{"id":30602,"date":"2026-03-30T03:33:15","date_gmt":"2026-03-30T03:33:15","guid":{"rendered":"https:\/\/hardnesstests.com\/?p=30602"},"modified":"2026-03-30T03:33:16","modified_gmt":"2026-03-30T03:33:16","slug":"knoop-hardness-test-a-comprehensive-technical-guide","status":"publish","type":"post","link":"https:\/\/hardnesstests.com\/es\/knoop-hardness-test-a-comprehensive-technical-guide\/","title":{"rendered":"Knoop Hardness Test: A Comprehensive Technical Guide"},"content":{"rendered":"<h2 class=\"wp-block-heading\" id=\"h-introduction-to-the-knoop-hardness-test\">Introduction to the Knoop Hardness Test<\/h2>\n\n\n\n<p>En <strong>Knoop hardness test<\/strong>\u200b is a micro-indentation hardness testing method primarily used to measure the hardness of brittle materials, thin films, and small, delicate components. Developed in 1939 by Frederick Knoop and colleagues at the National Bureau of Standards (now NIST), this test was specifically designed to address the limitations of existing hardness tests\u2014such as Brinell and Rockwell\u2014when applied to materials like glass, ceramics, and gemstones.<\/p>\n\n\n\n<p>Unlike macro-hardness tests that use large indenters and high loads, the Knoop test employs a <strong>rhombic diamond indenter<\/strong>\u200b and relatively light loads (typically 10 gf to 1000 gf). This produces a shallow, elongated indentation that minimizes cracking in brittle materials and allows for localized hardness measurement without damaging the specimen.<\/p>\n\n\n\n<p>Today, the Knoop test is standardized under <strong>ASTM E384<\/strong>\u200b (Standard Test Method for Microindentation Hardness of Materials) and remains a critical tool in materials science, particularly for characterizing ceramics, glasses, thin films, and coated surfaces.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-historical-development-and-purpose\">Historical Development and Purpose<\/h2>\n\n\n\n<p>Before the Knoop test, hardness testing relied heavily on macro-scale methods:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ensayo de dureza Brinell<\/strong>\u200b (1900): Used a spherical indenter and high loads (500\u20133000 kgf), unsuitable for brittle materials.<\/li>\n\n\n\n<li><strong>Ensayo de dureza Rockwell<\/strong>\u200b (1919): Employed conical or ball indenters with moderate loads, but still too aggressive for small or fragile specimens.<\/li>\n\n\n\n<li><strong>Ensayo de dureza Vickers<\/strong>\u200b (1921): Introduced a pyramidal diamond indenter, improving precision but still generating relatively large indentations.<\/li>\n<\/ul>\n\n\n\n<p>The Knoop test emerged from the need to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Measure hardness on <strong>brittle materials<\/strong>\u200b without inducing fracture.<\/li>\n\n\n\n<li>Characterize <strong>thin films and coatings<\/strong>\u200b without substrate interference.<\/li>\n\n\n\n<li>Perform <strong>micro-scale hardness mapping<\/strong>\u200b for material research.<\/li>\n<\/ul>\n\n\n\n<p>By using a lighter load and an elongated indenter, the Knoop test produces a shallow indentation with minimal lateral cracking, making it ideal for fragile or micro-structured materials.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-principle-of-the-knoop-hardness-test\">Principle of the Knoop Hardness Test<\/h2>\n\n\n\n<p>The Knoop hardness test operates on the same fundamental principle as other indentation hardness tests: <strong>a hard indenter is pressed into the material under a specific load, and the size of the resulting impression is measured to calculate hardness.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" src=\"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1.jpg\" alt=\"\" class=\"wp-image-30145\" srcset=\"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1.jpg 800w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-300x300.jpg 300w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-150x150.jpg 150w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-768x768.jpg 768w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-12x12.jpg 12w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-400x400.jpg 400w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/PCHBST-3000Z\u5d4c\u5165\u5f0f\u96c6\u6210\u667a\u80fd\u89c6\u89c9\u5e03\u6c0f\u786c\u5ea6\u8ba1-700x700.jpg 700w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-key-steps-in-the-test-process\">Key Steps in the Test Process<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Indentation<\/strong>: A rhombic diamond indenter is pressed into the polished specimen surface under a predefined load.<\/li>\n\n\n\n<li><strong>Holding<\/strong>: The load is maintained for a specified dwell time (usually 10\u201315 seconds).<\/li>\n\n\n\n<li><strong>Unloading<\/strong>: The load is removed, leaving a permanent indentation.<\/li>\n\n\n\n<li><strong>Medici\u00f3n<\/strong>: The long diagonal of the indentation is measured optically.<\/li>\n\n\n\n<li><strong>Calculation<\/strong>: Knoop hardness is calculated using a formula based on the indentation geometry.