Duralite Brake Blocks by Raybestos-Raymark
Product Description
Duralite brake blocks were a line of friction braking components manufactured by Raybestos-Raymark, a company that operated for decades as one of the United States’ dominant producers of automotive and industrial friction materials. Raybestos-Raymark—known at various points in its corporate history under the Raybestos and Raymark Industries names—built its product catalog around brake linings, clutch facings, and related friction components sold to automotive, manufacturing, and heavy industrial markets across North America.
Duralite brake blocks were designed for use in industrial braking applications, where reliable friction performance under sustained mechanical stress was a primary engineering requirement. The “Duralite” designation reflected the product’s positioning as a lightweight yet durable braking solution intended for machinery, conveyors, hoists, cranes, and similar industrial equipment. These blocks were sold to manufacturers, industrial facilities, and maintenance operations that relied on consistent stopping power in demanding environments.
Raybestos-Raymark marketed friction products aggressively through trade catalogs and industrial supply channels throughout much of the twentieth century. The company’s manufacturing operations were concentrated in facilities in Stratford, Connecticut, and elsewhere, where large workforces produced friction components in high volumes. Duralite brake blocks were among the many Raybestos-Raymark branded products that carried asbestos as a primary functional ingredient during the decades when asbestos-reinforced friction materials were standard across the industry.
Asbestos Content
Asbestos was used extensively in brake and friction products manufactured by Raybestos-Raymark because of the mineral’s unique physical properties. Chrysotile asbestos, along with other asbestos fiber types, provided heat resistance, tensile strength, and friction stability that manufacturers could not easily replicate with alternative materials available at the time. In brake blocks, asbestos fibers were woven or compressed into the friction matrix, where they acted as both a structural reinforcement and a thermal buffer capable of absorbing and dissipating the intense heat generated during braking.
In Duralite brake blocks, asbestos content was integral to the product’s composition rather than incidental. The friction blocks were formulated to withstand the repeated heat cycles of industrial braking operations, and asbestos fibers were a core component of that formulation. Litigation records and trust fund documentation associated with Raybestos-Raymark products confirm asbestos as a primary material constituent across the company’s friction product lines, including brake blocks manufactured under the Duralite name.
Raybestos-Raymark’s internal documents, made available through litigation discovery, have been cited as evidence that company management was aware of the health hazards associated with asbestos at a relatively early date—yet the company continued to manufacture and sell asbestos-containing friction products for many years. This history forms a significant part of the legal record that led to the establishment of the Raymark Industries Asbestos Settlement Trust.
How Workers Were Exposed
Workers who encountered Duralite brake blocks faced asbestos exposure primarily through activities that disturbed the friction material and released airborne asbestos fibers. The nature of brake block use in industrial settings meant that these products were regularly installed, adjusted, inspected, and replaced as part of routine maintenance. Each of these tasks created opportunities for fiber release.
Installation and fitting involved cutting, grinding, or drilling brake blocks to achieve proper fit within machinery brake assemblies. These operations generated significant quantities of asbestos-laden dust that could remain suspended in the air of enclosed maintenance areas for extended periods.
Inspection and wear assessment required workers to handle worn brake blocks, which had often become friable—meaning the material had degraded to a point where fibers could be released by simple handling or light disturbance.
Removal of worn blocks was among the most hazardous tasks, as degraded friction material that had been subjected to repeated heat cycles could shed asbestos fibers readily when disturbed. Workers using compressed air to clean brake assemblies, a common industrial practice for many years, could generate concentrated clouds of asbestos dust.
Proximity exposure affected workers who were present in the same industrial spaces where brake block maintenance occurred, even if they were not directly involved in the work. Machinists, assemblers, machine operators, and general maintenance personnel in facilities that used crane, hoist, conveyor, or other equipment equipped with Duralite brake blocks may have inhaled asbestos fibers without performing any direct work on the components themselves.
The bystander exposure risk was compounded in industrial settings where ventilation was limited and where multiple maintenance tasks involving asbestos-containing materials might occur simultaneously. Workers who handled Duralite brake blocks repeatedly over the course of a career accumulated cumulative asbestos exposure that medical and epidemiological evidence links to the development of serious diseases, including mesothelioma, asbestosis, and lung cancer.
OSHA regulations establishing permissible exposure limits for asbestos were not implemented until the 1970s, meaning that workers who handled Raybestos-Raymark brake products during the peak production decades of the mid-twentieth century typically did so without regulatory protections, respiratory equipment, or warnings about the health hazards of asbestos inhalation.