Spiral drill collar is used to reduce contact area with hole so as to avoid efficiently bit sticking from differential pressur

Spiral drill collar is used to reduce contact area with hole so as to avoid efficiently bit sticking from differential pressure. spiral drill collars are manufactured strictly according to API Spec.7 and Standard SY5144, all mechanical properties meet with above standards.Spiral Drill Collar,drill collar,drilling collarSizes for drill collar spiral groove.

O.D.		Cutting depth		Lead±25.4
Mm	in	A(mm)	B(mm)	mm
86	3 3/8	3.5±0.79		679
98.4	3 7/8	4.0±0.79		914
101.6111.1	44 1/8	4.8±0.79		914
114.3130.2	4 1/25 1/8	5.6±0.79		965
133.4146.1	5 1/45 3/4	6.4±0.79		1067
149.2161.9	5 7/86 3/8	7.1±1.59		1067
165.1177.8	6 1/27	7.9±1.59		1168
181.0200.0	7 1/87 7/8	8.7±1.59	5.6±0.79	1626
203.2225.4	88 7/8	9.5±1.59	6.4±0.79	1727
228.6250.8	99 7/8	10.3±2.37	7.1±1.59	1829
254.0276.2	1010 7/8	11.1±2.37	7.9±1.59	1930
279.4	11	11.9±2.37	8.7±1.59	2032

Spiral Drill Collar,drill collar,drilling collar