<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Crossfire by Rivet Software version 4.2.117.0 http://www.rivetsoftware.com-->
<!--Based on XBRL 2.1-->
<!--Created on: 11/10/2011 4:38:19 PM-->
<!--Modified on: 11/10/2011 4:38:19 PM-->
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" targetNamespace="http://www.gopresto.com/20111002" elementFormDefault="qualified" attributeFormDefault="unqualified" xmlns:npk="http://www.gopresto.com/20111002" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:us-types="http://fasb.org/us-types/2011-01-31">
  <annotation>
    <appinfo>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/StatementConsolidatedBalanceSheets" id="StatementConsolidatedBalanceSheets">
        <link:definition>00100 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/StatementConsolidatedStatementsOfEarnings" id="StatementConsolidatedStatementsOfEarnings">
        <link:definition>00200 - Statement - Consolidated Statements Of Earnings</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/StatementConsolidatedStatementsOfCashFlows" id="StatementConsolidatedStatementsOfCashFlows">
        <link:definition>00300 - Statement - Consolidated Statements Of Cash Flows</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DocumentDocumentAndEntityInformation" id="DocumentDocumentAndEntityInformation">
        <link:definition>00090 - Document - Document And Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/StatementConsolidatedBalanceSheetsParenthetical" id="StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>00105 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureEarningsPerShare" id="DisclosureEarningsPerShare">
        <link:definition>10101 - Disclosure - Earnings Per Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureReclassifications" id="DisclosureReclassifications">
        <link:definition>10201 - Disclosure - Reclassifications</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureBusinessSegments" id="DisclosureBusinessSegments">
        <link:definition>10301 - Disclosure - Business Segments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureFairValueOfFinancialInstruments" id="DisclosureFairValueOfFinancialInstruments">
        <link:definition>10401 - Disclosure - Fair Value Of Financial Instruments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureCashCashEquivalentsAndMarketableSecurities" id="DisclosureCashCashEquivalentsAndMarketableSecurities">
        <link:definition>10501 - Disclosure - Cash, Cash Equivalents And Marketable Securities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureCommitmentsAndContingencies" id="DisclosureCommitmentsAndContingencies">
        <link:definition>10601 - Disclosure - Commitments And Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureAccumulatedOtherComprehensiveIncome" id="DisclosureAccumulatedOtherComprehensiveIncome">
        <link:definition>10701 - Disclosure - Accumulated Other Comprehensive Income</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureAdoptionOfNewAccountingStandards" id="DisclosureAdoptionOfNewAccountingStandards">
        <link:definition>10801 - Disclosure - Adoption Of New Accounting Standards</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.gopresto.com/2010-09-30/role/DisclosureSubsequentEvent" id="DisclosureSubsequentEvent">
        <link:definition>10901 - Disclosure - Subsequent Event</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:type="simple" xlink:href="npk-20111002_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Presentation Links, all" />
      <link:linkbaseRef xlink:type="simple" xlink:href="npk-20111002_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Label Links, all" />
      <link:linkbaseRef xlink:type="simple" xlink:href="npk-20111002_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Calculation Links, all" />
    </appinfo>
  </annotation>
  <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
  <import namespace="http://fasb.org/us-gaap/2011-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd" />
  <import namespace="http://xbrl.sec.gov/dei/2011-01-31" schemaLocation="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd" />
  <import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
  <import namespace="http://www.xbrl.org/dtr/type/numeric" schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" />
  <element id="npk_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <element id="npk_ReclassificationsAbstract" name="ReclassificationsAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <element id="npk_CashDividendsDeclaredAndPaid" name="CashDividendsDeclaredAndPaid" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="npk_AccumulatedOtherComprehensiveIncomeAbstract" name="AccumulatedOtherComprehensiveIncomeAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
</schema>