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    12-Point Bolts in Stainless Steel

    12-Point Bolts in Stainless Steel, TorqBolt 12-point fastener with tB ligature and alloy grade marking

    TorqBolt manufactures 12-point stainless steel bolts in A286 and other compatible alloys to AS9100D and ISO 9001:2015 quality systems. Each fastener head carries the struck tB manufacturer ligature plus the A286 (or specified) alloy grade marking for traceability. Common applications include marine hardware, chemical processing, food handling, and corrosion-resistant aerospace structural fastening.

    Materials

    Alloy choice is set by the spec, the service temperature, the corrosion environment, and the strength target. TorqBolt routinely produces 12-point stainless steel bolts in A286 (UNS S66286), Inconel 718, Ti-6Al-4V (Grade 5), MP35N (UNS R30035), Custom 465 stainless, AISI 8740 chromoly heat-treated, AISI 4340, 17-4 PH H1025 condition, H-11 tool steel, and L19 race-grade alloy steel.

    Frequently asked questions

    What is a 12-point bolt?

    A 12-point bolt has 12 splines arranged every 30 degrees on the OUTSIDE of the bolt head, also called a bi-hex or double-hex bolt. The 12 external splines provide twice the wrench-engagement angles of a standard hex head, allowing higher applied torque before cam-off, which is why aerospace and motorsport applications adopt the geometry.

    Are 12-point bolts the same as ISO 14579?

    No. ISO 14579 specifies an INTERNAL hexalobular socket head (similar to Torx) recessed inside a cap screw. External 12-point bolts under MS21250 / NAS1351 / AS3216 use an EXTERNAL bi-hex head driven by a 12-point socket wrench. Both involve 12 features but on different sides of the bolt head and require different drivers.

    Which alloys does TorqBolt manufacture 12-point bolts in?

    TorqBolt produces 12-point bolts in A286 (UNS S66286), Inconel 718 (UNS N07718), Ti-6Al-4V Grade 5, MP35N (UNS R30035), Custom 465 H1025, AISI 8740 chromoly heat-treated, AISI 4340, 17-4 PH, H-11 tool steel, and L19 race-grade alloy steel. Choice depends on tensile target, service temperature, and corrosion environment.

    Is TorqBolt AS9100D certified?

    Yes. TorqBolt operates under AS9100D Rev D and ISO 9001:2015 quality management systems, audited annually by the registrar. NORSOK M-630 and NACE MR0175 / ISO 15156 qualifications cover offshore and sour-service applications. Mill test reports MTC 3.1 standard and MTC 3.2 critical-service witness are issued with every lot.

    What lead time should I expect?

    Stock alloys (A286, AISI 8740, AISI 4340, 17-4 PH, 316 stainless) ship in 4 to 6 weeks. Specialty alloys (Inconel 718, MP35N, Custom 465, Ti-6Al-4V, L19) ship in 8 to 12 weeks depending on raw-bar lead time at the alloy producer. Critical-service orders requiring third-party witness inspection (MTC 3.2) add 1 to 2 weeks for witness scheduling.

    Stainless 12-point alloy decision

    Stainless steel 12-point bolts cover three primary alloys: A286 (UNS S66286) at 160 ksi for aerospace and high-temperature applications to 700 deg C, 17-4 PH H1025 stainless at 180 ksi for corrosion-resistant precipitation-hardening structural service, and 316 austenitic stainless at 75 ksi for marine and food-grade applications where the joint sees neither high tensile nor high temperature. A286 dominates aerospace; 17-4 PH dominates marine and chemical processing; 316 dominates food and pharmaceutical fastening.

    For higher tensile in stainless families see Inconel 718 at 180 ksi for jet engine duty, MP35N at 260 ksi for sour-service oil-gas, and titanium Ti-6Al-4V at 130 ksi for weight-critical aerospace structural service. Specs: NAS1351, MS21250, AS3216. Dimensional: UNJ-3A thread chart.

    Request a Quote

    RFQ to info@torqbolt.com, call +91-22-66157017, or WhatsApp +91-22-66157017. Mill test report (MTC 3.1 standard, 3.2 critical-service) ships with every lot.