For superabrasive wheels, phenolic resin bonds represent the earliest, and most popular, bond type particularly for diamond wheels and especially for tool-room applications. The bonds were originally developed for diamond with the introduction of carbide tooling in the 1940s. Their resilience made them optimal for maintaining tight radii while withstanding the impact of interrupted cuts typical of drill, hob, and broach grinding. To prevent localized temperature rise, the abrasive is typically metal coated to act as a heat sink to dissipate the heat. In addition, high volumes of copper or other metal fillers may be used to increase thermal conductivity and heat dissipation.
Not surprisingly, phenolic resin bonds were quickly adopted with the introduction of CBN in 1969, and phenolic resin bonds predominate for the steel tool industry [Craig 1991].
6.10.5 Wheel Marking Systems for Resin Bonds
Because the basic technology is so mature, the number of wheel makers is too numerous to list. However, the marking system for wheels is covered by standards such as ANSI B74-13 shown later for the United States or JIS B 4131 for Japan [Koepfer 1994].
Many wheel makers are located close to specific markets to provide quick turnaround. Alternatively, many are sourced from low-cost manufacturing countries. The key to gaining a commercial advantage in this type of competitive environment is application knowledge either by the end user developing a strong database and constant training, or using the knowledge of the larger wheel makers with strong engineering support.