There are two major categories of partials, tissue borne or tooth borne.
Tissue borne partials are primarily acrylic, flexible, thermo-flex or in rare occasions cast snap in partials with or without clasps but not rests and are tissue supported only.
Tooth borne partials are supported with clasps and rests, or precision attachments and are primarily cast frame partials. Made of Chrome alloy, Chrome Cobalt or Titanium material they do not harm your natural dentition or tissue as they are all dental acid resistant alloys.
Cast partials with Precision attachments should be well planned between both the Denturist and Dentist. If abutting teeth are going to be crowned the female lock should be cast in the design of the crown so that male lock can be cast in the partial frame. This of course is all done to eliminate clasps.