{"id":3240,"date":"2026-08-09T13:16:48","date_gmt":"2026-08-09T05:16:48","guid":{"rendered":"https:\/\/jtlcnc.com\/?p=3240"},"modified":"2026-08-09T13:16:49","modified_gmt":"2026-08-09T05:16:49","slug":"how-to-choose-suitable-marble-gauges-for-precision-inspection","status":"publish","type":"post","link":"https:\/\/jtlcnc.com\/ru\/2026\/08\/09\/how-to-choose-suitable-marble-gauges-for-precision-inspection\/","title":{"rendered":"How to choose suitable marble gauges for precision inspection"},"content":{"rendered":"

Complete Purchasing Guide for Precision Granite Measuring Tools (Industry Alias: Marble Measuring Tools)
The industry term “marble measuring tools” actually refers entirely to natural gabbro granite; cast iron and ordinary marble cannot meet the requirements of micron-level precision inspection. Selection is divided into 7 core dimensions: matching material, precision, size, thickness, process, certification, and accessories according to the application scenario, to avoid the pitfalls of low-priced, inferior stone materials.
I. Step One: Select the Precision Grade Based on Inspection Accuracy (National Standard GB\/T20428, equivalent to ISO8512)
The precision grade determines the flatness tolerance, directly matching your workshop\/laboratory environment. It is better to choose one grade higher than needed than to settle for a lower grade.
\u0422\u0430\u0431\u043b\u0438\u0446\u0430
Precision Grade Flatness Tolerance per Meter Standard Application Scenarios Environmental Requirements
Grade 000 (Highest) \u22641\u03bcm\/m Metrology institute standard bases, CMM machine bases, optical interferometers, semiconductor nano-inspection Constant temperature 20\u00b11\u2103, low-vibration metrology room, must be accompanied by a verification certificate
Grade 00 (Mainstream High Precision) \u22642\u03bcm\/m Precision mold quality inspection, gear inspection machines, imaging machine bases, aerospace component inspection Constant temperature 20\u00b12\u2103, no severe vibration in the workshop, standard for foreign trade equipment
Grade 0 (General Precision) \u22644\u03bcm\/m Machining production line spot checks, assembly bases, automated vision positioning Ordinary machining workshops, allows day-night temperature difference of \u00b13\u2103
Grade 1 (Rough Inspection) \u22648\u03bcm\/m Layout, tooling assembly, rough inspection of blanks Not recommended for precision dimension measurement
Selection Principles
CMM and optical equipment bases must be Grade 00\/000;
Constant temperature laboratories prioritize Grade 000, while ordinary precision quality inspection finds Grade 00 the most cost-effective;
In non-constant temperature workshops, cast iron is strictly forbidden as a substitute; at minimum, use Grade 00 granite to offset temperature errors.
II. Step Two: Core Material Selection (Determines long-term precision stability, the top priority)
Only high-density gabbro can be used for precision measuring tools. The performance of the 4 mainstream stone materials on the market is clearly distinguished:<\/p>\n\n\n\n

    \n
  1. Jinan Green (Top choice for the domestic precision industry)
    Physical parameters: Density 3.07g\/cm\u00b3, Shore hardness HS78~80, linear expansion coefficient 4.16\u00d710\u207b\u2076\/\u2103, water absorption rate <0.13%
    Advantages: Uniform crystallization, fully released internal stress, minimum thermal deformation, high vibration damping; standard for Zeiss, Mitutoyo, and domestic CMM original equipment
    Disadvantages: Limited mining, decreasing raw block inventory, relatively high price
    Applications: Grade 00\/000 high-precision platforms, straightedges, square rulers, CMM bases<\/li>\n\n\n\n
  2. Indian Black (Imported high-end material)
    Characteristics: Pure black throughout without impurities, finer grains, stronger corrosion and moisture resistance
    Performance is close to Jinan Green, but the price is 30%~80% higher, mostly used for high-end exported equipment accessories
    Applications: Overseas precision laboratories, high-humidity corrosive workshops, high-end metrology standard parts<\/li>\n\n\n\n
  3. Zhangqiu Green \/ Fujian G654 (Economical type)
    Hardness and thermal stability are average, prone to color differences, can only stably achieve Grade 0 precision
    Applications: Routine inspection in ordinary workshops, not recommended for micron-level precision measurement<\/li>\n\n\n\n
  4. Northeast Small Flower (Low-end material, avoid)
    Low density, many pores, large temperature variation, easily deformed over the long term, only used for Grade 1 rough inspection, directly excluded from precision inspection
    Material Selection Red Lines
    Reject dyed black stone materials, materials with many layers, or those covered with pores and white spots; materials with a density below 2.8g\/cm\u00b3 are unsuitable for precision inspection.<\/li>\n<\/ol>\n\n\n\n

