidBoundary*>(ConstraintView->getObject());
@@ -557,6 +559,9 @@ void TaskFemConstraintFluidBoundary::onButtonDirection(const bool pressed)
     // sets the normal vector of the currently selecteed planar face as direction
 
     Q_UNUSED(pressed)
+
+    clearButtons(none);
+
     //get vector of selected objects of active document
     std::vector<Gui::SelectionObject> selection = Gui::Selection().getSelectionEx();
     if (selection.size() == 0) {
@@ -863,6 +868,12 @@ void TaskFemConstraintFluidBoundary::changeEvent(QEvent *e)
     }
 }
 
+void TaskFemConstraintFluidBoundary::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 //**************************************************************************
 // TaskDialog
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.h b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.h
index d388a92954..9c0036a246 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.h
@@ -31,6 +31,7 @@
 #include <Mod/Fem/App/FemSolverObject.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintFluidBoundary.h"
 
 #include <QKeyEvent>
@@ -47,7 +48,7 @@ class ViewProvider;
 
 namespace FemGui {
 
-class TaskFemConstraintFluidBoundary : public TaskFemConstraint
+class TaskFemConstraintFluidBoundary : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -92,6 +93,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     virtual void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateBoundaryTypeUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.ui b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.ui
index 68f0af5b3a..ab044095d2 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintFluidBoundary.ui
@@ -88,17 +88,23 @@
      <item>
       <layout class="QHBoxLayout" name="horizontalLayout_2">
        <item>
-        <widget class="QPushButton" name="btnAdd">
+        <widget class="QToolButton" name="btnAdd">
          <property name="text">
           <string>Add</string>
          </property>
+         <property name="checkable">
+           <bool>true</bool>
+         </property>
         </widget>
        </item>
        <item>
-        <widget class="QPushButton" name="btnRemove">
+        <widget class="QToolButton" name="btnRemove">
          <property name="text">
           <string>Remove</string>
          </property>
+         <property name="checkable">
+           <bool>true</bool>
+         </property>
         </widget>
        </item>
       </layout>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintForce.cpp b/src/Mod/Fem/Gui/TaskFemConstraintForce.cpp
index 83e4986e19..014aaff8ea 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintForce.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintForce.cpp
@@ -70,7 +70,7 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintForce */
 
 TaskFemConstraintForce::TaskFemConstraintForce(ViewProviderFemConstraintForce *ConstraintView,QWidget *parent)
-    : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintForce")
+    : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintForce")
 {
     // we need a separate container widget to add all controls to
     proxy = new QWidget(this);
@@ -128,8 +128,10 @@ TaskFemConstraintForce::TaskFemConstraintForce(ViewProviderFemConstraintForce *C
     ui->checkReverse->blockSignals(false);
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()), this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()), this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     updateUI();
 }
@@ -315,6 +317,8 @@ void TaskFemConstraintForce::onButtonDirection(const bool pressed)
     // sets the normal vector of the currently selecteed planar face as direction
     Q_UNUSED(pressed)
 
+    clearButtons(none);
+
     auto link = getDirection(Gui::Selection().getSelectionEx());
     if (!link.first) {
         QMessageBox::warning(this, tr("Wrong selection"), tr("Select an edge or a face, please."));
@@ -402,6 +406,12 @@ void TaskFemConstraintForce::changeEvent(QEvent *e)
     }
 }
 
+void TaskFemConstraintForce::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 //**************************************************************************
 // TaskDialog
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintForce.h b/src/Mod/Fem/Gui/TaskFemConstraintForce.h
index 893bb76364..5e56d2077e 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintForce.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintForce.h
@@ -30,6 +30,7 @@
 #include <Gui/TaskView/TaskDialog.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintForce.h"
 
 #include <QKeyEvent>
@@ -47,7 +48,7 @@ class ViewProvider;
 
 namespace FemGui {
 
-class TaskFemConstraintForce : public TaskFemConstraint
+class TaskFemConstraintForce : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -71,6 +72,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     virtual void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     std::pair<App::DocumentObject*, std::string> getDirection(const std::vector<Gui::SelectionObject>&) const;
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintForce.ui b/src/Mod/Fem/Gui/TaskFemConstraintForce.ui
index 047b5e9275..7ae0e5fbd0 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintForce.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintForce.ui
@@ -42,17 +42,23 @@
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>
@@ -94,7 +100,7 @@
    <item>
     <layout class="QHBoxLayout" name="layoutDirection">
      <item>
-      <widget class="QPushButton" name="buttonDirection">
+      <widget class="QToolButton" name="buttonDirection">
        <property name="toolTip">
         <string>Select a planar edge or face, then press this button</string>
        </property>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.cpp b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.cpp
index 90475d3151..7a853192c4 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.cpp
@@ -59,7 +59,7 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintHeatflux */
 
