Nape piercing
Somewhat less common are surface anchors, commonly made from surgical implant-grade titanium. A surface anchor has two parts: a base or foot which is inserted under the dermis during the piercing process and which incorporates a stem exposed to the surface, and a decorative disc or ball of jewelry which typically appears flush with the surface of the skin. Surface anchor nape piercings are most commonly found placed symmetrically on either side of the spine at the nape.
Offshore embedded anchors
Anchor piles are hollow steel pipes that are either driven or drilled and grouted into the seabed, similar to pile foundations commonly used in offshore fixed structures. The figure shows the different installation methods whereby the driven steel tube is driven mechanically by a driving hammer, whilst the cast in-situ grouted pile is inserted into an oversize borehole constructed from a rotary drill and subsequently grouted in cement. Both methods are commonly used offshore depending on the geophysical and geotechnical properties of the seabed.