diff --git a/insert/insert.scad b/insert/insert.scad
new file mode 100644
index 0000000..9f5d874
--- /dev/null
+++ b/insert/insert.scad
@@ -0,0 +1,9 @@
+$fn=100;
+h_cylinder=19;
+d_cylinder=8;
+d_screw=5;
+difference()
+{
+  cylinder(h=h_cylinder, r=d_cylinder/2, center=true);
+  cylinder(h=h_cylinder+0.001, r=(d_screw*0.8)/2, center=true);
+}