 TaskFemConstraintHeatflux::TaskFemConstraintHeatflux(ViewProviderFemConstraintHeatflux *ConstraintView,QWidget *parent)
-  : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintHeatflux")
+  : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintHeatflux")
 {
     proxy = new QWidget(this);
     ui = new Ui_TaskFemConstraintHeatflux();
@@ -130,8 +130,10 @@ TaskFemConstraintHeatflux::TaskFemConstraintHeatflux(ViewProviderFemConstraintHe
     }
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()),  this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()),  this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     ui->if_ambienttemp->blockSignals(false);
     //ui->if_facetemp->blockSignals(false);
@@ -375,6 +377,12 @@ void TaskFemConstraintHeatflux::changeEvent(QEvent *e)
     }
 }
 
+void TaskFemConstraintHeatflux::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 // TaskDialog
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.h b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.h
index 272528b5a8..5d26530d4d 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.h
@@ -33,6 +33,7 @@
 #include <Base/Quantity.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintHeatflux.h"
 
 #include <QObject>
@@ -43,7 +44,7 @@
 class Ui_TaskFemConstraintHeatflux;
 
 namespace FemGui {
-class TaskFemConstraintHeatflux : public TaskFemConstraint
+class TaskFemConstraintHeatflux : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -70,6 +71,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     virtual void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.ui b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.ui
index 7c78b140af..0fa4fdeeb2 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintHeatflux.ui
@@ -24,17 +24,23 @@
    <item>
     <layout class="QHBoxLayout" name="hLayout1">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintPressure.cpp b/src/Mod/Fem/Gui/TaskFemConstraintPressure.cpp
index 776e04fa5e..a8a7621793 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintPressure.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintPressure.cpp
@@ -59,7 +59,7 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintPressure */
 
 TaskFemConstraintPressure::TaskFemConstraintPressure(ViewProviderFemConstraintPressure *ConstraintView,QWidget *parent)
-  : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintPressure")
+    : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintPressure")
 { //Note change "pressure" in line above to new constraint name
     proxy = new QWidget(this);
     ui = new Ui_TaskFemConstraintPressure();
@@ -105,8 +105,10 @@ TaskFemConstraintPressure::TaskFemConstraintPressure(ViewProviderFemConstraintPr
     }
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()),  this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()),  this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     updateUI();
 }
@@ -261,6 +263,12 @@ void TaskFemConstraintPressure::changeEvent(QEvent *)
 {
 }
 
+void TaskFemConstraintPressure::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 // TaskDialog
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintPressure.h b/src/Mod/Fem/Gui/TaskFemConstraintPressure.h
index 0fb3efee63..6088d0f961 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintPressure.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintPressure.h
@@ -33,6 +33,7 @@
 #include <Base/Quantity.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintPressure.h"
 
 #include <QObject>
@@ -43,7 +44,7 @@
 class Ui_TaskFemConstraintPressure;
 
 namespace FemGui {
-class TaskFemConstraintPressure : public TaskFemConstraint
+class TaskFemConstraintPressure : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -63,6 +64,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintPressure.ui b/src/Mod/Fem/Gui/TaskFemConstraintPressure.ui
index 844fe15dd6..ceb96b4737 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintPressure.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintPressure.ui
@@ -24,17 +24,23 @@
    <item>
     <layout class="QHBoxLayout" name="hLayout1">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintSpring.cpp b/src/Mod/Fem/Gui/TaskFemConstraintSpring.cpp
index 005b56c591..3fea6102b6 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintSpring.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintSpring.cpp
@@ -59,8 +59,8 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintSpring */
 
 TaskFemConstraintSpring::TaskFemConstraintSpring(ViewProviderFemConstraintSpring *ConstraintView, QWidget *parent)
-  : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintSpring")
-{ 
+  : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintSpring")
+{
     proxy = new QWidget(this);
     ui = new Ui_TaskFemConstraintSpring();
     ui->setupUi(proxy);
@@ -95,7 +95,7 @@ TaskFemConstraintSpring::TaskFemConstraintSpring(ViewProviderFemConstraintSpring
     ui->if_tan->setMaximum(FLOAT_MAX);
     Base::Quantity ts = Base::Quantity((pcConstraint->tangentialStiffness.getValue()), Base::Unit::Stiffness);
     ui->if_tan->setValue(ts);
-    
+
 /* */
 
     ui->lw_references->clear();
@@ -107,8 +107,10 @@ TaskFemConstraintSpring::TaskFemConstraintSpring(ViewProviderFemConstraintSpring
     }
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()),  this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()),  this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     updateUI();
 }
@@ -261,6 +263,12 @@ void TaskFemConstraintSpring::changeEvent(QEvent *)
 {
 }
 
