{"id":3253,"date":"2026-08-13T09:03:54","date_gmt":"2026-08-13T01:03:54","guid":{"rendered":"https:\/\/jtlcnc.com\/?p=3253"},"modified":"2026-08-13T09:03:55","modified_gmt":"2026-08-13T01:03:55","slug":"what-is-the-machining-process-for-a-high-precision-grade-00-000-granite-platform","status":"publish","type":"post","link":"https:\/\/jtlcnc.com\/es\/2026\/08\/13\/what-is-the-machining-process-for-a-high-precision-grade-00-000-granite-platform\/","title":{"rendered":"What is the machining process for a high-precision grade 00\/000 granite platform?"},"content":{"rendered":"<h1 class=\"wp-block-heading\">Complete Processing Workflow for # 00\/000 Grade High-Precision Granite Plate<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Adhering to the national standard <strong>GB\/T 20428 &#8220;Granite Flat Plates&#8221;<\/strong>, the entire precision machining process must be completed in a <strong>dust-free, vibration-dampened workshop at a constant temperature of 20\u00b10.5\u2103<\/strong>. The core process is divided into nine major stages: <strong>Raw Material Screening \u2192 Rough Cutting \u2192 Rough Machining \u2192 Multi-stage Stress Relief Aging \u2192 Gradient Mechanical Grinding \u2192 Manual Super-precision Matching and Grinding \u2192 Functional Hole and Slot Machining \u2192 Final Inspection and Calibration \u2192 Finished Product Stabilization Aging<\/strong>. Among these, <strong>manual matching and grinding, and multi-stage stress release<\/strong> are the core critical processes that distinguish ordinary Grade 0 from Grade 00\/000.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">I. Strict Raw Material Screening (The Foundation for Long-term Deformation Resistance)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Only <strong>Jinan Qinghui Longyan \/ Indian Black Fine-grained Granite<\/strong> is selected. All materials undergo full inspection to eliminate inclusions, sand holes, hidden cracks, and mica soft bands:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Hard Thresholds for Physical Indicators<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Compressive strength \u2265245MPa, Shore hardness HS72~80, density \u22652.97g\/cm\u00b3<\/li>\n\n\n\n<li>Water absorption \u22640.13%, linear expansion coefficient \u22644.5\u00d710\u207b\u2076\/\u2103, non-magnetic<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Non-destructive Testing: Ultrasonic flaw detection to screen for internal hidden cracks; petrographic analysis to ensure uniform grains without stratification<\/li>\n\n\n\n<li>Natural Pre-aging of Rough Blocks: Rough blocks from the mine are left to rest outdoors for 3 to 6 months to release geological native stresses; unqualified rough blocks are scrapped directly<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">II. Rough Cutting and Blank Shaping<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Diamond large saws cut the material according to drawing dimensions, leaving a <strong>machining allowance of 8~12mm<\/strong> on each side for length, width, and thickness. Deep cutting in a single pass to cause micro-cracks at the edges and corners is strictly prohibited<\/li>\n\n\n\n<li>Gantry CNC grinders rough-mill the six faces to remove saw marks and correct overall warping; after rough machining, the flatness is controlled within 0.05mm\/m<\/li>\n\n\n\n<li>Rough chamfering of R2 on all four sides to prevent edge chipping during transport<\/li>\n\n\n\n<li><strong>First Aging Stage<\/strong> after rough machining: Manual composite stress relief (24h insulation in an 80\u2103 drying room \u2192 4h deep freezing at -10\u2103 \u2192 72h resting at a constant 20\u2103) to eliminate mechanical stresses generated by sawing and milling, avoiding later creep and warping<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">III. Semi-precision Grinding Process (Gradient Grinding and Polishing to Gradually Compress Flatness Error)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">All operations are executed in a constant temperature workshop, with the grinding wheel grit progressing from coarse to fine:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>200#~400# diamond wheel semi-precision grinding: Eliminates rough milling tool marks, compressing flatness to 5~10\u03bcm\/m<\/li>\n\n\n\n<li>800#~1200# fine grinding: Refines surface texture, achieving flatness \u22643\u03bcm\/m and surface roughness Ra \u22641.6\u03bcm<\/li>\n\n\n\n<li>After each round of grinding, the plate is flipped and rested for 24h to release grinding stress; Grade 000 plates require two alternating rounds of semi-precision grinding on both sides<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">IV. Core Process 1: Secondary Long-term