About: http://webisa.webdatacommons.org/11021028

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Preferably, the inner portion 240 comprises a drillable material such as aluminum, and the support sleeve 235 comprises steel or other composite material of sufficient strength to provide rigidity to the body portion 230.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com