API 7-1 Non Mag drill collar for oil&gas downhole drilling

The Non-magnetic drill collar is made of a kind of low carbon high chrome-manganese alloy steel, which is refined after strict chemical composition ratio and forged to achieve its mechanical properties, this kind of drill collar has superb mechanical properties of low permeability and high strength. Mainly used for downhole drilling.

Our Strict control of chemical composition and special forging process guarantee the excellent mechanical properties of our non magnetic drill collar.

Connection Type	OD		ID		Length (ft)
Connection Type	mm	in	mm	in	Length (ft)
NC23-31	79.4	3 1/8	31.8	1 1/2	Available from 10 to 31 ft
NC26-35(2 3/8 IF)	88.9	3 1/2	38.1	1 1/2
NC31-41(2 7/8 IF)	104.8	4 1/8	50.8	2
NC35-47	120.6	4 3/4	50.8	2
NC38-50(31/2IF)	127	5	57.2	2 1/4
NC44-60	152.4	6	57.2	2 1/4
NC44-60	152.4	6	71.4	2 13/16
NC44-62	158.8	6 1/4	57.2	2 1/4
NC44-62(4IF)	158.8	6 1/2	71.4	2 13/16
NC44-65(4IF)	165.1	6 1/2	57.2	2 1/4
NC44-65(4IF)	165.1	6 1/2	71.4	2 13/16
NC44-67(4IF)	171.4	6 3/4	57.2	2 1/4
NC50-672(41/2IF)	171.4	6 3/4	71.4	2 13/16
NC50-70(41/2IF)	177.8	7	57.2	2 1/4
NC50-70(41/2IF)	177.8	7	71.4	2 13/16
NC50-72(41/2IF)	184.2	7 1/4	71.4	2 13/16
NC56-77	196.8	7 3/4	71.4	2 13/16
NC56-80	203.2	8	71.4	2 13/16
6 5/8 REG	209.6	8 1/4	71.4	2 13/16
NC61-90	228.6	9	71.4	2 13/16
7 5/8 REG	241.3	9 1/2	76.2	3
NC70-97	247.6	9 3/4	76.2	3
NC70-100	254	10	76.2	3
8 5/8 REG	279.4	11	76.2	3

MECHANICAL PROPERTIES AS PER ASTM A370
Item	Tensile Strength (Mpa)	Yield Strength 0.2% (Mpa)	Elongation%	Charpy Impact Work(J)	Brinell Hardness (HB)	Reduction Area(%)	IGC	Field Gradient (μT)	Relative magnetic per meability
Requested	≥827	≥758	≥25	≥122	≥285	≥50	/	±0.05	≤1.010
Actual	1135	1038	26	226	304	70	Pass	Pass	1.003

Advantages:

Increase the corrosion resistance properties;

Increase the surface hardness of bore up to HB400;

Increase surface finish of bore to Ra≤3.2μm

Test and inspection carried out on each bar during production :

Chemical Composition;

Tensile Test;

Impact Test;

Hardness Test;

Metallographic Test (Grain Size);

Corrosion Test (According to ASTM A262 Practice E);

Ultrasonic Test over the whole length of the bar (according to ASTM A388);

Relative magnetic permeability test;

Hot Spot Test;

Dimension Inspection, etc.

Specification of non magnetic drill collars

Tool Joint	OD in	Bore d in + 1/16 -0	Length ft +6 -0	Bevel Diameter in ±1/64 in	BSR
NC23-31	3 1/8	1 1/4	30	3	2.57:1
NC26-35	3 1/2	1 1/2	30	3 17/64	2.42:1
NC35-41	4 1/8	2	30 or 31	3 61/64	2.43:1
NC35-47	4 3/4	2	30 or 31	4 33/64	2.58:1
NC38-50	5	2 1/4	30 or 31	4 49/64	2.38:1
NC44-60	6	2 1/4	30 or 31	5 11/16	2.49:1
NC44-60	6	2 13/16	30 or 31	5 11/16	2.84:1
NC44-62	6 1/4	2 1/4	30 or 31	5 7/8	2.91:1
NC46-62	6 1/4	2 13/16	30 or 31	5 29/32	2.63:1
NC46-65	6 1/2	2 1/4	30 or 31	6 3/32	2.76:1
NC46-65	6 1/2	2 13/16	30 or 31	6 3/32	3.05:1
NC46-67	6 3/4	2 1/4	30 or 31	6 9/32	3.18:1
NC50-70	7	2 1/4	30 or 31	6 31/64	2.54:1
NC50-70	7	2 13/16	30 or 31	6 31/64	2.27:1
NC50-72	7 1/4	2 13/16	30 or 31	6 43/64	3.12:1
NC56-77	7 3/4	2 13/16	30 or 31	7 19/64	2.70:1
NC56-80	8	2 13/16	30 or 31	7 31/64	3.02:1
6 5/8 REG	8 1/4	2 13/16	30 or 31	7 45/64	2.93:1
NC61-90	9	2 13/16	30 or 31	8 3/8	3.17:1
7 5/8 REG	9 1/2	3	30 or 31	8 13/16	2.81:1
NC70-97	9 3/4	3	30 or 31	9 5/32	2.57:1
NC70-100	10	3	30 or 31	9 11/32	2.81:1
8 5/8 REG	11	3	30 or 31	10 1/2	2.84:1