diff --git a/src/frontend/flask_app/static/js/dxf_recipe_wizard.js b/src/frontend/flask_app/static/js/dxf_recipe_wizard.js
index 5056ee7..5a5a945 100644
--- a/src/frontend/flask_app/static/js/dxf_recipe_wizard.js
+++ b/src/frontend/flask_app/static/js/dxf_recipe_wizard.js
@@ -21,6 +21,7 @@ function dxfRecipeWizard(taskId, csrf, msgs) {
     imageName: '',
     imageSrc: '',
     dxfFile: null,
+    mmPx: '',              // #98: mm/px a mano (immagine da file), stringa con virgola o punto
     bandMm: 0.1,
     minPointsPct: 95,
     dark: true,            // spuntato = pezzo scuro su fondo chiaro (controluce)
@@ -59,8 +60,19 @@ function dxfRecipeWizard(taskId, csrf, msgs) {
     },
 
     get calibrated() { return this.calState === 'calibrated'; },
+    // #98: mm/px inserito a mano -> px/mm; null se vuoto o fuori da 0.00001..100 (limiti di /camera/calibrazioni/manuale, #95)
+    get manualPxMm() {
+      const raw = String(this.mmPx || '').trim().replace(',', '.');
+      if (!raw) return null;
+      const v = Number(raw);
+      if (!Number.isFinite(v) || v < 0.00001 || v > 100) return null;
+      return 1 / v;
+    },
+    // #98: compilato ma non valido -> errore in pagina
+    get mmPxInvalid() { return String(this.mmPx || '').trim() !== '' && this.manualPxMm === null; },
     get canRun() {
-      return !!(this.stationId && this.calibrated && this.imageFile && this.dxfFile) && !this.busy;
+      // #98: la scala a mano sostituisce la calibrazione della stazione
+      return !!(this.stationId && (this.calibrated || this.manualPxMm !== null) && this.imageFile && this.dxfFile) && !this.busy;
     },
 
     _setImage(file) {
@@ -120,6 +132,8 @@ function dxfRecipeWizard(taskId, csrf, msgs) {
         fd.append('image', this.imageFile, this.imageFile.name || 'capture.png');
         fd.append('dxf', this.dxfFile, this.dxfFile.name);
         fd.append('station_id', this.stationId);
+        // #98: scala a mano; il backend la preferisce alla calibrazione della stazione
+        if (this.manualPxMm !== null) fd.append('px_per_mm', String(this.manualPxMm));
         fd.append('band_mm', String(this.bandMm));
         fd.append('min_points_pct', String(this.minPointsPct));
         fd.append('polarity', this.dark ? 'dark' : 'light');
diff --git a/src/frontend/flask_app/templates/maker/task_editor.html b/src/frontend/flask_app/templates/maker/task_editor.html
index a06fed4..5a7f4c6 100644
--- a/src/frontend/flask_app/templates/maker/task_editor.html
+++ b/src/frontend/flask_app/templates/maker/task_editor.html
@@ -680,13 +680,23 @@
                         <p x-show="stationId && calibrated" class="mt-1 text-xs text-emerald-600">
                           {{ _('Calibrazione') }}: <span x-text="calLabel"></span>
                         </p>
-                        <p x-show="stationId && calState && !calibrated" class="mt-1 text-xs text-amber-600">
+                        <p x-show="stationId && calState && !calibrated && manualPxMm === null" class="mt-1 text-xs text-amber-600">{# #98: nascosto con mm/px valido #}
                           <span x-text="calState === 'uncalibrated' ? {{ _('Stazione non calibrata: calibrala prima di creare la ricetta.')|tojson_attr }} : {{ _('Acquisitore non raggiungibile: impossibile leggere la calibrazione.')|tojson_attr }}"></span>
                           <a :href="calUrl" target="_blank" rel="noopener" x-show="calUrl"
                              class="font-medium text-primary hover:underline">{{ _('Calibra') }}</a>
                           <span class="text-[var(--text-muted)]">({{ _('oppure vedi la pagina Stazioni') }})</span>
                         </p>
                       </div>
+                      <!-- #98: mm/px a mano per immagini da file, sostituisce la calibrazione della stazione -->
+                      <div>
+                        <label class="tmf-label text-xs">{{ _('mm/px (immagine da file)') }}</label>
+                        <input type="text" inputmode="decimal" class="tmf-input text-xs" x-model="mmPx" placeholder="0,01406">
+                        <p x-show="manualPxMm !== null" class="mt-1 text-xs text-emerald-600">
+                          = <span x-text="fmt(manualPxMm)"></span> px/mm
+                        </p>
+                        <p x-show="mmPxInvalid" class="mt-1 text-xs text-amber-600">{{ _('mm/px non valido') }}</p>
+                        <p class="mt-1 text-xs text-[var(--text-muted)]">{{ _('Se compilato sostituisce la calibrazione della stazione; la scala resta salvata nella ricetta.') }}</p>
+                      </div>
                       <!-- Immagine: camera o file -->
                       <div class="grid grid-cols-1 sm:grid-cols-2 gap-3">
                         <div>
diff --git a/src/frontend/flask_app/tests/test_dxf_recipe_routes.py b/src/frontend/flask_app/tests/test_dxf_recipe_routes.py
index a1cebe8..c9b85d3 100644
--- a/src/frontend/flask_app/tests/test_dxf_recipe_routes.py
+++ b/src/frontend/flask_app/tests/test_dxf_recipe_routes.py
@@ -178,6 +178,12 @@ class TestDxfCompareProxy:
         assert set(kwargs["files"]) == {"image", "dxf"}
         assert kwargs["files"]["image"][1] == PNG
 
+    def test_manual_px_per_mm_forwarded(self, logged_in_client, mock_api_client):
+        # #98: scala a mano dal wizard (immagine da file): inoltrata al backend
+        mock_api_client.post.return_value = self.OK
+        self._post(logged_in_client, station_id="4", px_per_mm="71.1237")
+        assert mock_api_client.post.call_args.kwargs["data"]["px_per_mm"] == "71.1237"
+
     def test_save_true_forwarded(self, logged_in_client, mock_api_client):
         mock_api_client.post.return_value = {**self.OK, "saved": True, "recipe_dir": "vision/recipes/7/x"}
         resp = self._post(logged_in_client, save="true")
@@ -229,4 +235,5 @@ class TestPages:
         assert "js/dxf_recipe_wizard.js" in html
         assert "dxfRecipeWizard(" in html
         assert "@dxf-recipe-saved" in html
+        assert 'x-model="mmPx"' in html  # #98: campo mm/px a mano
         assert "Pezzo scuro su fondo chiaro" in html or "Dark part on light" in html