diff --git a/lib/panel_clamp.scad b/lib/panel_clamp.scad
index 9519b30..50f6957 100644
--- a/lib/panel_clamp.scad
+++ b/lib/panel_clamp.scad
@@ -37,9 +37,43 @@ module panel_clamp(face, screw, style, dia_x, dia_y, height, mask) {
     roty = 0;
     rotz = face == "left" ? 90 : face == "right" ? 270 : 0;
 
-    if(enablemask == true && mstyle == "default") {
+    if(enablemask == true) {
         rotate([rotx,roty,rotz]) {
-            cylinder(d=dia_y, h=height);
+            if(mstyle == "default") {
+                cylinder(d=dia_y, h=height);
+            }
+            if(screw == "m2" && mstyle == "holes") {
+                translate([(-dia_y-(nuts[2][0]+.5)/2)/2, 0, 2.25]) rotate([0,90,0]) 
+                    cylinder(d=nuts[0][0]+.5, h=dia_y+2);
+                translate([-(dia_y/2), 0, 2.25]) rotate([0,90,0]) 
+                    cylinder(d=nuts[0][1]*2/sqrt(3), h=dia_y*.375, $fn=6);
+                translate([nuts[0][0]+.5, 0, 2.25]) rotate([0,90,0]) 
+                    cylinder(d=nuts[0][1]+.5, h=dia_y*.375);
+            }
+            if(screw == "m2.5" && mstyle == "holes") {
+                translate([(-dia_y-(nuts[2][0]+.5)/2)/2, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[1][0]+.5, h=dia_y+2);
+                translate([-(dia_y/2), 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[1][1]*2/sqrt(3), h=dia_y*.375, $fn=6);
+                translate([nuts[1][0]+.5, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[1][1]+.5, h=dia_y*.375);
+            }
+            if(screw == "m3" && mstyle == "holes") {
+                translate([(-dia_y-(nuts[2][0]+.5)/2)/2, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[2][0]+.5, h=dia_y+2);
+                translate([-(dia_y/2), 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[2][1]*2/sqrt(3), h=dia_y*.375, $fn=6);
+                translate([nuts[2][0]+.5, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[2][1]+.5, h=dia_y*.375);
+            }
+            if(screw == "m4" && mstyle == "holes") {
+                translate([(-dia_y-(nuts[2][0]+.5)/2)/2, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[3][0]+.5, h=dia_y+2);
+                translate([-(dia_y/2), 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[3][1]*2/sqrt(3), h=dia_y*.375, $fn=6);
+                translate([nuts[3][0]+.5, 0, 3]) rotate([0,90,0]) 
+                    cylinder(d=nuts[3][1]+.5, h=dia_y*.375);
+            }
         }
     }
     if(enablemask == false) {
diff --git a/mod/case_rack.scad b/mod/case_rack.scad
index b8de776..b9ca38d 100644
--- a/mod/case_rack.scad
+++ b/mod/case_rack.scad
@@ -387,6 +387,24 @@ if(case_design == "rack" && side == "bottom") {
                             vent(2,10,wallthick+4,2,1,9,"vertical");
                     }
                 }
+                // case floor panel clamp holes
+                translate([150-gap-wallthick,(depth/2)-gap-wallthick,floorthick-adj-.5]) 
+                    panel_clamp("bottom", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                if(rack_width == 19) { 
+                    translate([300-gap-wallthick,(depth/2)-gap-wallthick,floorthick-adj-.5]) 
+                        panel_clamp("bottom", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                }
+                // case upper panel clamp holes
+                translate([150-gap-wallthick,-gap-adj,case_z-13]) 
+                    panel_clamp("rear", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                translate([150-gap-wallthick,depth-gap-(2*wallthick)+adj,
+                    case_z-13]) panel_clamp("front", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                if(rack_width == 19) { 
+                    translate([300-gap-wallthick,-gap-adj,case_z-13]) 
+                        panel_clamp("rear", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                    translate([300-gap-wallthick,depth-gap-(2*wallthick)+adj,
+                        case_z-13]) panel_clamp("front", "m2", "sloped", 6, 18, 5, [true,10,2,"holes"]);
+                }
             }
             // pcb and multi-pcb standoffs
             for(r = [0:len(rack_bay_sbc)-1]) {