diff --git a/core/src/net/sf/openrocket/file/openrocket/importt/AnglePositionSetter.java b/core/src/net/sf/openrocket/file/openrocket/importt/AnglePositionSetter.java
index 06b6d97d2..4843f6872 100644
--- a/core/src/net/sf/openrocket/file/openrocket/importt/AnglePositionSetter.java
+++ b/core/src/net/sf/openrocket/file/openrocket/importt/AnglePositionSetter.java
@@ -20,9 +20,9 @@ class AnglePositionSetter implements Setter {
 		
 		double pos;
 		try {
-			pos = Double.parseDouble(value) * Math.PI / 180.0 ;
+			pos = Math.toRadians(Double.parseDouble(value));
 		} catch (NumberFormatException e) {
-			warnings.add(String.format("Warning: invalid value radius position. value=%s    class: %s", value, c.getClass().getCanonicalName() ));
+			warnings.add(String.format("Warning: invalid angle position. value=%s  (degrees)  class: %s", value, c.getClass().getCanonicalName() ));
 			return;
 		}
 
diff --git a/core/src/net/sf/openrocket/file/openrocket/savers/FinSetSaver.java b/core/src/net/sf/openrocket/file/openrocket/savers/FinSetSaver.java
index c7d5ded18..ef6c25212 100644
--- a/core/src/net/sf/openrocket/file/openrocket/savers/FinSetSaver.java
+++ b/core/src/net/sf/openrocket/file/openrocket/savers/FinSetSaver.java
@@ -20,7 +20,7 @@ public class FinSetSaver extends ExternalComponentSaver {
 		elements.add("<thickness>" + fins.getThickness() + "</thickness>");
 		elements.add("<crosssection>" + fins.getCrossSection().name().toLowerCase(Locale.ENGLISH)
 				+ "</crosssection>");
-		elements.add("<cant>" + (fins.getCantAngle() * 180.0 / Math.PI) + "</cant>");
+		elements.add("<cant>" + Math.toDegrees(fins.getCantAngle()) + "</cant>");
 		
 		// Save fin tabs only if they exist (compatibility with file version < 1.1)
 		if (!MathUtil.equals(fins.getTabHeight(), 0) &&
diff --git a/core/src/net/sf/openrocket/rocketcomponent/FinSet.java b/core/src/net/sf/openrocket/rocketcomponent/FinSet.java
index 54b8b683b..749855850 100644
--- a/core/src/net/sf/openrocket/rocketcomponent/FinSet.java
+++ b/core/src/net/sf/openrocket/rocketcomponent/FinSet.java
@@ -35,7 +35,7 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	/**
 	 * Maximum allowed cant of fins.
 	 */
-	public static final double MAX_CANT = (15.0 * Math.PI / 180);
+	public static final double MAX_CANT_RADIANS = (15.0 * Math.PI / 180);
 	
 	public enum CrossSection {
 		//// Square
@@ -78,13 +78,13 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	 * Rotation angle of the first fin.  Zero corresponds to the positive y-axis.
 	 */
 	private AngleMethod angleMethod = AngleMethod.RELATIVE;
-	private double firstFinOffset = 0;
+	private double firstFinOffsetRadians = 0;
 	private Transformation baseRotation = Transformation.IDENTITY;  // initially, rotate by 0 degrees.
 
 	/**
 	 * Cant angle of fins.
 	 */
-	private double cantAngle = 0;
+	private double cantRadians = 0;
 	
 	/* Cached value: */
 	private Transformation cantRotation = null;
@@ -194,26 +194,33 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 		setAngleOffset(r);
 	}
 	
+	/**
+	 * @return angle current cant angle, in radians 
+	 */
 	public double getCantAngle() {
-		return cantAngle;
+		return cantRadians;
 	}
 	