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-the-knoop-indenter-geometry\">The Knoop Indenter Geometry<\/h2>\n\n\n\n<p>The Knoop indenter is a precisely ground <strong>rhombic-based pyramid<\/strong>\u200b made of diamond. Its unique geometry creates an elongated, shallow indentation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-geometric-characteristics\">Geometric Characteristics<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Face angles<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Two opposite edges: <strong>172.5\u00b0<\/strong><\/li>\n\n\n\n<li>Other two opposite edges: <strong>130\u00b0<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Resulting indentation shape<\/strong>: A long, narrow rhombus.<\/li>\n\n\n\n<li><strong>Depth-to-diagonal ratio<\/strong>: Approximately <strong>1:30<\/strong>, meaning the indentation is very shallow relative to its length.<\/li>\n<\/ul>\n\n\n\n<p>This elongated shape ensures:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Minimal penetration depth.<\/li>\n\n\n\n<li>Reduced stress concentration.<\/li>\n\n\n\n<li>Lower likelihood of crack formation in brittle materials.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-knoop-hardness-number-khn-calculation\">Knoop Hardness Number (KHN) Calculation<\/h2>\n\n\n\n<p>The Knoop Hardness Number (KHN) is defined as the ratio of the applied load to the projected area of the indentation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-formula\">Formula<\/h3>\n\n\n\n<pre class=\"wp-block-preformatted\">KHN=Ap\u200bP\u200b<\/pre>\n\n\n\n<p>D\u00f3nde:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>P= Applied load (kgf)<\/li>\n\n\n\n<li>Ap\u200b= Projected area of the indentation (mm\u00b2)<\/li>\n<\/ul>\n\n\n\n<p>The projected area is calculated from the long diagonal length (d, in mm):<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">Ap\u200b=2\u22c5tan(86.25\u2218)\u22c5tan(65\u2218)d2\u200b\u224830.573d2\u200b<\/pre>\n\n\n\n<p>Thus, the simplified formula becomes:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">KHN\u2248(30.573d2\u200b)P\u200b=d230.573\u22c5P\u200b<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-example-calculation\">Example Calculation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Applied load: P=0.1kgf<\/li>\n\n\n\n<li>Measured long diagonal: d=0.12mm<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\">KHN=(0.12)230.573\u00d70.1\u200b=0.01443.0573\u200b\u2248212<\/pre>\n\n\n\n<p>So, the Knoop hardness value is reported as <strong>KHN 212<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-standard-test-procedure-astm-e384\">Standard Test Procedure (ASTM E384)<\/h2>\n\n\n\n<p>Following standardized procedures ensures consistency, accuracy, and comparability of results.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-1-specimen-preparation\">1. Specimen Preparation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Surface must be <strong>flat, smooth, and polished<\/strong>\u200b (typically 1 \u00b5m finish).<\/li>\n\n\n\n<li>Specimen thickness should be sufficient to prevent substrate influence (at least <strong>10\u00d7 the indentation depth<\/strong>).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-2-indenter-and-microscope-calibration\">2. Indenter and Microscope Calibration<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Verify indenter geometry and optical measurement system accuracy.<\/li>\n\n\n\n<li>Calibrate the microscope using certified standards.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-3-load-application\">3. Load Application<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Select an appropriate load (commonly 10 gf \u2013 1000 gf).<\/li>\n\n\n\n<li>Apply the load smoothly without shock or vibration.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-4-dwell-time\">4. Dwell Time<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Typically <strong>10\u201315 seconds<\/strong>, as specified by the standard or application requirement.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-5-measurement\">5. Measurement<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Measure the long diagonal (d) optically with a calibrated microscope.<\/li>\n\n\n\n<li>Take multiple measurements (usually 5\u201310) and compute the average KHN.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-comparison-with-vickers-and-other-hardness-tests\">Comparison with Vickers and Other Hardness Tests<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Knoop<\/th><th>Vickers<\/th><th>Brinell<\/th><th>Rockwell<\/th><\/tr><\/thead><tbody><tr><td>Indenter Shape<\/td><td>Rhombic pyramid<\/td><td>Square pyramid<\/td><td>Spherical<\/td><td>Conical\/Ball<\/td><\/tr><tr><td>Typical Load<\/td><td>10\u20131000 gf<\/td><td>1\u2013120 kgf<\/td><td>500\u20133000 kgf<\/td><td>60\u2013150 kgf<\/td><\/tr><tr><td>Indentation Size<\/td><td>Small, shallow<\/td><td>Small<\/td><td>Large<\/td><td>Small<\/td><\/tr><tr><td>Best For<\/td><td>Brittle materials, thin films<\/td><td>General purpose<\/td><td>Metales blandos<\/td><td>Production testing<\/td><\/tr><tr><td>Cracking Risk<\/td><td>Low<\/td><td>Moderate<\/td><td>High<\/td><td>Moderate<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-key-advantages-over-vickers\">Key Advantages Over Vickers<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Shallower indentation \u2192 less cracking in brittle materials.