    III. Step 3: Selection of Size, Thickness, and Load Capacity (To Prevent Self-Weight Deformation)<\/p>\n\n\n\n

      \n
    1. Tabletop Size Rules
      Maximum outer dimensions of the workpiece reserved clamping space on both sides \u2265 200mm, to avoid measurement tilting caused by the workpiece being suspended.
      Example: Workpiece length 800mm \u2192 Minimum platform selection 1000\u00d7800mm.<\/li>\n\n\n\n
    2. Thickness Standards (To Prevent Self-Weight Bending and Permanent Accuracy Drift)
      \u0422\u0430\u0431\u043b\u0438\u0446\u0430
      Platform Specification | Recommended Thickness | Uniform Load Capacity
      \u2264400\u00d7400mm | 100~150mm | \u22642 tons
      600\u00d7800 \/ 1000\u00d71000mm | 200~300mm | 3~5 tons
      \u22651500mm Large Platform | \u2265350mm | Heavy-duty inspection over 5 tons<\/li>\n\n\n\n
    3. Mandatory Support Requirements
      High-precision 00\/000 grade must be paired with three-point adjustable granite supports; direct floor placement or single-side support is prohibited; single-point loading will cause permanent micro-deformation.
      IV. Step 4: Distinguish Measuring Instrument Categories and Select According to Needs (Platform \/ Straightedge \/ Square \/ Square Ruler)
      Granite Full Set of Measuring Instruments
      Granite Straightedge
      Square
      Granite Inspection Platform (Most Commonly Used)
      Planar datum, height gauge, dial indicator, workpiece placement inspection; T-slots, threaded inserts, and cooling channels can be customized to adapt to CMM bases.
      Granite Straightedge (Straightness Inspection)
      Length 100~3000mm, 00 grade used for guide rail and machine tool bed straightness calibration; length > 1 meter must be thickened to prevent bending.
      Granite Square Box \/ Square
      Four-sided vertical datum, verticality tolerance within 0.002mm, tooling alignment, 90\u00b0 angle inspection.
      Granite Square Ruler (Triangle Square)
      Inspect workpiece verticality and mold side angles, small specification 100\u00d7160mm, large specification 800\u00d7500mm.
      V. Step 5: Processing Technology and Surface Quality Screening
      Working surface mirror-polished, roughness Ra0.8~1.6\u03bcm, no scratches, sand holes, chipped edges, or impact pits; slight scratches will directly cause micron-level measurement errors.
      Full-time Aging Treatment of Stone: Natural aging of raw blocks secondary manual stress relief of finished products; unaged stone will continuously creep and warp over 1~3 years of use.
      Chamfering Requirements: R3~R5 arc chamfering around the working surface to prevent chipping during handling.
      No Spliced Stone: Precision measuring instruments must be made of a single solid block of granite; splicing gaps will destroy the continuity of the datum.
      VI. Step 6: Certificates and Accuracy Traceability (Essential for Foreign Trade \/ Metrological Acceptance)
      Standard Factory Configuration: JJG117 granite surface plate verification certificate issued by a provincial metrology institute, accompanied by original laser interferometer inspection data, with traceable accuracy.
      Additional Requirements for Foreign Trade Export: Provide material property reports (thermal expansion coefficient, density, hardness test reports) to meet overseas customer laboratory audits.
      Pitfall Avoidance: Do not purchase products that only verbally claim 00 grade without any inspection certificates; accuracy is severely overstated.
      VII. Step 7: Selection Matching Working Conditions (Temperature, Vibration, Corrosion)
      Constant Temperature Metrology Room (20\u00b11\u2103)
      Optimal: Jinan Blue 000 grade, paired with vibration-damping supports, suitable for CMM and optical inspection.
      Ordinary Machining Workshop (Temperature difference \u00b13~5\u2103, air compressor vibration)
      Select Jinan Blue 00 grade, high-damping vibration reduction offsets vibration, low thermal expansion reduces temperature difference errors; cast iron platforms in this environment drift in accuracy by over 10\u03bcm annually.
      Humid \/ Cutting Fluid Corrosive Workshop
      Prioritize Indian Black, acid and alkali resistant, non-absorbent, rust-proof, no iron chip adsorption to interfere with measurement.
      High-Vibration Stamping \/ Forging Workshop<\/li>\n<\/ol>\n\n\n\n

      IX. Quick Selection Summary (Minimalist Procurement Mnemonic)
      For CMM, 000 grade is the Jinan Qing; for precision inspection tables, 00 grade is the top choice;
      If the workshop temperature varies greatly, never choose cast iron; when calculating dimensions, do not skimp on thickness;
      For solid monolithic blocks, add lead time and certificates; with three-point supports, accuracy remains stable for ten years.<\/p>\n\n\n\n

      \"\"<\/figure>","protected":false},"excerpt":{"rendered":"

      Complete Purchasing Guide for Precision Granite Measuring Tools (Industry Alias: Marble Measuring Tools)The industry term “marble measuring tools” actually refers entirely to natural gabbro granite; cast iron and ordinary marble cannot meet the requirements of micron-level precision inspection. Selection is divided into 7 core dimensions: matching material, precision, size, thickness, process, certification, and accessories according…<\/p>","protected":false},"author":1,"featured_media":3241,"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-3240","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\/14-1024x725.png",1024,725,true],"author_info":{"display_name":"jinxing6611@gmail.com","author_link":"https:\/\/jtlcnc.com\/ru\/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":362,"filter":"raw","cat_ID":35,"category_count":362,"category_description":"","cat_name":"NEWS","category_nicename":"news","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/posts\/3240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/comments?post=3240"}],"version-history":[{"count":1,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/posts\/3240\/revisions"}],"predecessor-version":[{"id":3242,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/posts\/3240\/revisions\/3242"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/media\/3241"}],"wp:attachment":[{"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/media?parent=3240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/categories?post=3240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jtlcnc.com\/ru\/wp-json\/wp\/v2\/tags?post=3240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}