Issue link: http://www.e-digitaleditions.com/i/206043
API Chains, Features and Benefits Fatigue Strength Inspire Series™ Former SBR® Compressive Residual Stress Zones Compressive stress has long been known to improve fatigue strength. Sources of compression in existing chain products include shot peening, high interference fits between pins, bushing and side plates, and the carburized zone found on pins and bushings. Competitive Brand Our unique patent pending "Hi-Energy Mechanical Treatment" imparts substantial compressive stresses to the chain components (see chart below) resulting in a 45%-50% increase in fatigue strength. Horsepower ratings as well as the rated working loads are the highest in the world. 0 50 100 150 Relative Percentage Compressive Residual Stress Measurements 200 Inspire Series™ Pin vs. Standard Carburized Pin Triple Zone Hardness Wear Protection 1. Ultra-high hardness shell (Black Zone - See Below) 2. High hardness carburized case (Blue Zone - See Below) 3. Core hardness (Orange Zone - See Below) Inspire Series™ Compressive Stress (PSI) Thousands A residual, but important benefit of Hitachi's new "Hi-Energy Mechanical Treatment" is that an ultra-high hardness shell is developed on the surface of carburized pins. This effectively gives these wearing components three layers of hardness protection: 50 Standard Pin 0 -50 -100 -150 -200 Surface .001" .002" .003" .004" .005" .006" .007" .008" Depth From Surface (inches) Compressive stress measurements. The deeper trough of the INSPIRE SERIES™ SBR® pin means that the part has more compressive residual stress and is therefore more resistant to fatigue failure. Micro Hardness Measurements Benefits Summary Greater resistance to fatigue failure. Longer wear life due to high hardness shell. Inspire Series™ 75 70 Black Zone Blue Zone Standard Pin Core Zone 65 Hardness (Rc) Micro hardness measurements of the pins reveal an ultra-hard shell which fights chain elongation far better than can be achieved with conventional carburized parts. 60 55 50 45 Smaller chain sizes required (Higher HP ratings). 40 Corrosion protection from proprietary stainless blast. Surface .002 .004 .006 .008 .010 .012 .014 .016 .018 .020 .022 Core Depth from Surface (inches) 2