diff --git a/modules/ui/components/controls/ComboBoxControl.jsx b/modules/ui/components/controls/ComboBoxControl.jsx
new file mode 100644
index 00000000..57541c9f
--- /dev/null
+++ b/modules/ui/components/controls/ComboBoxControl.jsx
@@ -0,0 +1,15 @@
+import React from 'react';
+
+export default class ComboBoxControl extends React.Component {
+  
+  render() {
+    let {onChange, value, children} = this.props;
+    return <select value={value} onChange={e => onChange(e.target.value)}>
+      {children}
+    </select>  
+  }
+}
+
+export function ComboBoxOption({children, value}) {
+  return <option value={value}>{children}</option>
+}
diff --git a/web/app/cad/craft/primitives/booleanOptionHelper.js b/web/app/cad/craft/primitives/booleanOptionHelper.js
new file mode 100644
index 00000000..1f6c2c38
--- /dev/null
+++ b/web/app/cad/craft/primitives/booleanOptionHelper.js
@@ -0,0 +1,10 @@
+
+export function assignBooleanParams(execParams, rawParams, getAllShells) {
+  if (rawParams.boolean) {
+    execParams.boolean = {
+      type: rawParams.boolean,
+      operands: getAllShells()
+    }
+  }
+  return execParams;  
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/box/BoxWizard.jsx b/web/app/cad/craft/primitives/box/BoxWizard.jsx
index b1827c96..fc4c2fe9 100644
--- a/web/app/cad/craft/primitives/box/BoxWizard.jsx
+++ b/web/app/cad/craft/primitives/box/BoxWizard.jsx
@@ -1,6 +1,7 @@
 import React from 'react';
 import {Group} from '../../wizard/components/form/Form';
 import {NumberField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import BooleanChoice from '../../wizard/components/form/BooleanChioce';
 
 export default function BoxWizard() {
   return <Group>
@@ -8,5 +9,6 @@ export default function BoxWizard() {
     <NumberField name='width' />
     <NumberField name='height' />
     <NumberField name='depth' />
+    <BooleanChoice name='boolean' />
   </Group>;
 }
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/box/boxOperation.js b/web/app/cad/craft/primitives/box/boxOperation.js
index c56cfab1..20465777 100644
--- a/web/app/cad/craft/primitives/box/boxOperation.js
+++ b/web/app/cad/craft/primitives/box/boxOperation.js
@@ -2,16 +2,18 @@ import BoxWizard from './BoxWizard';
 import {BoxGeometry} from 'three';
 import schema from './boxOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
-import CSys from '../../../../math/csys';
 import datumConsumingOperation from '../datumConsumingOperation';
+import {assignBooleanParams} from '../booleanOptionHelper';
 
 function run(params, services) {
-  return datumConsumingOperation(params, services, csys => services.craftEngine.createBox({
-    csys,
-    width: params.width,
-    height: params.height,
-    depth: params.depth
-  }));
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createBox(
+    assignBooleanParams({
+      csys,
+      width: params.width,
+      height: params.height,
+      depth: params.depth
+    }, params, services.cadRegistry.getAllShells)
+  ));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/cone/ConeWizard.jsx b/web/app/cad/craft/primitives/cone/ConeWizard.jsx
index 45230ae0..1ecf47c3 100644
--- a/web/app/cad/craft/primitives/cone/ConeWizard.jsx
+++ b/web/app/cad/craft/primitives/cone/ConeWizard.jsx
@@ -1,6 +1,7 @@
 import React from 'react';
 import {Group} from '../../wizard/components/form/Form';
 import {NumberField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import BooleanChoice from '../../wizard/components/form/BooleanChioce';
 