-	public void setCantAngle(double cant) {
-		cant = MathUtil.clamp(cant, -MAX_CANT, MAX_CANT);
-		if (MathUtil.equals(cant, cantAngle))
+	/**
+	 * 
+	 * @param cant -- new cant angle, in radians
+	 */
+	public void setCantAngle(final double newCantRadians) {
+		final double clampedCant = MathUtil.clamp(newCantRadians, -MAX_CANT_RADIANS, MAX_CANT_RADIANS);
+		if (MathUtil.equals(clampedCant, this.cantRadians))
 			return;
-		this.cantAngle = cant;
+		this.cantRadians = clampedCant;
 		fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 	}
 	
 	
 	public Transformation getCantRotation() {
 		if (cantRotation == null) {
-			if (MathUtil.equals(cantAngle, 0)) {
+			if (MathUtil.equals(this.cantRadians, 0)) {
 				cantRotation = Transformation.IDENTITY;
 			} else {
 				Transformation t = new Transformation(-length / 2, 0, 0);
-				t = Transformation.rotate_y(cantAngle).applyTransformation(t);
+				t = Transformation.rotate_y(cantRadians).applyTransformation(t);
 				t = new Transformation(length / 2, 0, 0).applyTransformation(t);
 				cantRotation = t;
 			}
@@ -928,16 +935,15 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	
 	@Override
 	public double getAngleOffset() {
-		return firstFinOffset;
+		return firstFinOffsetRadians;
 	}
 
-
 	@Override
-	public void setAngleOffset(double angle) {
-		angle = MathUtil.reduce180(angle);
-		if (MathUtil.equals(angle, firstFinOffset))
+	public void setAngleOffset(final double angleRadians) {
+		final double reducedAngle = MathUtil.reducePI(angleRadians);
+		if (MathUtil.equals(reducedAngle, firstFinOffsetRadians))
 			return;
-		firstFinOffset = angle;
+		firstFinOffsetRadians = reducedAngle;
 		fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 	}
 
@@ -947,13 +953,12 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	}
 	
 	@Override
-	public double[] getInstanceAngles(){		
-		final double baseAngle = getAngleOffset();
-		final double incrAngle = getInstanceAngleIncrement();
+	public double[] getInstanceAngles() {
+		final double angleIncrementRadians = getInstanceAngleIncrement();
 		
 		double[] result = new double[ getFinCount()]; 
-		for( int i=0; i<getFinCount(); ++i){
-			result[i] = MathUtil.reduce360( baseAngle + incrAngle*i);
+		for( int finNumber=0; finNumber < getFinCount(); ++finNumber ){
+			result[finNumber] = MathUtil.reduce2PI( firstFinOffsetRadians + angleIncrementRadians*finNumber);
 		}
 		
 		return result;
@@ -1020,8 +1025,8 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 		FinSet src = (FinSet) c;
 		this.finCount = src.finCount;
 		this.finRotation = src.finRotation;
-		this.firstFinOffset = src.firstFinOffset;
-		this.cantAngle = src.cantAngle;
+		this.firstFinOffsetRadians = src.firstFinOffsetRadians;
+		this.cantRadians = src.cantRadians;
 		this.cantRotation = src.cantRotation;
 		this.thickness = src.thickness;
 		this.crossSection = src.crossSection;
@@ -1066,7 +1071,6 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	}
 
 	/**
-<<<<<<< HEAD
 	 * use this for calculating physical properties, and routine drawing
 	 *
 	 * @return points representing the fin-root points, relative to ( x: fin-front, y: centerline ) i.e. relto: fin Component reference point
diff --git a/core/src/net/sf/openrocket/rocketcomponent/position/AnglePositionable.java b/core/src/net/sf/openrocket/rocketcomponent/position/AnglePositionable.java
index 577b3bdf2..33831856b 100644
--- a/core/src/net/sf/openrocket/rocketcomponent/position/AnglePositionable.java
+++ b/core/src/net/sf/openrocket/rocketcomponent/position/AnglePositionable.java
@@ -2,8 +2,14 @@ package net.sf.openrocket.rocketcomponent.position;
 
 public interface AnglePositionable {
 
+	/**
+	 * @return angle to the first element, in radians
+	 */
 	public double getAngleOffset();
 	