<\/li>\n\n\n\n<li>Better suited for <strong>thin films and coatings<\/strong>.<\/li>\n\n\n\n<li>More accurate for materials with <strong>anisotropic hardness<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-applications-of-the-knoop-hardness-test\">Applications of the Knoop Hardness Test<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-1-ceramics-and-glass\">1. Ceramics and Glass<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Measuring hardness of technical ceramics, glass, and gemstones.<\/li>\n\n\n\n<li>Evaluating surface treatments and strengthening processes.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-2-thin-films-and-coatings\">2. Thin Films and Coatings<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Hardness profiling of PVD\/CVD coatings.<\/li>\n\n\n\n<li>Determining coating-substrate composite hardness.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-3-metals-and-alloys\">3. Metals and Alloys<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Microstructural hardness mapping (e.g., carbides in steel).<\/li>\n\n\n\n<li>Studying heat-affected zones and case hardening.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"450\" height=\"800\" src=\"https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-450x800.jpg\" alt=\"\" class=\"wp-image-30435\" srcset=\"https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-450x800.jpg 450w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-169x300.jpg 169w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-7x12.jpg 7w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-700x1244.jpg 700w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72-150x267.jpg 150w, https:\/\/hardnesstests.com\/wp-content\/uploads\/2026\/02\/72.jpg 720w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-4-geological-and-archaeological-samples\">4. Geological and Archaeological Samples<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Mineral identification via hardness.<\/li>\n\n\n\n<li>Non-destructive analysis of artifacts.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-5-quality-control-and-research\">5. Quality Control and Research<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Validating surface modification processes.<\/li>\n\n\n\n<li>Correlating hardness with wear, erosion, or fracture resistance.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-advantages-and-limitations\">Advantages and Limitations<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-advantages\">Ventajas<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Minimal damage to brittle materials.<\/li>\n\n\n\n<li>High spatial resolution (ideal for microstructures).<\/li>\n\n\n\n<li>Suitable for thin films and small components.<\/li>\n\n\n\n<li>Low risk of crack initiation.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-limitations\">Limitations<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Requires highly polished surfaces.<\/li>\n\n\n\n<li>Manual measurement can introduce operator error.<\/li>\n\n\n\n<li>Not suitable for very thick or soft materials.<\/li>\n\n\n\n<li>Less common in industrial production compared to Rockwell\/Vickers.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-best-practices-for-accurate-results\">Best Practices for Accurate Results<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Utilice <strong>consistent load and dwell time<\/strong>.<\/li>\n\n\n\n<li>Ensure <strong>proper surface preparation<\/strong>.<\/li>\n\n\n\n<li>Mantener <strong>calibrated equipment<\/strong>.<\/li>\n\n\n\n<li>Avoid edge effects (indent \u2265 2\u20133\u00d7 diagonal length from edges).<\/li>\n\n\n\n<li>Average multiple indentations to reduce statistical error.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-future-developments\">Future Developments<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Automated image analysis<\/strong>\u200b for faster, more repeatable measurements.<\/li>\n\n\n\n<li><strong>Nanoindentation hybrid systems<\/strong>\u200b combining Knoop and depth-sensing methods.<\/li>\n\n\n\n<li><strong>AI-assisted hardness mapping<\/strong>\u200b for microstructure characterization.<\/li>\n\n\n\n<li>Integration with <strong>digital twin and materials database platforms<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-conclusion\">Conclusi\u00f3n<\/h2>\n\n\n\n<p>The Knoop hardness test remains a vital micro-indentation technique for evaluating the hardness of brittle, thin, or delicate materials where traditional macro-hardness tests fail. Its shallow, elongated indentation minimizes cracking and preserves sample integrity, making it indispensable in ceramics, thin films, coatings, and precision materials research.