ASTM A453 Gr. 660 Bolts

ASTM A453 Gr 660 is an important material specification for high-strength stainless steel bolting (bolts, studs, and nuts) designed for high-temperature, high-stress service. The fasteners governed by this specification are used in the most important joints in gas turbines, boilers, pressure vessels, and industrial pipeline flanges. Where connection integrity is critical to safety and reliability of operation, this specification provides guidance.

The fastener’s excellent performance comes from the specified base material: Alloy A286 (UNS S66286). Alloy A286 is not a standard stainless steel. Rather, it is an iron-based, precipitation-hardening superalloy. Its unique combination of raw materials, which include nickel and chromium as its primary alloying elements, along with molybdenum and titanium as secondary elements, provides A286 with very good strength, good creep resistance, and excellent oxidation resistance at continuous operating temperatures up to 700°C (1300°F). Also, its coefficient of thermal expansion is similar to the common austenitic stainless steels, making it a good candidate for use with many various types of other metals in mixed metal assembly applications.

An interesting aspect of the ASTM A453 Grade 660 specification is that it distinguishes it from American national Fastener standards through the specification of four different levels of properties. Each of the property classes (A, B, C, and D) is achieved through a specific, and controlled heat treatment cycle that is used for each of the fastener classes, thus allowing design engineers to select a fastener with specific desired mechanical properties. For example, any desiring to maximize yield strength for instance would certainly want to select ASTM A453 Gr 660 for any fasteners.

A453 Gr.660 stainless steel fasteners achieve their superior high-temperature properties through a multi-stage heat treatment process known as precipitation or age-hardening.

1. Solution Annealing: The material is heated to a high temperature (around 980°C / 1800°F) to dissolve the hardening elements into a uniform solid solution.
2. Quenching: The material is rapidly cooled to lock this structure in place.
3. Age Hardening: It is then reheated to a lower temperature (around 720°C / 1325°F) and held for an extended period (approx. 16 hours). This causes fine secondary-phase particles to “precipitate” out of the solution, which strengthens and hardens the alloy.

“Contact Jade Special Metals today with your requirement for ASTM A453 Gr. 660 Bolts. We assure you of the best quote.

ASTM A453 Grade 660 is a material specification based on the high-performance superalloy known as Alloy A286 or by its UNS designation, S66286. While different international standards may have unique names or designations, they often refer to a material with a very similar chemical composition and mechanical performance.

Oil & Gas Industry: Specified for the measured strength and corrosion resistance in critical downhole tools, wellhead components and high-temperature processing equipment.
High-Performance Automotive: A453 GR.660 Fasteners are ideal strapped down turbo chargers, exhaust manifolds and other engine components that must withstand extreme temperature cycle with minimal loss in clamping force.

• Specialist Manufacturer: As an experienced manufacturer of A453 660 Bolts, we have direct control over the entire production process, ensuring every fastener meets the highest quality standards.
• Certified Quality: Every order is backed by a Mill Test Certificate (MTC) as per EN 10204 3.1, guaranteeing full compliance with chemical and mechanical requirements for your peace of mind.
• Complete Product Range: We supply a full range of A453 Grade 660 bolts, studs, and nuts in all property classes (A, B, C, & D), simplifying your procurement process.
• Competitive Price: Our direct-to-market manufacturing model eliminates middlemen, allowing us to offer a highly competitive price without sacrificing certified quality.
• Proven Global Exporter: With a robust logistics network, we handle all documentation to export ASME SA-453 Grade 660 fasteners reliably to clients worldwide.