diff --git a/readme.md b/readme.md
index f007079..41c4e61 100644
--- a/readme.md
+++ b/readme.md
@@ -1131,14 +1131,15 @@ KP pillow block bearings
 | ---:|:--- |:---|
 |   1 | ```kp_pillow_block(KP000)``` |  KP000 pillow block |
 |   1 | ```kp_pillow_block(KP001)``` |  KP001 pillow block |
-|   1 | ```kp_pillow_block(KP08_15)``` |  KP08 pillow block (15mm variant)|
-|   1 | ```kp_pillow_block(KP08_18)``` |  KP08 pillow block (18mm variant)|
+|   1 | ```kp_pillow_block(KP08_15)``` |  KP08_15 pillow block |
+|   1 | ```kp_pillow_block(KP08_18)``` |  KP08_18 pillow block |
+|   2 | ```sliding_t_nut(M4_hammer_nut)``` |  Nut M4 hammer |
 |   2 | ```sliding_t_nut(M4_sliding_t_nut)``` |  Nut M4 sliding T |
 |   2 | ```sliding_t_nut(M5_sliding_t_nut)``` |  Nut M5 sliding T |
 |   2 | ```nut(M5_nut, nyloc = undef)``` |  Nut M5 x 4mm  |
-|   2 | ```screw(M4_cap_screw, 10)``` |  Screw M4 cap x 10mm |
+|   4 | ```screw(M4_cap_screw, 10)``` |  Screw M4 cap x 10mm |
 |   4 | ```screw(M5_cap_screw, 12)``` |  Screw M5 cap x 12mm |
-|   2 | ```washer(M4_washer)``` |  Washer  M4 x 9mm x 0.8mm |
+|   4 | ```washer(M4_washer)``` |  Washer  M4 x 9mm x 0.8mm |
 |   6 | ```washer(M5_washer)``` |  Washer  M5 x 10mm x 1mm |
 
 
diff --git a/tests/kp_pillow_blocks.scad b/tests/kp_pillow_blocks.scad
index 0a127df..39f14d8 100644
--- a/tests/kp_pillow_blocks.scad
+++ b/tests/kp_pillow_blocks.scad
@@ -23,12 +23,12 @@ include <../vitamins/kp_pillow_blocks.scad>
 include <../vitamins/nuts.scad>
 
 module kp_pillow_blocks() {
-    screws = [M4_cap_screw, M5_cap_screw, M5_cap_screw];
-    nuts = [M4_sliding_t_nut, M5_sliding_t_nut, M5_nut];
+    screws = [M4_cap_screw, M4_cap_screw, M5_cap_screw, M5_cap_screw];
+    nuts = [M4_sliding_t_nut, M4_hammer_nut, M5_sliding_t_nut, M5_nut];
+    assert(len(screws) == len(kp_pillow_blocks) && len(nuts) == len(kp_pillow_blocks));
     layout([for(k = kp_pillow_blocks) 2 * kp_size(k)[1]])
         kp_pillow_block_assembly(kp_pillow_blocks[$i], screw_type = screws[$i], nut_type = nuts[$i]);
 }
 
 if($preview)
     kp_pillow_blocks();
-
diff --git a/tests/png/kp_pillow_blocks.png b/tests/png/kp_pillow_blocks.png
index ed1a826..3fa3ca0 100644
Binary files a/tests/png/kp_pillow_blocks.png and b/tests/png/kp_pillow_blocks.png differ