+void TaskFemConstraintSpring::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 // TaskDialog
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintSpring.h b/src/Mod/Fem/Gui/TaskFemConstraintSpring.h
index 08d515478a..b4554fb0bf 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintSpring.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintSpring.h
@@ -31,6 +31,7 @@
 #include <Base/Quantity.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintSpring.h"
 
 #include <QObject>
@@ -41,7 +42,7 @@
 class Ui_TaskFemConstraintSpring;
 
 namespace FemGui {
-class TaskFemConstraintSpring : public TaskFemConstraint
+class TaskFemConstraintSpring : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -60,6 +61,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintSpring.ui b/src/Mod/Fem/Gui/TaskFemConstraintSpring.ui
index 244619cde1..cc4b2ea63e 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintSpring.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintSpring.ui
@@ -24,17 +24,23 @@
    <item>
     <layout class="QHBoxLayout" name="hLayout1">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.cpp b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.cpp
index a0089f3cf4..15a5672553 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.cpp
@@ -61,7 +61,7 @@ using namespace Gui;
 /* TRANSLATOR FemGui::TaskFemConstraintTemperature */
 
 TaskFemConstraintTemperature::TaskFemConstraintTemperature(ViewProviderFemConstraintTemperature *ConstraintView,QWidget *parent)
-  : TaskFemConstraint(ConstraintView, parent, "FEM_ConstraintTemperature")
+  : TaskFemConstraintOnBoundary(ConstraintView, parent, "FEM_ConstraintTemperature")
 {
     proxy = new QWidget(this);
     ui = new Ui_TaskFemConstraintTemperature();
@@ -120,8 +120,10 @@ TaskFemConstraintTemperature::TaskFemConstraintTemperature(ViewProviderFemConstr
     }
 
     //Selection buttons
-    connect(ui->btnAdd, SIGNAL(clicked()),  this, SLOT(addToSelection()));
-    connect(ui->btnRemove, SIGNAL(clicked()),  this, SLOT(removeFromSelection()));
+    connect(ui->btnAdd, SIGNAL(toggled(bool)),
+            this, SLOT(_addToSelection(bool)));
+    connect(ui->btnRemove, SIGNAL(toggled(bool)),
+            this, SLOT(_removeFromSelection(bool)));
 
     updateUI();
 }
@@ -316,6 +318,12 @@ void TaskFemConstraintTemperature::changeEvent(QEvent *)
 //    }
 }
 
+void TaskFemConstraintTemperature::clearButtons(const SelectionChangeModes notThis)
+{
+    if (notThis != refAdd) ui->btnAdd->setChecked(false);
+    if (notThis != refRemove) ui->btnRemove->setChecked(false);
+}
+
 //**************************************************************************
 // TaskDialog
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.h b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.h
index 17b1d3b4fc..c8a1e05ca7 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.h
@@ -33,6 +33,7 @@
 #include <Base/Quantity.h>
 
 #include "TaskFemConstraint.h"
+#include "TaskFemConstraintOnBoundary.h"
 #include "ViewProviderFemConstraintTemperature.h"
 
 #include <QObject>
@@ -43,7 +44,7 @@
 class Ui_TaskFemConstraintTemperature;
 
 namespace FemGui {
-class TaskFemConstraintTemperature : public TaskFemConstraint
+class TaskFemConstraintTemperature : public TaskFemConstraintOnBoundary
 {
     Q_OBJECT
 
@@ -66,6 +67,7 @@ private Q_SLOTS:
 protected:
     bool event(QEvent *e);
     void changeEvent(QEvent *e);
+    void clearButtons(const SelectionChangeModes notThis) override;
 
 private:
     void updateUI();
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.ui b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.ui
index 5180f72406..d36271a5d4 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintTemperature.ui
+++ b/src/Mod/Fem/Gui/TaskFemConstraintTemperature.ui
@@ -24,17 +24,23 @@
    <item>
     <layout class="QHBoxLayout" name="hLayout1">
      <item>
-      <widget class="QPushButton" name="btnAdd">
+      <widget class="QToolButton" name="btnAdd">
        <property name="text">
         <string>Add</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item>
-      <widget class="QPushButton" name="btnRemove">
+      <widget class="QToolButton" name="btnRemove">
        <property name="text">
         <string>Remove</string>
        </property>
+       <property name="checkable">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
     </layout>