Ladder 05: UNC, UNF, Rc and NPT tapped holes, each drilled to its tap maker's drill

1/4-20 UNC (#7, 0.201 in) and Rc 1/2 (17.6) through the stock, 1/4-28 UNF (5.45) blind with a flat floor, 1/4-18 NPT (10.85) through: a cosmetic thread in a straight hole, so each volume is the stock less that cylinder. The drills are the catalogue's (Guhring, Yamawa YEU23); each method gives the standard's minor diameter beside it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-04 19:15:57 +00:00 · 2026-10-29 17:40:57 -04:00
parent 22cd8e74f6
commit 4879144271
10 changed files with 130 additions and 1 deletions
@@ -0,0 +1,9 @@
+{
+ "sources": [],
+ "what": "a 1/4-20 UNC tapped hole through the stock: drilled #7 (0.201 in), cosmetic thread",
+ "source": "analytic",
+ "method": "ASME B1.1 1/4-20 UNC: D = 0.25 in, P = 1/20 in, basic minor D1 = D - 1.082532 P = 0.1959 in; the tap drill is #7, 0.201 in = 5.1054 mm (the cutting-tap drill for about 75% thread, Guhring's table in thread_catalog.rs); removed pi 2.5527^2 20; the cosmetic thread adds no geometry: + one cylinder face",
+ "body_count": 1,
+ "volume_mm3": 47590.57022274,
+ "faces": 7
+}
@@ -0,0 +1,16 @@
+{
+ "base": "../../01-primitives/001-box",
+ "commands": [
+  {
+   "command": "solid.hole",
+   "params": {
+    "position": [
+     30,
+     20,
+     20
+    ],
+    "thread": "1/4-20 UNC"
+   }
+  }
+ ]
+}
@@ -0,0 +1,9 @@
+{
+ "sources": [],
+ "what": "a 1/4-28 UNF tapped blind hole 10 deep, flat bottom: drilled 5.45 mm, cosmetic thread",
+ "source": "analytic",
+ "method": "ASME B1.1 1/4-28 UNF: D = 0.25 in, P = 1/28 in, basic minor D1 = D - 1.082532 P = 5.368 mm; the tap maker's drill 5.45 mm (Guhring, thread_catalog.rs), above D1 as a drill must be; removed pi 2.725^2 10; + wall and floor",
+ "body_count": 1,
+ "volume_mm3": 47766.717110517,
+ "faces": 8
+}
@@ -0,0 +1,17 @@
+{
+ "base": "../../01-primitives/001-box",
+ "commands": [
+  {
+   "command": "solid.hole",
+   "params": {
+    "position": [
+     30,
+     20,
+     20
+    ],
+    "thread": "1/4-28 UNF",
+    "depth": 10
+   }
+  }
+ ]
+}
@@ -0,0 +1,9 @@
+{
+ "sources": [],
+ "what": "an Rc 1/2 tapped hole through the stock (ISO 7-1 internal taper): a straight hole at the tap maker's 17.6 mm, cosmetic thread",
+ "source": "analytic",
+ "method": "ISO 7-1 Rc 1/2: gauge diameter d = 20.955 at the face, 14 threads per inch, h = 0.640327 P, minor d1 = d - 2h = 18.631 there and 1/16 smaller per mm deeper (18.631 - 13.2/16 = 17.806 at the end of the 13.2 mm useful thread); a straight (not reamed) hole takes the tap maker's 17.6 (Yamawa YEU23 p.709, the largest for non-full threads): removed pi 8.8^2 20; + one cylinder face",
+ "body_count": 1,
+ "volume_mm3": 43134.30129812,
+ "faces": 7
+}
@@ -0,0 +1,16 @@
+{
+ "base": "../../01-primitives/001-box",
+ "commands": [
+  {
+   "command": "solid.hole",
+   "params": {
+    "position": [
+     30,
+     20,
+     20
+    ],
+    "thread": "Rc 1/2"
+   }
+  }
+ ]
+}
@@ -0,0 +1,9 @@
+{
+ "sources": [],
+ "what": "a 1/4-18 NPT tapped hole through the stock (ASME B1.20.1): a straight hole at the tap maker's 10.85 mm, cosmetic thread",
+ "source": "analytic",
+ "method": "ASME B1.20.1 1/4-18 NPT: E0 = 0.47739 in, L1 = 0.2278 in, h = 0.8 P; at the face the minor E1 - h = 0.48163 - 0.04444 in = 11.105 mm, 1/16 smaller per mm deeper; a straight hole takes the tap maker's 10.85 (Yamawa YEU23 p.710): removed pi 5.425^2 20; + one cylinder face",
+ "body_count": 1,
+ "volume_mm3": 46150.819294189,
+ "faces": 7
+}
@@ -0,0 +1,16 @@
+{
+ "base": "../../01-primitives/001-box",
+ "commands": [
+  {
+   "command": "solid.hole",
+   "params": {
+    "position": [
+     30,
+     20,
+     20
+    ],
+    "thread": "1/4-18 NPT"
+   }
