<http://schema.org/description>
"&lt;p&gt;The most commonly used\u2014and perhaps the simplest\u2014measure of surface finish is the Ra parameter, or roughness average.  But like ordering a coffee at one of today\u2019s deluxe cafes, it\u2019s not exactly simple. &lt;/p&gt;"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mmsonline.com/columns/skids-and-probes-for-surface-finish>