 export default function TorusWizard() {
   return <Group>
@@ -8,5 +9,6 @@ export default function TorusWizard() {
     <NumberField name='radius' />
     <NumberField name='frustum' />
     <NumberField name='height' />
+    <BooleanChoice name='boolean' />
   </Group>;
 }
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/cone/coneOperation.js b/web/app/cad/craft/primitives/cone/coneOperation.js
index 05616160..8c5931c4 100644
--- a/web/app/cad/craft/primitives/cone/coneOperation.js
+++ b/web/app/cad/craft/primitives/cone/coneOperation.js
@@ -5,14 +5,17 @@ import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
 import CSys from '../../../../math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
 import datumConsumingOperation from '../datumConsumingOperation';
+import {assignBooleanParams} from '../booleanOptionHelper';
 
 function run(params, services) {
-  return datumConsumingOperation(params, services, csys => services.craftEngine.createCone({
-    csys,
-    radius: params.radius,
-    frustum: params.frustum,
-    height: params.height
-  }));
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createCone(
+    assignBooleanParams({
+      csys,
+      radius: params.radius,
+      frustum: params.frustum,
+      height: params.height
+    }, params, services.cadRegistry.getAllShells)
+  ));
 }
 
 function previewer(ctx, initialParams) {
diff --git a/web/app/cad/craft/primitives/cylinder/CylinderWizard.jsx b/web/app/cad/craft/primitives/cylinder/CylinderWizard.jsx
index dd3bbcaf..d04f1927 100644
--- a/web/app/cad/craft/primitives/cylinder/CylinderWizard.jsx
+++ b/web/app/cad/craft/primitives/cylinder/CylinderWizard.jsx
@@ -1,11 +1,13 @@
 import React from 'react';
 import {Group} from '../../wizard/components/form/Form';
 import {NumberField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import BooleanChoice from '../../wizard/components/form/BooleanChioce';
 
 export default function CylinderWizard() {
   return <Group>
     <ReadOnlyValueField name='datum' placeholder='origin'/>
     <NumberField name='radius' />
     <NumberField name='height' />
+    <BooleanChoice name='boolean' />
   </Group>;
 }
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/cylinder/cylinderOperation.js b/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
index a1be3947..f090710a 100644
--- a/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
+++ b/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
@@ -3,13 +3,16 @@ import schema from './cylinderOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
 import CylinderWizard from './CylinderWizard';
 import datumConsumingOperation from '../datumConsumingOperation';
+import {assignBooleanParams} from '../booleanOptionHelper';
 
 function run(params, services) {
-  return datumConsumingOperation(params, services, csys => services.craftEngine.createCylinder({
-    csys,
-    radius: params.radius,
-    height: params.height
-  }));
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createCylinder(
+    assignBooleanParams({
+      csys,
+      radius: params.radius,
+      height: params.height
+    }, params, services.cadRegistry.getAllShells)
+  ));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/sphere/SphereWizard.jsx b/web/app/cad/craft/primitives/sphere/SphereWizard.jsx
index ac0105fd..eae54fbf 100644
--- a/web/app/cad/craft/primitives/sphere/SphereWizard.jsx
+++ b/web/app/cad/craft/primitives/sphere/SphereWizard.jsx
@@ -1,10 +1,12 @@
 import React from 'react';
 import {Group} from '../../wizard/components/form/Form';
 import {NumberField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import BooleanChoice from '../../wizard/components/form/BooleanChioce';
 
 export default function SphereWizard() {
   return <Group>
     <ReadOnlyValueField name='datum' placeholder='origin'/>
     <NumberField name='radius' />
+    <BooleanChoice name='boolean' />
   </Group>;
 }
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/sphere/sphereOperation.js b/web/app/cad/craft/primitives/sphere/sphereOperation.js
index 0e9394bc..0802fde6 100644
--- a/web/app/cad/craft/primitives/sphere/sphereOperation.js
+++ b/web/app/cad/craft/primitives/sphere/sphereOperation.js
@@ -3,12 +3,15 @@ import schema from './sphereOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
 import SphereWizard from './SphereWizard';
 import datumConsumingOperation from '../datumConsumingOperation';
+import {assignBooleanParams} from '../booleanOptionHelper';
 
