1. Purpose: 
circles from superhard materials (SHM) are intended for highly efficient turning and grinding of metal-and woodmachining tool from sintered alloys and steel, and also cutting shift polyhedral plates on specific universal- turning, flat- and circle-grinding machines. 
Recommended for using in mechanical engineering, instrument-making industry and woodworking. 
Distinctive circle characteristics is a presence of two contignous grinding layers (Fig.1.). Material characteristics of external circle layers is up to the conditions of highly efficient grinding, internal - to the conditions of finishing grindings. 
Each of the layers is produced on definite binder that povides their cyncronous wear during machining in total with given marks, granulerity and concentration of synthetic diamonds and cubic boron nitride. 

Fig.1. Fragment of working surface of two-layer circle for face grinding:  1 - layer from large-granulated grinding powder SHM on high-modulus metallopolymeric binder;  2 - layer from small-granulated grinding powder SHM on antifrictional self-labricated polymeric binder.

2.Circle forms and sizes:

Form and definition	D	H	S	b	b1	d
	100	32  34	3  5	5	2	20
	125	40  42	3  5	10	5	32
	150	40  42	3  5	10	5	32
	200	50  52	3  5	20	10	76
	125	12  14	1,5  3	6	3	32
	125	18	6	5	2,5	32
	100	24	3	5	2	20
	125	23  25	3  5	10	5	32
	150	23  25	3  5	10	5	32
		23  25	3  5	20	10	32
	100		5	8	4	20
	150		5	10	5	32
	200		5	20	10	76

3. Advantages: 
in comparison with standart one-layer circles form SHM on organic binder, two-layer circles provide a rise of machining productivity in 1,5-2,5 times in account of possibility of operational combinations, increasing of grinding depth and their self-turning and cutting ability.