+  }
+ ]
+}
@@ -91,7 +91,11 @@
        "ladder/05-holes-and-taps/011-crossing-holes-steinmetz",
        "ladder/05-holes-and-taps/012-crossing-tapped-holes-offset",
        "ladder/05-holes-and-taps/008-tapped-m5-into-curved-face",
-        "ladder/05-holes-and-taps/013-part-holes"
+        "ladder/05-holes-and-taps/013-part-holes",
+        "ladder/05-holes-and-taps/014-tapped-1-4-20-unc-through",
+        "ladder/05-holes-and-taps/015-tapped-1-4-28-unf-blind",
+        "ladder/05-holes-and-taps/016-tapped-rc-1-2-through",
+        "ladder/05-holes-and-taps/017-tapped-1-4-npt-through"
      ],
      "tier": "05-holes-and-taps",
      "what": "holes and tapped holes"
@@ -568,6 +568,30 @@ case(T5, "013-part-holes", "the running part: an M6 tapped through hole, an M5 t
     {"body_count": 1, "volume_mm3": V5, "faces": 20},
     "removed pi 2.5^2 20 (M6, tap drill 5) + pi 2.1^2 8 (M5, tap drill 4.2, flat) + pi 1.65^2 35; faces +1 +2 +1", base=C4)
 C5 = up(T5, "013-part-holes")
+# Tapped holes of the other catalogued families: cosmetic threads in a hole drilled to the tap
+# maker's drill (crates/doc/src/thread_catalog.rs), so a drilled cylinder is all the geometry.
+case(T5, "014-tapped-1-4-20-unc-through", "a 1/4-20 UNC tapped hole through the stock: drilled #7 (0.201 in), cosmetic thread",
+     [H(position=top, thread="1/4-20 UNC")],
+     {"body_count": 1, "volume_mm3": VB - PI * (0.201 * 25.4 / 2) ** 2 * 20, "faces": 7},
+     "ASME B1.1 1/4-20 UNC: D = 0.25 in, P = 1/20 in, basic minor D1 = D - 1.082532 P = 0.1959 in; the tap drill is #7, 0.201 in = 5.1054 mm "
+     "(the cutting-tap drill for about 75% thread, Guhring's table in thread_catalog.rs); removed pi 2.5527^2 20; the cosmetic thread adds no geometry: + one cylinder face", base=B1)
+case(T5, "015-tapped-1-4-28-unf-blind", "a 1/4-28 UNF tapped blind hole 10 deep, flat bottom: drilled 5.45 mm, cosmetic thread",
+     [H(position=top, thread="1/4-28 UNF", depth=10)],
+     {"body_count": 1, "volume_mm3": VB - PI * 2.725 ** 2 * 10, "faces": 8},
+     "ASME B1.1 1/4-28 UNF: D = 0.25 in, P = 1/28 in, basic minor D1 = D - 1.082532 P = 5.368 mm; the tap maker's drill 5.45 mm (Guhring, thread_catalog.rs), "
+     "above D1 as a drill must be; removed pi 2.725^2 10; + wall and floor", base=B1)
+case(T5, "016-tapped-rc-1-2-through", "an Rc 1/2 tapped hole through the stock (ISO 7-1 internal taper): a straight hole at the tap maker's 17.6 mm, cosmetic thread",
+     [H(position=top, thread="Rc 1/2")],
+     {"body_count": 1, "volume_mm3": VB - PI * 8.8 ** 2 * 20, "faces": 7},
+     "ISO 7-1 Rc 1/2: gauge diameter d = 20.955 at the face, 14 threads per inch, h = 0.640327 P, minor d1 = d - 2h = 18.631 there and 1/16 smaller per mm deeper "
+     "(18.631 - 13.2/16 = 17.806 at the end of the 13.2 mm useful thread); a straight (not reamed) hole takes the tap maker's 17.6 (Yamawa YEU23 p.709, the largest for "
+     "non-full threads): removed pi 8.8^2 20; + one cylinder face", base=B1)
+case(T5, "017-tapped-1-4-npt-through", "a 1/4-18 NPT tapped hole through the stock (ASME B1.20.1): a straight hole at the tap maker's 10.85 mm, cosmetic thread",
+     [H(position=top, thread="1/4-18 NPT")],
+     {"body_count": 1, "volume_mm3": VB - PI * 5.425 ** 2 * 20, "faces": 7},
+     "ASME B1.20.1 1/4-18 NPT: E0 = 0.47739 in, L1 = 0.2278 in, h = 0.8 P; at the face the minor E1 - h = 0.48163 - 0.04444 in = 11.105 mm, 1/16 smaller per mm deeper; "
+     "a straight hole takes the tap maker's 10.85 (Yamawa YEU23 p.710): removed pi 5.425^2 20; + one cylinder face", base=B1)
+
 # ---------------------------------------------------------------- 06 threads
 def thr(face, **p):
    return C("solid.thread", face=face, modeled=True, **p)