diff --git a/nhf/touhou/houjuu_nue/joints.py b/nhf/touhou/houjuu_nue/joints.py
index 87bc098..ca6003e 100644
--- a/nhf/touhou/houjuu_nue/joints.py
+++ b/nhf/touhou/houjuu_nue/joints.py
@@ -956,7 +956,7 @@ class DiskJoint(Model):
 
     @property
     def radius_axle(self) -> float:
-        return self.axle_bolt.diam_thread
+        return self.axle_bolt.diam_thread / 2
 
     @property
     def total_thickness(self) -> float: