{"id":1482,"date":"2020-04-18T05:40:48","date_gmt":"2020-04-18T05:40:48","guid":{"rendered":"http:\/\/fastenerworld.ae\/?post_type=product&p=947"},"modified":"2026-07-06T10:25:22","modified_gmt":"2026-07-06T10:25:22","slug":"hex-jam-nuts","status":"publish","type":"product","link":"https:\/\/asiabolt.om\/ar\/product\/hex-jam-nuts\/","title":{"rendered":"Hex Jam Nuts"},"content":{"rendered":"

Hex Jam Nuts \u2013 Thin Hex Nut & Half Nut Manufacturer & Supplier in UAE<\/h4>\n

Asia Bolts Industries LLC is a trusted Hex Jam Nut manufacturer and supplier<\/strong> based in Dubai, UAE, delivering precision-engineered thin hex nut fastening solutions to the oil & gas, petrochemical, construction, mechanical engineering, and general industrial sectors across the GCC and global markets since 1997. Our Hex Jam Nuts provide a reliable, reusable, all-metal locking mechanism for bolted joints subjected to vibration, thermal cycling, and dynamic loading \u2014 suitable across the full temperature range where nylon insert nuts fail, and across the full size range where wedge locking nuts are cost-prohibitive.<\/p>\n

\n

What Are Hex Jam Nuts?<\/h4>\n

Hex Jam Nuts are hexagonal nuts manufactured to a reduced height \u2014 approximately half the height of a standard hex nut<\/strong> \u2014 giving rise to the common alternative names Half Nuts<\/strong> or Thin Hex Nuts<\/strong>. Their primary function is as a locking element in a double-nut assembly<\/strong>: the jam nut is threaded onto the bolt first, followed by the primary (full-height) hex nut, which is then tightened to the required clamping torque. The jam nut is then back-torqued against the primary nut \u2014 creating a compressive preload between the two nut faces that locks both nuts against rotation on the bolt thread.<\/p>\n

The double-nut locking principle operates through thread interface compression<\/strong> \u2014 the opposing torque applied to the jam nut and primary nut generates a tensile load in the bolt shank between the two nuts, which presses the thread flanks of both nuts firmly against the bolt thread in opposing directions. This mechanical interlock resists loosening under vibration without relying on friction coefficient consistency, temperature-sensitive materials, or consumable locking agents.<\/p>\n

Beyond their primary locking function, Hex Jam Nuts are also used as:<\/p>\n

    \n
  • Adjustment nuts<\/strong> \u2014 on threaded rod assemblies, machine slides, and linear actuators where precise positional adjustment and locking at the set position is required<\/li>\n
  • Spacer nuts<\/strong> \u2014 providing a defined standoff distance on a threaded rod between two structural elements<\/li>\n
  • Thread end protection<\/strong> \u2014 a low-profile nut run to the end of a threaded rod or bolt to protect the thread during handling, storage, and installation<\/li>\n
  • Bearing preload adjustment<\/strong> \u2014 in machine tool and precision spindle assemblies where bearing preload is set by jam nut adjustment against a locknut<\/li>\n
  • Turnbuckle locking<\/strong> \u2014 jam nuts at each end of a turnbuckle body lock the turnbuckle at its set adjustment position<\/li>\n<\/ul>\n

    They are widely used in:<\/p>\n

      \n
    • Oil & gas surface equipment<\/strong> \u2014 threaded rod adjustments, instrument support locking, skid frame connections<\/li>\n
    • Structural steelwork<\/strong> \u2014 double-nut locking on anchor bolts, tension rod assemblies, levelling bolt arrangements<\/li>\n
    • Machine tools and precision equipment<\/strong> \u2014 ball screw end bearing preload, slide adjustment locking, spindle nut locking<\/li>\n
    • Pipework and mechanical supports<\/strong> \u2014 hanger rod locking, pipe support height adjustment and locking<\/li>\n
    • Electrical and telecommunications towers<\/strong> \u2014 guy anchor rod locking, mast base connection double-nut assemblies<\/li>\n
    • Construction and civil engineering<\/strong> \u2014 anchor bolt double-nut locking, levelling nut assemblies under base plates<\/li>\n
    • Agricultural and heavy machinery<\/strong> \u2014 adjustment rod locking, implement connection double-nut assemblies<\/li>\n<\/ul>\n
      \n

      Types of Hex Jam Nuts Available<\/h4>\n

      1. Thin Hex Jam Nut \u2014 DIN 439<\/strong>
      \nThe standard metric jam nut configuration \u2014 a full hexagonal profile at reduced height (approximately 0.5\u00d7 standard nut height) without chamfer on the bearing face. The most widely stocked jam nut in the GCC market. Available in metric coarse thread M1.6 to M64 in carbon steel zinc plated and stainless steel AISI 304 \/ 316 as standard stock items at our Dubai facility.<\/p>\n

      2. Chamfered Thin Hex Nut \u2014 DIN 936<\/strong>
      \nA reduced-height hex nut with a chamfered bearing face \u2014 providing a cleaner thread run-on and improved contact with the mating surface compared to DIN 439. Specified where a more refined bearing face geometry is required, particularly in precision mechanical and instrument applications.<\/p>\n

      3. Heavy Hex Jam Nut \u2014 ASTM A194 \/ ASME B18.2.2<\/strong>
      \nA reduced-height jam nut with an increased hex width (heavy hex profile) \u2014 providing greater wrench engagement and higher proof load capacity than standard metric jam nuts. Widely specified for ASTM A193 B7 stud bolt assemblies<\/strong> in high-pressure process flanges, pressure vessel connections, and structural anchor bolt packages across oil & gas and petrochemical projects in the GCC.<\/p>\n

      4. Stainless Steel Hex Jam Nut<\/strong>
      \nFull DIN 439 \/ DIN 936 thin hex jam nuts in AISI 304, 304L, 316, and 316L stainless steel for corrosive environment applications \u2014 offshore topsides, marine equipment, chemical plant, food processing installations, and architectural steelwork in coastal GCC locations.<\/p>\n

      5. Fine Pitch Hex Jam Nut<\/strong>
      \nThin hex jam nuts with metric fine pitch thread (e.g. M20\u00d71.5, M24\u00d72.0) for precision mechanical applications \u2014 machine tool spindles, ball screw assemblies, and instrument mechanisms where fine thread pitch provides superior adjustment resolution and higher thread stripping resistance at reduced nut height.<\/p>\n

      6. Large Diameter Hex Jam Nut<\/strong>
      \nFor heavy structural and civil applications requiring jam nuts in M48, M56, M64, M72, M80, and M100 \u2014 manufactured to customer drawing in carbon steel, alloy steel, and stainless steel grades with full material traceability and dimensional inspection.<\/p>\n

      \n

      Standards & Specifications<\/h4>\n
      \n\n\n\n\n\n\n\n\n\n\n\n\n\n
      Standard<\/th>\nDescription<\/th>\n<\/tr>\n<\/thead>\n
      DIN 439<\/strong><\/td>\nHexagon thin nuts (jam nuts) \u2014 metric coarse, no chamfer<\/td>\n<\/tr>\n
      DIN 936<\/strong><\/td>\nHexagon thin nuts (jam nuts) \u2014 metric coarse, with chamfer<\/td>\n<\/tr>\n
      ISO 4035<\/strong><\/td>\nHexagon thin nuts \u2014 chamfered, Grade A & B<\/td>\n<\/tr>\n
      ISO 4036<\/strong><\/td>\nHexagon thin nuts \u2014 unchamfered<\/td>\n<\/tr>\n
      ASME B18.2.2<\/strong><\/td>\nHex nuts including jam nuts \u2014 inch series<\/td>\n<\/tr>\n
      ASTM A563<\/strong><\/td>\nCarbon and alloy steel nuts including jam nuts<\/td>\n<\/tr>\n
      ASTM A194 2H<\/strong><\/td>\nHeavy hex nuts for high-pressure bolting \u2014 jam nut variants<\/td>\n<\/tr>\n
      BS 3692<\/strong><\/td>\nISO metric precision hexagon bolts, screws and nuts<\/td>\n<\/tr>\n
      BS 4190<\/strong><\/td>\nISO metric black hexagon bolts, screws and nuts<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

      Fine pitch thread variants (ISO 8675), left-hand thread, and non-standard body height configurations available on request.<\/p>\n

