For optimizing centerless grinding processes, the selection of truing technology is important. The truing technology should provide stable, repeatable grinding wheel sharpness and an accurate profile.

CRI can provide both steady type truing tools and power driven diamond roll technology for centerless infeed and thrufeed grinding applications. In a partnership with Stroh Diamantwerkzeuge KG, www.stroh-diamant.de, an excellent German diamond tool manufacturer, superior quality and precision can be applied on CRI centerless grinding applications.

Single point diamonds are used primarily for straight wheels on centerless grinders and are mainly used on smaller size grinding and regulating wheels. The single point diamond tools that CRI stocks are 0.25 average carats weight with 7/16 shank size.

Single needle man-made diamond tools are used on narrow grinding and all regulating wheel applications. The advantage is that no diamond rotation is needed; the accurate square needle has a constant area of diamond contact, greatly benefiting truing repeatability. The wear range is 3-5mm dependant on needle size. Single needle diamonds can be ordered in sizes from 0.4-0.5-0.6-0.8mm. CRI stocks SN811-05C (0.5mm) and SN811-08C (0.8mm) with 7/16 shanks. These tools have proven excellent replacements for single point diamond tools for truing the regulating wheels; no rotation needed.

Blade type needle diamond tools with single row or multiple rows of needle shape diamonds. There are two types of diamonds tools available, the natural needle and man-made needle tools. CRI stocks the natural needle types (see stock list). Man-made can be supplied on request when high precision truing is required. The natural needle diamond layered tools are recommended for straight truing as well as stepped profile infeed applications where tool change is a problem and low initial truing tool cost is desired. These tools are designed so that when the first layer of needles is consumed the next layer is exposed by the truing operation. The number of needles in a row is dependant on grinding wheel diameter and width. For large size wheels such as for Cincinnati 340-20 a special double blade style with a special holder has been developed, which provides rough and final dress all in one pass. For selection of the proper size blade type truing tool see the Stroh Diamond Tools catalog.

Cluster diamond tools are impregnated particle diamond tools. These tools expose continuously new particle diamonds as the tool wears. These versatile tools are suitable mainly for straight wheel truing applications. CRI stocks 1.0 Carat tool with 7/16 shank. It is important is to specify the holder angle (0, 10, or 15 degrees).

Plunge type diamond rolls are manufactured by Stroh Germany with a step relation accuracy of +/- 0.000040 inch tolerance. Axial tolerance can be as low as +/-0.000080,angle tolerance as low as +/-1 minute and radii to +/-0.000080. This excellent quality guarantees a minimum error in geometry of the workpiece allowing more freedom for holding accurate size tolerances and very fine surface finish. CRI will review diamond roll drawings before manufacturing to guarantee the best possible quality. 

CNC contour truing diamond rolls are designed by CRI to suit the application and manufactured by Stroh. Four types of technology are available. Sintered diamond impregnated rolls, sintered with natural needles, brazed inserts of man-made diamond (PCD), and brazed needle man-made CVD. Depending on many variables, the application, as well as workpiece geometry, the correct profile will be designed and accordingly the selection made for the type of diamonds to be applied.