Constant Temperature Natural Aging (Mandatory for Grade 00\/000)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">After rough grinding, the plate must enter a constant temperature room to rest, which is the key to ensuring precision does not drift for several years:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Grade 00 plates: Laid flat at a constant temperature of 20\u00b11\u2103 and 45% RH for <strong>2 weeks<\/strong>, flipped every 7 days to allow uniform stress release<\/li>\n\n\n\n<li>Grade 000 metrology reference plates: Constant temperature resting for <strong>over 4 weeks<\/strong>; for large plates over 1500mm, this is extended to 3 months<\/li>\n\n\n\n<li>Principle: Grinding generates residual stress on the surface layer; insufficient aging will cause the finished product to slowly bend and exceed flatness standards after 1 to 3 years of use<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">V. Core Process 2: Manual Pairing and Ultra-Precision Grinding (Exclusive to Grade 00\/000, determining micron-level accuracy)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Due to the inherent error limits of machine tool guide rails, mechanical grinders cannot achieve an ultra-high flatness of 1~2\u03bcm\/m. Manual pairing and grinding correction are mandatory:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Grade 00 Platform Grinding Solution<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Abrasive: W7 and W10 silicon carbide micro-powder; standard cast iron reference plates are mutually ground.<\/li>\n\n\n\n<li>Grid multi-point cyclic grinding: Grid measurement points are checked every 30 minutes using a high-precision electronic level, and high points are manually scraped.<\/li>\n\n\n\n<li>All six sides are flipped and cycled for mutual grinding 3 times to ensure the parallelism and perpendicularity of the working surface, bottom surface, and four side surfaces meet standards, achieving a final flatness of \u22642\u03bcm\/m.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. Grade 000 Metrological Reference Grinding Solution (Highest Precision)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ultra-fine W3.5 diamond micro-powder wet grinding: Grinding time per side \u22654h, alternating mutual grinding of front and back surfaces to eliminate unidirectional stress.<\/li>\n\n\n\n<li>Laser reference flat block alignment: Contact spots are observed using the spot method, ensuring uniform distribution of spots across the entire plate surface without local high points.<\/li>\n\n\n\n<li>Final flatness tolerance \u22641\u03bcm\/m, working surface roughness Ra \u22640.1\u03bcm, mirror-like finish without any scratches or pitting.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">VI. Functional Feature Precision Machining (Drilling, T-slots, Thread Embedding)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Hole and slot machining is performed after precision grinding to prevent slotting from damaging the high-precision reference surface:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>5-axis CNC drilling and milling center processes threaded holes and T-slots, leaving a 0.5mm precision grinding allowance on one side, followed by local polishing and deburring.<\/li>\n\n\n\n<li>Stainless steel wire thread inserts are embedded in threaded holes, reinforced with epoxy glue cured for 24h to prevent local collapse from clamping tools.<\/li>\n\n\n\n<li>Slot walls and hole edges are finely chamfered with R3~R5 arcs to eliminate stress concentration and edge chipping.<\/li>\n\n\n\n<li>Local vibration aging for 30 minutes after machining to eliminate local stresses caused by drilling and slotting.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">VII. Ultimate All-Dimensional Precision Inspection (Laser Interferometry Traceable Verification)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Inspection environment maintained at a constant temperature of 20\u00b10.5\u2103, using a laser plane interferometer, a 0.001mm\/m high-precision electronic level, and a CMM for dimensional measurement:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Flatness: Data is collected from diagonals and grid multi-points; software fits and calculates the flatness error, strictly corresponding to the GB 00\/000 grade tolerances.<\/li>\n\n\n\n<li>Full inspection of hexahedron parallelism, adjacent surface perpendicularity, and thickness uniformity.<\/li>\n\n\n\n<li>Full inspection of surface roughness and appearance: No sand holes, scratches, dents, or discolored inclusions.<\/li>\n\n\n\n<li>Load deflection spot check: Centrally load the rated weight, ensuring a flatness recovery rate of \u226599.98% after unloading to confirm no permanent deformation.