      \n

      Materials & Grades Available<\/h4>\n
      \n\n\n\n\n\n\n\n\n\n\n\n\n
      Material<\/th>\nGrade \/ Specification<\/th>\nTypical Application<\/th>\n<\/tr>\n<\/thead>\n
      Carbon Steel<\/strong><\/td>\nProperty Class 04, 05 (zinc plated standard)<\/td>\nGeneral industrial, structural, construction<\/td>\n<\/tr>\n
      Alloy Steel<\/strong><\/td>\nASTM A194 2H, 4, 7, 7M<\/td>\nHigh-pressure stud bolt assemblies, O&G<\/td>\n<\/tr>\n
      Stainless Steel<\/strong><\/td>\nAISI 304, 304L, 316, 316L<\/td>\nCorrosive, marine, food-grade, architectural<\/td>\n<\/tr>\n
      Duplex Steel<\/strong><\/td>\nUNS S31803 (2205)<\/td>\nOffshore, sour service, coastal GCC<\/td>\n<\/tr>\n
      Super Duplex<\/strong><\/td>\nUNS S32750 (2507)<\/td>\nSubsea, highly aggressive offshore service<\/td>\n<\/tr>\n
      Brass<\/strong><\/td>\nCuZn39Pb3<\/td>\nElectrical, instrumentation, low-load assemblies<\/td>\n<\/tr>\n
      Inconel<\/strong><\/td>\nAlloy 718<\/td>\nHigh-temperature, extreme service<\/td>\n<\/tr>\n
      Titanium<\/strong><\/td>\nGrade 2 \/ Grade 5<\/td>\nLightweight, highly corrosive environments<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

      Surface treatment options include zinc electroplating, hot-dip galvanising (HDG), PTFE coating (Xylan), Geomet, Dacromet, black oxide, nickel plating<\/strong>, and passivation<\/strong> for stainless grades.<\/p>\n

      \n

      Dimensions & Size Range<\/h4>\n
      \n\n\n\n\n\n\n\n\n\n\n\n\n
      Parameter<\/th>\nRange<\/th>\n<\/tr>\n<\/thead>\n
      Thread Size<\/strong><\/td>\nM1.6 to M100 (metric) | No. 0 to 4″ (imperial)<\/td>\n<\/tr>\n
      Thread Pitch<\/strong><\/td>\nMetric coarse (standard) \/ fine pitch on request<\/td>\n<\/tr>\n
      Nut Height<\/strong><\/td>\n~0.5\u00d7 standard hex nut height per DIN 439 \/ DIN 936<\/td>\n<\/tr>\n
      Hex Profile<\/strong><\/td>\nStandard hex \/ Heavy hex (increased AF width)<\/td>\n<\/tr>\n
      Property Class<\/strong><\/td>\n04, 05 (metric jam) | Grade A, B, C (ASTM A563)<\/td>\n<\/tr>\n
      Finish<\/strong><\/td>\nZinc plated, HDG, plain, PTFE, Geomet, black oxide<\/td>\n<\/tr>\n
      Tolerance<\/strong><\/td>\nGrade A & B per ISO 4759-1<\/td>\n<\/tr>\n
      Thread Form<\/strong><\/td>\nMetric coarse \/ fine \/ UNC \/ UNF \/ BSF \/ left-hand<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
      \n

      How to Correctly Install a Double-Nut Jam Nut Assembly<\/h4>\n

      Correct installation sequence is critical to achieving the designed locking performance of a double-nut assembly:<\/p>\n

      Step 1<\/strong> \u2014 Thread the jam nut (thin hex)<\/strong> onto the bolt or stud first and run it down to the joint surface. Do not fully tighten at this stage.<\/p>\n

      Step 2<\/strong> \u2014 Thread the primary nut (full hex)<\/strong> onto the bolt above the jam nut and tighten to the specified installation torque for the bolt grade and size.<\/p>\n

      Step 3<\/strong> \u2014 Hold the primary nut<\/strong> stationary with one spanner. Back-torque the jam nut<\/strong> against the primary nut in the loosening direction using a second spanner \u2014 applying the specified jam nut torque (typically 50\u201380% of primary nut torque).<\/p>\n

      Step 4<\/strong> \u2014 The opposing torque loads generate a tensile preload in the bolt shank between the two nuts \u2014 compressing the thread flanks of both nuts against the bolt thread in opposing directions and creating the mechanical lock.<\/p>\n

      \n

      \u26a0\ufe0f Common installation error:<\/strong> Tightening the jam nut first and then the primary nut on top reverses the loading direction and significantly reduces locking effectiveness. Always install jam nut first, primary nut second.<\/p>\n

      Complementary Products<\/h4>\n

      Customers sourcing Hex Jam Nuts from Asia Bolts Industries frequently specify alongside:<\/p>\n

