diff --git a/tests/corner_3d_connectors.scad b/tests/corner_3d_connectors.scad
index 3a34bc6..668ee0d 100644
--- a/tests/corner_3d_connectors.scad
+++ b/tests/corner_3d_connectors.scad
@@ -21,7 +21,7 @@ include <../vitamins/extrusions.scad>
 
 module corner_connector(with_profiles = false, corner_connector_type, extrusion_type) {
     extrusion_length = 40;
-    corner_3d_connector(corner_connector_type);
+    corner_3d_connector(corner_connector_type, grub_screws=true);
     if(with_profiles){
         translate([0,0,extrusion_length/2])
         extrusion(extrusion_type, extrusion_length);
@@ -48,6 +48,8 @@ translate([220,0,0])
 corner_connector(with_profiles, corner_3d_connector_4040, E4040);
 }
 
+$show_threads=true;
 corner_connectors();
 translate ([0,100,0])
-corner_connectors(true);
\ No newline at end of file
+corner_connectors(true);
+
diff --git a/vitamins/corner_3d_connector.scad b/vitamins/corner_3d_connector.scad
index f65931c..f320997 100644
--- a/vitamins/corner_3d_connector.scad
+++ b/vitamins/corner_3d_connector.scad
@@ -56,7 +56,8 @@ function corner_3d_connector_get_x_offset(type) = [corner_3d_connector_outer_sid
 function corner_3d_connector_get_x_rot(type) = [0,90,0]; //! helper function to rotate the y beam
 
 
-module corner_3d_connector (type, thread = false, grub_screws = true) { //! draw the specified corner_3d_connector
+module corner_3d_connector (type, grub_screws = true) { //! draw the specified corner_3d_connector
+
     nut_screw_dia = corner_3d_connector_nut_screw_dia(type);
     nut_dia = corner_3d_connector_nut_dia(type);
     nut_thickness = corner_3d_connector_nut_thickness(type);
@@ -125,7 +126,7 @@ module corner_3d_connector (type, thread = false, grub_screws = true) { //! draw
                         rotate([0,90,0])
                         difference() {
                             cylinder(h = nut_nyloc_thickness+0.02, d=nut_screw_dia, center = false);
-                            if(thread) {
+                            if(show_threads ) {
                                 female_metric_thread(nut_screw_dia, metric_coarse_pitch(nut_screw_dia), nut_nyloc_thickness, center = false);
                             }
 
@@ -149,7 +150,7 @@ module corner_3d_connector (type, thread = false, grub_screws = true) { //! draw
                             rotate([0,90,0])
                             difference() {
                                 cylinder(h = nut_nyloc_thickness+0.02, d=nut_screw_dia, center = false);
-                                if(thread) {
+                                if(show_threads ) {
                                     female_metric_thread(nut_screw_dia, metric_coarse_pitch(nut_screw_dia), nut_nyloc_thickness, center = false);
                                 }
                             }