+	/**
+	 * @param new offset angle, in radians
+	 */
 	public void setAngleOffset(final double angle);
 	
 	public AngleMethod getAngleMethod( );
diff --git a/core/src/net/sf/openrocket/util/MathUtil.java b/core/src/net/sf/openrocket/util/MathUtil.java
index e1e986b24..ef6cc4956 100644
--- a/core/src/net/sf/openrocket/util/MathUtil.java
+++ b/core/src/net/sf/openrocket/util/MathUtil.java
@@ -211,10 +211,13 @@ public class MathUtil {
 
 	/**
 	 * Reduce the angle x to the range 0 - 2*PI.
-	 * @param x  Original angle.
+	 * 
+	 * @deprecated function refers to units:degrees, but operates in units:radians. Please use 'MathUtil.reduce2PI'
+     * @param x  Original angle.
 	 * @return   The equivalent angle in the range 0 ... 2*PI.
 	 */
-	public static double reduce360(double x) {
+    @Deprecated
+    public static double reduce360(double x) {
 		double d = Math.floor(x / (2 * Math.PI));
 		return x - d * 2 * Math.PI;
 	}
@@ -224,9 +227,11 @@ public class MathUtil {
 	 * 
 	 * Either -PI and PI might be returned, depending on the rounding function. 
 	 * 
-	 * @param x  Original angle.
+	 * @deprecated function refers to units:degrees, but operates in units:radians. Please use 'MathUtil.reducePI'
+     * @param x  Original angle.
 	 * @return   The equivalent angle in the range -PI ... PI.
 	 */
+	@Deprecated
 	public static double reduce180(double x) {
 		double d = Math.rint(x / (2 * Math.PI));
 		return x - d * 2 * Math.PI;
diff --git a/core/test/net/sf/openrocket/rocketcomponent/FinSetTest.java b/core/test/net/sf/openrocket/rocketcomponent/FinSetTest.java
index 3dd94dd5b..15a39a401 100644
--- a/core/test/net/sf/openrocket/rocketcomponent/FinSetTest.java
+++ b/core/test/net/sf/openrocket/rocketcomponent/FinSetTest.java
@@ -50,8 +50,24 @@ public class FinSetTest extends BaseTestCase {
 
         fins.setFilletRadius(0.0);
 
-        return fins;
-	}
+        fins.setAngleMethod(AngleMethod.FIXED);
+        fins.setAngleOffset(Math.toRadians(90.0));
+
+        fins.setCantAngle(Math.toRadians(3.0));
+
+	    return fins;
+    }
+
+    @Test
+    public void testAngleOffset() {
+        final FinSet fins = FinSetTest.createSimpleFin();
+
+        assertEquals("Angle Offset Doesn't match!", Math.PI/2, fins.getAngleOffset(), EPSILON);
+        assertEquals("Angle Offset Doesn't match!", 90.0, Math.toDegrees(fins.getAngleOffset()), EPSILON);
+        
+        assertEquals("Cant angle doesn't match!", Math.PI/60, fins.getCantAngle(), EPSILON);
+        assertEquals("Cant angle doesn't match!", 3.0, Math.toDegrees(fins.getCantAngle()), EPSILON);
+   }
 
 	@Test
 	public void testTabLocation() {
diff --git a/swing/src/net/sf/openrocket/gui/configdialog/EllipticalFinSetConfig.java b/swing/src/net/sf/openrocket/gui/configdialog/EllipticalFinSetConfig.java
index e37ffa058..9e7fa4c68 100644
--- a/swing/src/net/sf/openrocket/gui/configdialog/EllipticalFinSetConfig.java
+++ b/swing/src/net/sf/openrocket/gui/configdialog/EllipticalFinSetConfig.java
@@ -69,14 +69,14 @@ public class EllipticalFinSetConfig extends FinSetConfig {
 		panel.add(label);
 		