<\/p>\n\n\n\n<p>By adhering to standardized procedures such as ASTM E384 and leveraging modern automation, engineers and researchers can obtain accurate, repeatable Knoop hardness data essential for material selection, process validation, and quality assurance.<\/p>\n\n\n\n<p>For high-precision Knoop hardness testing equipment and calibration services, consult specialized materials testing providers who adhere to international standards and offer traceable calibration certificates.<\/p>","protected":false},"excerpt":{"rendered":"<p>Introduction to the Knoop Hardness Test The Knoop hardness test\u200b is a micro-indentation hardness testing method primarily used to measure<\/p>","protected":false},"author":4,"featured_media":30187,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[117],"tags":[135],"class_list":["post-30602","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hardness-tester","tag-knoop-hardness-test"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v25.4 (Yoast SEO v27.4) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Knoop Hardness Test: A Comprehensive Technical Guide - hardnesstests<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/hardnesstests.com\/es\/knoop-hardness-test-a-comprehensive-technical-guide\/\" \/>\n<meta property=\"og:locale\" content=\"es_ES\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Knoop Hardness Test: A Comprehensive Technical Guide\" \/>\n<meta property=\"og:description\" content=\"Introduction to the Knoop Hardness Test The Knoop hardness test\u200b is a micro-indentation hardness testing method primarily used to measure\" \/>\n<meta property=\"og:url\" content=\"https:\/\/hardnesstests.com\/es\/knoop-hardness-test-a-comprehensive-technical-guide\/\" \/>\n<meta property=\"og:site_name\" content=\"hardnesstests\" \/>\n<meta property=\"article:published_time\" content=\"2026-03-30T03:33:15+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-03-30T03:33:16+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"571\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"tingting\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Escrito por\" \/>\n\t<meta name=\"twitter:data1\" content=\"tingting\" \/>\n\t<meta name=\"twitter:label2\" content=\"Tiempo de lectura\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutos\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/\"},\"author\":{\"name\":\"tingting\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#\\\/schema\\\/person\\\/4dfcde616788fc5d9ece9551a87be8ce\"},\"headline\":\"Knoop Hardness Test: A Comprehensive Technical Guide\",\"datePublished\":\"2026-03-30T03:33:15+00:00\",\"dateModified\":\"2026-03-30T03:33:16+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/\"},\"wordCount\":1039,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2025\\\/12\\\/1.png\",\"keywords\":[\"knoop hardness test\"],\"articleSection\":[\"Hardness Tester\"],\"inLanguage\":\"es\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/\",\"url\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/\",\"name\":\"Knoop Hardness Test: A Comprehensive Technical Guide - hardnesstests\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2025\\\/12\\\/1.png\",\"datePublished\":\"2026-03-30T03:33:15+00:00\",\"dateModified\":\"2026-03-30T03:33:16+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#breadcrumb\"},\"inLanguage\":\"es\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#primaryimage\",\"url\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2025\\\/12\\\/1.png\",\"contentUrl\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2025\\\/12\\\/1.png\",\"width\":1200,\"height\":571},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/knoop-hardness-test-a-comprehensive-technical-guide\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\\\/\\\/hardnesstests.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Knoop Hardness Test: A Comprehensive Technical Guide\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#website\",\"url\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/\",\"name\":\"hardnesstests\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"es\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#organization\",\"name\":\"hardnesstests\",\"url\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2021\\\/08\\\/\u5fae\u4fe1\u56fe\u7247_20251029102004_335_1287.png\",\"contentUrl\":\"https:\\\/\\\/hardnesstests.com\\\/wp-content\\\/uploads\\\/2021\\\/08\\\/\u5fae\u4fe1\u56fe\u7247_20251029102004_335_1287.png\",\"width\":1308,\"height\":467,\"caption\":\"hardnesstests\"},\"image\":{\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#\\\/schema\\\/logo\\\/image\\\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/hardnesstests.com\\\/tr\\\/#\\\/schema\\\/person\\\/4dfcde616788fc5d9ece9551a87be8ce\",\"name\":\"tingting\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g\",\"caption\":\"tingting\"},\"url\":\"https:\\\/\\\/hardnesstests.com\\\/es\\\/author\\\/tingting\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Knoop Hardness Test: A Comprehensive Technical Guide - hardnesstests","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/hardnesstests.com\/es\/knoop-hardness-test-a-comprehensive-technical-guide\/","og_locale":"es_ES","og_type":"article","og_title":"Knoop Hardness Test: A Comprehensive Technical Guide","og_description":"Introduction to the Knoop Hardness Test The Knoop hardness test\u200b is a micro-indentation hardness testing method primarily used to measure","og_url":"https:\/\/hardnesstests.com\/es\/knoop-hardness-test-a-comprehensive-technical-guide\/","og_site_name":"hardnesstests","article_published_time":"2026-03-30T03:33:15+00:00","article_modified_time":"2026-03-30T03:33:16+00:00","og_image":[{"width":1200,"height":571,"url":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png","type":"image\/png"}],"author":"tingting","twitter_card":"summary_large_image","twitter_misc":{"Escrito por":"tingting","Tiempo de lectura":"7 minutos"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#article","isPartOf":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/"},"author":{"name":"tingting","@id":"https:\/\/hardnesstests.com\/tr\/#\/schema\/person\/4dfcde616788fc5d9ece9551a87be8ce"},"headline":"Knoop Hardness Test: A Comprehensive Technical Guide","datePublished":"2026-03-30T03:33:15+00:00","dateModified":"2026-03-30T03:33:16+00:00","mainEntityOfPage":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/"},"wordCount":1039,"commentCount":0,"publisher":{"@id":"https:\/\/hardnesstests.com\/tr\/#organization"},"image":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png","keywords":["knoop hardness test"],"articleSection":["Hardness Tester"],"inLanguage":"es","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/","url":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/","name":"Knoop Hardness Test: A Comprehensive Technical Guide - hardnesstests","isPartOf":{"@id":"https:\/\/hardnesstests.com\/tr\/#website"},"primaryImageOfPage":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#primaryimage"},"image":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png","datePublished":"2026-03-30T03:33:15+00:00","dateModified":"2026-03-30T03:33:16+00:00","breadcrumb":{"@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#breadcrumb"},"inLanguage":"es","potentialAction":[{"@type":"ReadAction","target":["https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/"]}]},{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#primaryimage","url":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png","contentUrl":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2025\/12\/1.png","width":1200,"height":571},{"@type":"BreadcrumbList","@id":"https:\/\/hardnesstests.com\/knoop-hardness-test-a-comprehensive-technical-guide\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/hardnesstests.com\/"},{"@type":"ListItem","position":2,"name":"Knoop Hardness Test: A Comprehensive Technical Guide"}]},{"@type":"WebSite","@id":"https:\/\/hardnesstests.com\/tr\/#website","url":"https:\/\/hardnesstests.com\/tr\/","name":"hardnesstests","description":"","publisher":{"@id":"https:\/\/hardnesstests.com\/tr\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/hardnesstests.com\/tr\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"es"},{"@type":"Organization","@id":"https:\/\/hardnesstests.com\/tr\/#organization","name":"hardnesstests","url":"https:\/\/hardnesstests.com\/tr\/","logo":{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/hardnesstests.com\/tr\/#\/schema\/logo\/image\/","url":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2021\/08\/\u5fae\u4fe1\u56fe\u7247_20251029102004_335_1287.png","contentUrl":"https:\/\/hardnesstests.com\/wp-content\/uploads\/2021\/08\/\u5fae\u4fe1\u56fe\u7247_20251029102004_335_1287.png","width":1308,"height":467,"caption":"hardnesstests"},"image":{"@id":"https:\/\/hardnesstests.com\/tr\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/hardnesstests.com\/tr\/#\/schema\/person\/4dfcde616788fc5d9ece9551a87be8ce","name":"tingting","image":{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/secure.gravatar.com\/avatar\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/860054326773b5d7efd55599c34646197790b492767738ff1ddf0e0ba0e05c7d?s=96&d=mm&r=g","caption":"tingting"},"url":"https:\/\/hardnesstests.com\/es\/author\/tingting\/"}]}},"_links":{"self":[{"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/posts\/30602","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/comments?post=30602"}],"version-history":[{"count":1,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/posts\/30602\/revisions"}],"predecessor-version":[{"id":30603,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/posts\/30602\/revisions\/30603"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/media\/30187"}],"wp:attachment":[{"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/media?parent=30602"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/categories?post=30602"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hardnesstests.com\/es\/wp-json\/wp\/v2\/tags?post=30602"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}