Engineering Reference

Precision Ball & Roller Bearings
(Medium to Large Diameter)

Platings & Coatings

Plating and coating materials are typically used to help reduce surface wear and/or alleviate corrosion. The most widely specified plating material is Nodular Thin Dense Chrome (NTDC), more commonly referred to as “Thin Dense Chrome” or simply “TDC”.

Overview of Nodular Thin Dense Chrome (NTDC)

Nodular Thin Dense Chrome (NTDC) is a densified, nodular, chromium-rich material. It bonds to most substrates and is extremely hard (greater than 70 HRC). The unique micro-nodular surface features help to reduce the effective contact surface area, thereby lowering friction coefficients. The spaces between the nodular formations (microscopic scale) facilitate improved lubricant retention. Because of the unique application process, precise geometric tolerances can be maintained.

Consideration should be given to the processing temperatures. The NTDC material must be post baked to remove any unwanted hydrogen. Plus, the post bake temperature must be below the tempering temperature of the ring material to ensure that dimensional stability and surface hardness are maintained.

Please contact HiTech’s Applications Engineering department for details relating to other plating and coating options.