X-Git-Url: https://git.distorted.org.uk/~mdw/dep-ui/blobdiff_plain/c3d1ecfbbc2666352aadcb2a584ee0abde161df9..d9941e5e6acf02920355cf86b11fbdd9096b102a:/rolling.html

diff --git a/rolling.html b/rolling.html
index 14e337f..dde5168 100644
--- a/rolling.html
+++ b/rolling.html
@@ -141,8 +141,6 @@
 <script type="text/javascript"><!--
 	DEP_UI.add_elt_class(DEP_UI.elt('help'), 'conceal');
 --></script>
-<h2>What this program does</h2>
-
 <div id=js-note>
 <script type="text/javascript"><!--
 	DEP_UI.add_elt_class(DEP_UI.elt('js-note'), 'conceal');
@@ -153,7 +151,7 @@ well.  It only requires first-party scripts;
 see <a href="#privacy">Privacy</a> for more details.
 </div>
 
-<h3>Background</h3>
+<h2>Background</h2>
 
 <p>When you pass round or square wire through flat rolls it gets flatter
 and longer, but it also gets wider.  You can exploit this to make thin
@@ -173,11 +171,16 @@ of it you need to create the required starting size that you can then
 roll down to the required thickness of strip.
 
 <p>For best results, roll the strip in as few passes as you can handle.
+The results aren&rsquo;t accurate for broad, thin strips.
+Width-to-thickness ratios of up to 6:1 are known to be good; ratios of
+12:1 or more don't work: strips don&rsquo;t get as wide as predicted by
+our model.  We need to collect more data and construct a better model to
+handle this case properly.
 
 <p>You can see the <a href="rolling-eqn.html">detailed equations</a>
 used for this calculation if you&rsquo;re interested.
 
-<h3>Use</h3>
+<h2>Use</h2>
 
 <p>Boxes with light red or white backgrounds are entry boxes for you to
 type in your requirements; boxes with dark red or grey backgrounds are
@@ -200,7 +203,7 @@ will be in millimetres; if you use inches, the results will be in
 inches.  Whatever you use, the results are displayed to only 3 decimal
 places.
 
-<h3>Code and credits</h3>
+<h2>Code and credits</h2>
 
 <p>The code which makes this page work
 is <a href="https://www.gnu.org/philosophy/free-sw.html">free
@@ -219,7 +222,7 @@ patches</a>.
 the text was written by Mark Wooding and Gary Wooding.  The data used
 to derive the computation was provided by Gary Wooding.
 
-<h3 id="privacy">Privacy</h3>
+<h2 id="privacy">Privacy</h2>
 
 <p>There are no cookies or other trackers here.  This page does not use
 externally hosted scripts, fonts, images, or anything else.  The server