<\/li>\n\n\n\n<li>Inspection data is archived, and a traceable verification certificate (JJG117) from the Metrology Institute is issued.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">VIII. Final Stability Aging of Finished Products (Closed-loop Process Before Factory Release)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">After passing inspection, an additional vibration aging constant temperature static aging step is added:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>30~60Hz vibration aging for 60~90min to release all residual machining stresses.<\/li>\n\n\n\n<li>Constant temperature room static aging for 72h, followed by a second flatness re-test; if minor drift occurs, it must be reworked and re-ground.<\/li>\n\n\n\n<li>Only after passing the re-test can it proceed to cleaning, wax sealing protection, and packaging for factory release.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">IX. Comparison of Key Process Differences Between Grade 00 and Grade 000<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Cuadro<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Process Step<\/th><th>Grade 00 Precision Platform (General Mold \/ CMM)<\/th><th>Grade 000 Reference Platform (Metrology Institute \/ Semiconductor)<\/th><\/tr><\/thead><tbody><tr><td>Constant temperature natural aging duration<\/td><td>14 days<\/td><td>28~90 days<\/td><\/tr><tr><td>Manual grinding abrasive particle size<\/td><td>W7\/W10<\/td><td>W3.5 ultra-fine diamond powder<\/td><\/tr><tr><td>Single-side hole grinding duration<\/td><td>\u22652h<\/td><td>\u22654h<\/td><\/tr><tr><td>Flatness tolerance<\/td><td>\u22642\u03bcm\/m<\/td><td>\u22641\u03bcm\/m<\/td><\/tr><tr><td>Rugosidad de la superficie<\/td><td>Ra0.2~0.6\u03bcm<\/td><td>Ra\u22640.1\u03bcm mirror finish<\/td><\/tr><tr><td>Factory re-inspection frequency<\/td><td>1 final inspection<\/td><td>Two laser re-tests: after grinding after aging<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img alt=\"\" fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"550\" src=\"https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-1024x550.png\" class=\"wp-image-3254\" srcset=\"https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-1024x550.png 1024w, https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-300x161.png 300w, https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-768x413.png 768w, https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-18x10.png 18w, https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-800x430.png 800w, https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu.png 1150w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>","protected":false},"excerpt":{"rendered":"<p>Complete Processing Workflow for # 00\/000 Grade High-Precision Granite Plate Adhering to the national standard GB\/T 20428 &#8220;Granite Flat Plates&#8221;, the entire precision machining process must be completed in a dust-free, vibration-dampened workshop at a constant temperature of 20\u00b10.5\u2103. The core process is divided into nine major stages: Raw Material Screening \u2192 Rough Cutting \u2192&#8230;<\/p>","protected":false},"author":1,"featured_media":3254,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"","_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[35],"tags":[],"class_list":["post-3253","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"taxonomy_info":{"category":[{"value":35,"label":"NEWS"}]},"featured_image_src_large":["https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/08\/uu-1024x550.png",1024,550,true],"author_info":{"display_name":"jinxing6611@gmail.com","author_link":"https:\/\/jtlcnc.com\/es\/author\/jtlcnc\/"},"comment_info":0,"category_info":[{"term_id":35,"name":"NEWS","slug":"news","term_group":0,"term_taxonomy_id":35,"taxonomy":"category","description":"","parent":0,"count":334,"filter":"raw","cat_ID":35,"category_count":334,"category_description":"","cat_name":"NEWS","category_nicename":"news","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/posts\/3253","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/comments?post=3253"}],"version-history":[{"count":1,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/posts\/3253\/revisions"}],"predecessor-version":[{"id":3255,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/posts\/3253\/revisions\/3255"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/media\/3254"}],"wp:attachment":[{"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/media?parent=3253"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/categories?post=3253"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jtlcnc.com\/es\/wp-json\/wp\/v2\/tags?post=3253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}