Occasionally tapped threads strip and a larger screw is inappropriate. Lag screws are particularly vulnerable, as only one cortex is available on tapping. A cortical nut manufactured from implant grade nylon can give the screw purchase to allow normal tightening. The thread form is designed to grip the screw to minimize backing out. Sterile.
Revision date indicates the date the MSDS or SDS was last revised. MSDS / SDS are
dated when they are originally issued AND when any significant change has been made
to the chemical compound or research has revealed a health or physical hazard different
from what was originally stated.