.: Juferma - Materiales para sondeos :.

As general rule the surface set bits require lower rotation speeds that those used in drilling with impregnated diamond bits . Lower speed how bigger the diamond stone is.
To calculate the rotation speeds, we recommend use a periferical speed from 1.0 to 2.5 meters per second.
The load on the bit is more important in surface set bit than the rotation speed.
The maximum weight on the surface set bit, to be calculated with the formula as follow:

Max. Weight = Cts x SPC x 3.3
Cts = weight in carats of the setting diamond in the surface bit. - SPC = stone per carat on the bit.

I.e: Bit 86 B with 40 spc set 13 cts.

Max. Weight = 13 x 40 x 3.3 = 1.716 Kgs.

DRILLING PARAMETERS - Indicative values
	METRIC SIZE mm									WIRELINE SIZE
	46	56	66	76	86	101	116	131	146	BQ	NQ	HQ	PQ
ROTATION r.p.m.	1000	900	700	600	500	400	300	200	200	700	600	400	300
BIT LOAD KN.	7	8	11	12	15	20	22	24	26	15	20	25	30
FLOW Lit/min	14	16	20	25	30	40	50	60	70	20	30	40	55