 		m = new DoubleModel(component, "CantAngle", UnitGroup.UNITS_ANGLE,
-				-FinSet.MAX_CANT, FinSet.MAX_CANT);
+				-FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS);
 		
 		spin = new JSpinner(m.getSpinnerModel());
 		spin.setEditor(new SpinnerEditor(spin));
 		panel.add(spin, "growx");
 		
 		panel.add(new UnitSelector(m), "growx");
-		panel.add(new BasicSlider(m.getSliderModel(-FinSet.MAX_CANT, FinSet.MAX_CANT)),
+		panel.add(new BasicSlider(m.getSliderModel(-FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS)),
 				"w 100lp, wrap");
 		
 		
diff --git a/swing/src/net/sf/openrocket/gui/configdialog/FreeformFinSetConfig.java b/swing/src/net/sf/openrocket/gui/configdialog/FreeformFinSetConfig.java
index 37ccc6118..69f84d0a0 100644
--- a/swing/src/net/sf/openrocket/gui/configdialog/FreeformFinSetConfig.java
+++ b/swing/src/net/sf/openrocket/gui/configdialog/FreeformFinSetConfig.java
@@ -134,14 +134,14 @@ public class FreeformFinSetConfig extends FinSetConfig {
 		label.setToolTipText(trans.get("FreeformFinSetCfg.lbl.ttip.Fincant"));
 		panel.add(label);
 		
-		m = new DoubleModel(component, "CantAngle", UnitGroup.UNITS_ANGLE, -FinSet.MAX_CANT, FinSet.MAX_CANT);
+		m = new DoubleModel(component, "CantAngle", UnitGroup.UNITS_ANGLE, -FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS);
 		
 		spin = new JSpinner(m.getSpinnerModel());
 		spin.setEditor(new SpinnerEditor(spin));
 		panel.add(spin, "growx");
 		
 		panel.add(new UnitSelector(m), "growx");
-		panel.add(new BasicSlider(m.getSliderModel(-FinSet.MAX_CANT, FinSet.MAX_CANT)), "w 100lp, wrap 40lp");
+		panel.add(new BasicSlider(m.getSliderModel(-FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS)), "w 100lp, wrap 40lp");
 		
 		
 		
diff --git a/swing/src/net/sf/openrocket/gui/configdialog/TrapezoidFinSetConfig.java b/swing/src/net/sf/openrocket/gui/configdialog/TrapezoidFinSetConfig.java
index 1035009c1..804d698e9 100644
--- a/swing/src/net/sf/openrocket/gui/configdialog/TrapezoidFinSetConfig.java
+++ b/swing/src/net/sf/openrocket/gui/configdialog/TrapezoidFinSetConfig.java
@@ -75,14 +75,14 @@ public class TrapezoidFinSetConfig extends FinSetConfig {
 			label.setToolTipText(trans.get("TrapezoidFinSetCfg.lbl.ttip.Fincant"));
 			panel.add(label);
 
-			final DoubleModel cantModel = new DoubleModel(component, "CantAngle", UnitGroup.UNITS_ANGLE, -FinSet.MAX_CANT, FinSet.MAX_CANT);
+			final DoubleModel cantModel = new DoubleModel(component, "CantAngle", UnitGroup.UNITS_ANGLE, -FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS);
 
 			final JSpinner cantSpinner = new JSpinner(cantModel.getSpinnerModel());
 			cantSpinner.setEditor(new SpinnerEditor(cantSpinner));
 			panel.add(cantSpinner, "growx");
 
 			panel.add(new UnitSelector(cantModel), "growx");
-			panel.add(new BasicSlider(cantModel.getSliderModel(-FinSet.MAX_CANT, FinSet.MAX_CANT)),
+			panel.add(new BasicSlider(cantModel.getSliderModel(-FinSet.MAX_CANT_RADIANS, FinSet.MAX_CANT_RADIANS)),
 					"w 100lp, wrap");
 		}