 function run(params, services) {
-  return datumConsumingOperation(params, services, csys => services.craftEngine.createSphere({
-    csys,
-    radius: params.radius,
-  }));
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createSphere(
+    assignBooleanParams({
+      csys,
+      radius: params.radius,
+    }, params, services.cadRegistry.getAllShells)
+  ));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/torus/TorusWizard.jsx b/web/app/cad/craft/primitives/torus/TorusWizard.jsx
index a63e6a5a..e8f41c6e 100644
--- a/web/app/cad/craft/primitives/torus/TorusWizard.jsx
+++ b/web/app/cad/craft/primitives/torus/TorusWizard.jsx
@@ -1,11 +1,13 @@
 import React from 'react';
 import {Group} from '../../wizard/components/form/Form';
 import {NumberField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import BooleanChoice from '../../wizard/components/form/BooleanChioce';
 
 export default function TorusWizard() {
   return <Group>
     <ReadOnlyValueField name='datum' placeholder='origin'/>
     <NumberField name='radius' />
     <NumberField name='tube' />
+    <BooleanChoice name='boolean' />
   </Group>;
 }
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/torus/torusOperation.js b/web/app/cad/craft/primitives/torus/torusOperation.js
index 0d354233..7b7232e4 100644
--- a/web/app/cad/craft/primitives/torus/torusOperation.js
+++ b/web/app/cad/craft/primitives/torus/torusOperation.js
@@ -5,13 +5,16 @@ import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
 import CSys from '../../../../math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
 import datumConsumingOperation from '../datumConsumingOperation';
+import {assignBooleanParams} from '../booleanOptionHelper';
 
 function run(params, services) {
-  return datumConsumingOperation(params, services, csys => services.craftEngine.createTorus({
-    csys,
-    radius: params.radius,
-    tube: params.tube
-  }));
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createTorus(    
+    assignBooleanParams({
+      csys,
+      radius: params.radius,
+      tube: params.tube
+    }, params, services.cadRegistry.getAllShells)
+  ));
 }
 
 function previewer(ctx, initialParams) {
diff --git a/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx b/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx
new file mode 100644
index 00000000..10ed7bda
--- /dev/null
+++ b/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx
@@ -0,0 +1,12 @@
+import React from 'react';
+import {ComboBoxOption} from 'ui/components/controls/ComboBoxControl';
+import {ComboBoxField} from './Fields';
+
+export default function BooleanChoice(props) {
+  return <ComboBoxField {...props}>
+    <ComboBoxOption value={null}>{'<none>'}</ComboBoxOption>
+    <ComboBoxOption value={'INTERSECT'}>intersect</ComboBoxOption>
+    <ComboBoxOption value={'SUBTRACT'}>subtract</ComboBoxOption>
+    <ComboBoxOption value={'UNION'}>union</ComboBoxOption>
+  </ComboBoxField>
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/wizard/components/form/Fields.jsx b/web/app/cad/craft/wizard/components/form/Fields.jsx
index 8f31ec55..ca209b16 100644
--- a/web/app/cad/craft/wizard/components/form/Fields.jsx
+++ b/web/app/cad/craft/wizard/components/form/Fields.jsx
@@ -5,9 +5,11 @@ import TextControl from 'ui/components/controls/TextControl';
 import RadioButtons from 'ui/components/controls/RadioButtons';
 import CheckboxControl from 'ui/components/controls/CheckboxControl';
 import ReadOnlyValueControl from 'ui/components/controls/ReadOnlyValueControl';
+import ComboBoxControl from 'ui/components/controls/ComboBoxControl';
 
 export const NumberField = attachToForm(formField(NumberControl));
 export const TextField = attachToForm(formField(TextControl));
 export const RadioButtonsField = attachToForm(formField(RadioButtons));
 export const CheckboxField = attachToForm(formField(CheckboxControl));
+export const ComboBoxField = attachToForm(formField(ComboBoxControl));
 export const ReadOnlyValueField = attachToForm(formField(ReadOnlyValueControl));