<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31371890</termId><termName>surface hardening</termName><termType>PT</termType><termNote><![CDATA[ Hardening the surface of a metal by case-hardening or other method, such as by induction or flame. ]]></termNote><termCreatedDate>2026-03-30 20:40:17</termCreatedDate><relation><relationType>UF</relationType><termId>31371891</termId><termName>hardening, surface</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31371892</termId><termName>surface hardened</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31340974</termId><termName>metal finishing processes and techniques</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31410348</termId><termName>case-hardening</termName><termType>PT</termType></relation></term>  </Zthes>