        \n
      • Standard Hex Nuts<\/strong> \u2014 DIN 934 full-height primary nut for double-nut assemblies<\/li>\n
      • Heavy Hex Nuts<\/strong> \u2014 ASTM A194 2H for high-pressure stud bolt double-nut assemblies<\/li>\n
      • Stud Bolts<\/strong> \u2014 ASTM A193 B7 for process flange and pressure vessel connections<\/li>\n
      • Threaded Rods<\/strong> \u2014 DIN 975, DIN 976 for rod extension and levelling assemblies<\/li>\n
      • Coupling Nuts<\/strong> \u2014 DIN 6334 for threaded rod extension with jam nut locking at joint<\/li>\n
      • Plain Flat Washers<\/strong> \u2014 DIN 125, F436 for load distribution under primary nut<\/li>\n
      • Anchor Bolts<\/strong> \u2014 complete anchor bolt packages with double-nut locking at base plate<\/li>\n
      • Wedge Locking Nuts<\/strong> \u2014 for critical vibration applications requiring positive mechanical lock<\/li>\n<\/ul>\n

        Asia Bolts can supply complete double-nut fastener packages<\/strong> \u2014 primary hex nuts, jam nuts, washers, and studs or threaded rods \u2014 from a single ISO certified source for construction, civil, structural, and process plant project procurement.<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

        Hex Jam Nuts<\/span><\/strong> \u2014 also known <\/span>as <\/span>Thin Hex Nuts, Half Nuts<\/span><\/strong>, or <\/span>Lock Nuts<\/span><\/strong> \u2014 by Asia Bolts <\/span>Industries are <\/span>reduced-height hexagonal nuts designed <\/span>to be threaded onto a bolt or <\/span>stud and tightened <\/span>against a standard hex nut <\/span>or mating surface to <\/span>create a mechanically <\/span>locked double-nut assembly that <\/span>resists self-loosening <\/span>under vibration, dynamic <\/span>loading, and thermal <\/span>cycling. The jam nut \u2014 torqued <\/span>against the primary nut in <\/span>the opposing direction \u2014 creates a <\/span>compressive preload between <\/span>the two nuts that locks both in <\/span>position, eliminating <\/span>relative rotation between the nut and <\/span>bolt thread without requiring any <\/span>additional locking elements, adhesives, <\/span>or deformable inserts.<\/span><\/p>\n

        Available in <\/span>standard thin hex (DIN 439), chamfered thin hex (DIN 936)<\/span><\/strong>, and <\/span>heavy hex jam nut<\/span><\/strong> variants, <\/span>manufactured to <\/span>DIN 439, DIN 936, ASME B18.2.2, ISO 4035<\/span><\/strong>, and <\/span>ASTM A563<\/span><\/strong> standards in carbon steel, stainless <\/span>steel, alloy steel, brass, and duplex <\/span>grades across metric and imperial <\/span>thread forms. All Hex Jam Nuts are <\/span>produced at our <\/span>Dubai Investment Park<\/span><\/strong> facility <\/span>under <\/span>ISO 9001, ISO 45001, and ISO 14001<\/span><\/strong> certified quality systems and exported <\/span>to <\/span>70+ countries<\/span><\/strong> across the GCC, <\/span>Middle East, Africa, and Asia.<\/span><\/p>\n

        \u2705 <\/span>DIN 439 thin hex & DIN 936 chamfered <\/span>variants available<\/span>
        \n\u2705 Carbon steel, <\/span>stainless steel, brass, alloy & duplex <\/span>grades<\/span>
        \n\u2705 Standard & heavy hex jam nut <\/span>configurations<\/span>
        \n\u2705 Full double-nut <\/span>locking assembly supply on request<\/span>
        \n\u2705 <\/span>Full MTC documentation & batch <\/span>traceability provided<\/span>
        \n\u2705 ISO 9001 \u00b7 <\/span>ISO 45001 \u00b7 ISO 14001 certified<\/span>
        \n\u2705 <\/span>Approved vendor: Saudi Aramco | ADNOC | <\/span>SABIC<\/span><\/p>","protected":false},"featured_media":1055,"template":"","meta":{"_kadence_starter_templates_imported_post":false},"product_brand":[],"product_cat":[34],"product_tag":[91,92,93,94],"class_list":["post-1482","product","type-product","status-publish","has-post-thumbnail","product_cat-nuts","product_tag-din-439","product_tag-din-936","product_tag-hex-jam-nuts","product_tag-iso-4035","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product\/1482","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media\/1055"}],"wp:attachment":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media?parent=1482"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_brand?post=1482"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_cat?post=1482"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_tag?post=1482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}