diff --git a/tests/sk_brackets.scad b/tests/sk_brackets.scad
index 9c8d02e..aa19505 100644
--- a/tests/sk_brackets.scad
+++ b/tests/sk_brackets.scad
@@ -20,12 +20,19 @@ include <../core.scad>
 use <../utils/layout.scad>
 
 include <../vitamins/sk_brackets.scad>
+include <../vitamins/extrusions.scad>
 
 module sk_brackets() {
-    screws = [M5_cap_screw, M5_cap_screw, M4_cap_screw, M5_cap_screw];
-    nuts = [undef, M5_nut, M4_sliding_t_nut, M5_sliding_t_nut];
-    layout([for(s = sk_brackets) 1.5 * sk_size(s)[1]])
-        sk_bracket_assembly(sk_brackets[$i], screw_type = screws[$i], nut_type = nuts[$i]);
+    screws = [M4_dome_screw, M4_cap_screw, M5_cap_screw, M5_cap_screw];
+    nuts = [M4_hammer_nut, M4_sliding_t_nut, M5_sliding_t_nut, undef];
+    // channel depth = 6 for 2020 extrusion, 9 for 3030 extrusion
+    depths = [6, 6, 9, 0];
+    layout([for(s = sk_brackets) 1.5 * sk_size(s)[1]]) {
+        sk_bracket_assembly(sk_brackets[$i], screw_type = screws[$i], nut_type = nuts[$i], max_screw_depth = depths[$i]);
+        translate([0, -sk_hole_offset(sk_brackets[$i]) - extrusion_width($i < 2 ? E2020 : E3030) / 2, 0])
+            rotate([0, 90, 0])
+                extrusion($i < 2 ? E2020 : E3030, 20);
+    }
 }
 
 if($preview)
diff --git a/vitamins/sk_bracket.scad b/vitamins/sk_bracket.scad
index 43d7c80..803e80e 100644
--- a/vitamins/sk_bracket.scad
+++ b/vitamins/sk_bracket.scad
@@ -100,7 +100,7 @@ module sk_bracket_hole_positions(type) { //! Place children at hole positions
                 children();
 }
 
-module sk_bracket_assembly(type, part_thickness = 2, screw_type = M5_cap_screw, nut_type = undef) { //! Assembly with fasteners in place
+module sk_bracket_assembly(type, part_thickness = 2, screw_type = M5_cap_screw, nut_type = undef, max_screw_depth = 6) { //! Assembly with fasteners in place
     sk_bracket(type);
 
     screw_type = is_undef(screw_type) ? scs_screw(type) : screw_type;
@@ -110,9 +110,8 @@ module sk_bracket_assembly(type, part_thickness = 2, screw_type = M5_cap_screw,
     nut_washer_thickness = nut_washer_type ? washer_thickness(nut_washer_type) : 0;
 
     nut_offset = sk_base_height(type) + part_thickness;
-    screw_length = nut_washer_type ? screw_longer_than(nut_offset + screw_washer_thickness + nut_washer_thickness + nut_thickness(nut_type))
-                                   : screw_shorter_than(nut_offset + screw_washer_thickness + nut_thickness(nut_type) + 2);
-
+    screw_length = max_screw_depth ? screw_shorter_than(sk_base_height(type) + screw_washer_thickness + max_screw_depth)
+                                   : screw_longer_than(nut_offset + screw_washer_thickness + nut_washer_thickness + nut_thickness(nut_type));
     sk_bracket_hole_positions(type) {
         screw_and_washer(screw_type, screw_length);
         translate_z(-nut_offset)
@@ -123,3 +122,4 @@ module sk_bracket_assembly(type, part_thickness = 2, screw_type = M5_cap_screw,
                     sliding_t_nut(nut_type);
     }
 }
+