diff --git a/ExcellonScaler.cs b/ExcellonScaler.cs
index bac7046..d8f3316 100644
--- a/ExcellonScaler.cs
+++ b/ExcellonScaler.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Text.RegularExpressions;
 
 namespace DrillTools.Integration
@@ -103,7 +104,7 @@ namespace DrillTools.Integration
             long xNew = (long)Math.Round(xOrig * kx);
             long yNew = (long)Math.Round(yOrig * ky);
 
-            return $"X{xNew}Y{yNew}";
+            return $"X{FormatCoordinateValue(xNew)}Y{FormatCoordinateValue(yNew)}";
         }
 
         /// <summary>
@@ -148,7 +149,20 @@ namespace DrillTools.Integration
             long newEndX = cxNew + dx;
             long newEndY = cyNew + dy;
 
-            return $"X{newStartX}Y{newStartY}G85X{newEndX}Y{newEndY}";
+            return
+                $"X{FormatCoordinateValue(newStartX)}Y{FormatCoordinateValue(newStartY)}" +
+                $"G85X{FormatCoordinateValue(newEndX)}Y{FormatCoordinateValue(newEndY)}";
+        }
+
+        /// <summary>
+        /// 将坐标数值格式化为钻带使用的 6 位坐标文本，负数保留负号。
+        /// </summary>
+        private static string FormatCoordinateValue(long value)
+        {
+            if (value < 0)
+                return "-" + Math.Abs(value).ToString("D6", CultureInfo.InvariantCulture);
+
+            return value.ToString("D6", CultureInfo.InvariantCulture);
         }
     }
 }