Abstract: A plug-and-seat valve plug head assembly that resists abrasive erosion includes a hardened plug head, such as a ceramic plug head, attached to a plug stem without any soldering, welding, or braising attachment to the plug head. A diameter of a second portion of the plug head smoothly increases according to a plug diameter profile. A diameter of a first portion of the plug head is everywhere smaller than the plug diameter profile, and is maximal at a location spaced apart from the second portion. A plug head retainer overlaps and closely conforms to the first portion, while presenting an exterior surface that smoothly continues and extends the plug diameter profile. In embodiments, a plug head retainer blank attaches to the plug head retainer, capturing the plug head therebetween. Embodiments apply radial and/or axial stress to the plug head.