[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-571322-105":3,"detail-sidebar-cat-1-en-105":81,"doc-detail-571322-en":127},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","viscosity-classifications-iso","Viscosity Classifications - ISO","","Viscosity Classifications explains how lubricant viscosity is standardized to guide oil and grease selection. It details ISO viscosity classification for industrial lubricating oils using mm2/s (cSt) at 40°C, including 18 viscosity brackets and how grade numbers map to bracket mid-points and limits. It also covers grease consistency via NLGI penetration ranges, AGMA lubricant specifications for gear oils with corresponding ISO grades, and engine oil viscosity classification principles under SAE J300, including W-grade low-temperature behavior and multi-grade requirements.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/template/","Template",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/template/general/","General",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/template/viscosity-classifications-iso/571322/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/viscosity-classifications-iso/571322.png","ImageObject",442,249,{"name":42,"@type":43},"mieayamfan","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-22","2026-10-13",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",7,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"How does the ISO viscosity classification define viscosity grades for industrial lubricants?","Question",{"text":63,"@type":64},"ISO uses mm2/s (cSt) viscosity measured at 40°C and divides the range into 18 viscosity brackets from 1.98 to 1650 mm2/s. Each bracket is associated with a viscosity grade number whose value corresponds to the bracket midpoint.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"What does NLGI grease consistency classification measure?",{"text":68,"@type":64},"NLGI classifies greases by hardness or softness only, using the distance (in tenths of a millimetre) that a standard cone penetrates the grease under standard conditions at 25°C.",{"name":70,"@type":61,"acceptedAnswer":71},"What distinguishes SAE J300 W-grades from non-W grades for engine oils?",{"text":72,"@type":64},"W-grades are intended for lower temperatures and are based on maximum low-temperature viscosity and a maximum borderline pumping temperature, plus a minimum viscosity at 100°C. Non-W grades are intended for higher temperatures and are based on viscosity at 100°C only.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},571322,1792100614,{"code":4,"msg":82,"data":83},"success",[84,89,94,99,104,109,114,119,124],{"id":85,"doc_module":22,"doc_module_name":25,"category_name":86,"show_sort_weight":87,"slug":88},11,"Presentations",90,"presentations",{"id":90,"doc_module":22,"doc_module_name":25,"category_name":91,"show_sort_weight":92,"slug":93},12,"Resumes",80,"resumes",{"id":95,"doc_module":22,"doc_module_name":25,"category_name":96,"show_sort_weight":97,"slug":98},14,"Invoices",70,"invoices",{"id":100,"doc_module":22,"doc_module_name":25,"category_name":101,"show_sort_weight":102,"slug":103},15,"Posters",60,"posters",{"id":105,"doc_module":22,"doc_module_name":25,"category_name":106,"show_sort_weight":107,"slug":108},16,"Social Media",50,"social-media",{"id":110,"doc_module":22,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},17,"Forms",40,"forms",{"id":115,"doc_module":22,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},18,"Letters",30,"letters",{"id":120,"doc_module":22,"doc_module_name":25,"category_name":121,"show_sort_weight":122,"slug":123},21,"Paper Templates",5,"papers-templates",{"id":125,"doc_module":22,"doc_module_name":25,"category_name":29,"show_sort_weight":4,"slug":126},158,"general-158",{"code":4,"msg":82,"data":128},{"doc_id":79,"user_id":129,"nickname":42,"user_avatar":130,"doc_module":22,"category_id":125,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":131,"file_id":132,"file_url":133,"file_type":134,"file_size":135,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":136,"language":137,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":138,"faqs":139,"seo_title":140,"seo_description":12,"update_tm":141,"read_time":30},962090893677,"https://ap-avatar.wpscdn.com/davatar_3d24733baf745e90a7e4bdd5f77d97b2","VISCOSITY CLASSIFICATIONS  \nINDUSTRIAL LUBRICANT CASSIFICATIONS  \nISO (International Standards Organisation) viscosity classification  \nThe ISO viscosity classification uses mm2/s (cSt) units and relates to viscosity at 40oC. It consists of a series of 18 viscosity brackets between 1.98 mm2/s and 1650 mm2/s, each of which is defined by a number. The numbers indicate to the nearest whole number, the mid points of their corresponding brackets. For example, ISO viscosity grade 32 relates to the viscosity bracket 28.8 to 35.2 mm2/s, the mid point of which is 32.0 mm2/s. This is illustrated in the table below, which shows the ISO viscosity grade numbers, the mid-points of each bracket, and the viscosity limits. This system is now used to classify all industrial lubricating oils where viscosity is an important criterion in the selection of the oil. Cutting oil and some other specialized products are more important in relation to grade selection.  \n\n| ISO VISCOSITY GRADE (ISO VG) | KINEMATIC VISCOSITY AT 40oC (mm2/s) |  |  |\n| --- | --- | --- | --- |\n|  | Minimum | Maximum | Mid-point |\n| 2 | 1.98 | 2.42 | 2.20 |\n| 3 | 2.88 | 3.52 | 3.20 |\n| 5 | 4.14 | 5.06 | 4.60 |\n| 7 | 6.12 | 7.48 | 6.80 |\n| 10 | 9.0 | 11.0 | 10.0 |\n| 15 | 13.5 | 16.5 | 15.0 |\n| 22 | 19.8 | 24.2 | 22.0 |\n| 32 | 28.8 | 35.2 | 32.0 |\n| 46 | 41.4 | 50.6 | 46.0 |\n| 68 | 61.2 | 74.8 | 68.0 |\n| 100 | 90.0 | 110 | 100 |\n| 150 | 135 | 165 | 150 |\n| 220 | 198 | 242 | 220 |\n| 320 | 288 | 352 | 320 |\n| 460 | 414 | 506 | 460 |\n| 680 | 612 | 748 | 680 |\n| 1000 | 900 | 1100 | 1000 |\n| 1500 | 1350 | 1650 | 1500 |\n\nGREASE CLASSIFICATIONS  \nNLGI GREASE CONSISTENCY CLASSIFICATION  \nThe commonly used grease consistency classification is that established in the USA many years ago by the National Lubricating Grease Institute (NLG) . This classifies greases solely in terms of their hardness or softness; no other property or performance level is taken into consideration.  \nThe classification consists of a series of consistency range, each of which is defined by a number (or numbers) 000 to 6 . The consistency, defined by the distance in tenths of a millimetre, that a  \nstandard cone penetrates a sample of the grease number under standard conditions at 25oC. This system is used to classify industrial greases.  \nNLGI Grease Classification (National Lubricating Grease Institute)  \n\n| NLGI CONSISTENCY\u003Cbr>(Grade No.) | ASTM WORKED PENETRATION AT 25oC\u003Cbr>(0. 1mm) |\n| --- | --- |\n| 000 | 445 – 475 |\n| 00 | 400 – 430 |\n| 0 | 355 – 385 |\n| 1 | 310 – 340 |\n| 2 | 265 – 295 |\n| 3 | 220 – 250 |\n| 4 | 175-205 |\n| 5 | 130-160 |\n| 6 | 85 – 115 |\n\nAGMA Specifications for Gear Lubricants  \nThe American Gear Manufacturers Association (AGMA) have issued specifications and recommendations for gear lubricants used in various types of gear application. AGMA Standard 250 .04 details specifications for rust and oxidation inhibited (R and O) and extreme-pressure (EP) lubricants used in enclosed gear drives.  \nThe viscosity brackets correspond to those given in ASTM D 2422 ‘Standard Recommended Practice for Viscosity System for Industrial Fluid Lubricants’.  \nAGMA Viscosity Grades for Enclosed Gearing  \n\n| AGMA Lubricant No. | Viscosity Limits of former AGMA Classifications SUS at 100ºF | Corresponding ISO Viscosity Grade |\n| --- | --- | --- |\n| 1 | 193 – 235 | 46 |\n| 2, 2 EP | 284 – 347 | 68 |\n| 3, 3 EP | 417 – 510 | 100 |\n| 4, 4 EP | 626 – 765 | 150 |\n| 5, 5 EP | 918 – 1122 | 220 |\n| 6, 6 EP | 1335 – 1632 | 320 |\n| 7 Comp, 7EP | 1919 –2346 | 460 |\n| 8 Comp, 8EP | 2837 – 3467 | 680 |\n| 8A Comp | 4171 – 5098 | 1000 |\n\nOils marked ‘comp’ are compounded with 3 to 10% fatty material.  \nThe AGMA Standard 251 .02 details specifications for three types of open gear lubricants – rust and oxidation inhibited (R and O), extreme-pressure (EP) and residual type gear oils. In this case the viscosity brackets for the higher viscosity grades are measured at 100 C.  \nLUBRICANT VISCOSITY CLASSIFICATIONS  \nENGINE OIL LUBRICANT CL","cbCairUfA749z2uD","https://ap.wps.com/l/cbCairUfA749z2uD","pdf",90313,8,"English","# ISO viscosity classification\n## ISO VG viscosity brackets (mm2/s at 40°C)\n# Grease classifications\n## NLGI grease consistency (cone penetration at 25°C)\n## AGMA specifications for gear lubricants\n### AGMA viscosity grades for enclosed gearing\n### AGMA specifications for open gear lubricants\n# Lubricant viscosity classifications\n## Engine oil lubricant classifications\n### SAE J300 engine oil viscosity grades (W and non-W)","[{\"question\":\"How does the ISO viscosity classification define viscosity grades for industrial lubricants?\",\"answer\":\"ISO uses mm2/s (cSt) viscosity measured at 40°C and divides the range into 18 viscosity brackets from 1.98 to 1650 mm2/s. Each bracket is associated with a viscosity grade number whose value corresponds to the bracket midpoint.\"},{\"question\":\"What does NLGI grease consistency classification measure?\",\"answer\":\"NLGI classifies greases by hardness or softness only, using the distance (in tenths of a millimetre) that a standard cone penetrates the grease under standard conditions at 25°C.\"},{\"question\":\"What distinguishes SAE J300 W-grades from non-W grades for engine oils?\",\"answer\":\"W-grades are intended for lower temperatures and are based on maximum low-temperature viscosity and a maximum borderline pumping temperature, plus a minimum viscosity at 100°C. Non-W grades are intended for higher temperatures and are based on viscosity at 100°C only.\"}]","Viscosity Classifications - ISO | PDF",1791912583]