Good Quality Drill Collar for Borehole Drilling Rig

• Customization: Available
• Model: Glnc35
• Inner Length: 82.6mm
• Model NO.: Drill Collar
• Transport Package: Normal Sea Packing
• Specification: chromium-molybdemum alloy steel
• Trademark: Glorytek
• Origin: China
• Production Capacity: 3000PCS/Month

Product Description

Popular Spiral Drill Collar For Drill Rig Parts 

The spiral drill collars are made from 4145H modified chromium-molybdemum alloy steel acc. to API Spec.7 and SY/T5144.All threads are phosphated,copperized or cold worked.All connections are equipped with pressed steel thread protectors.All threads are machined with CNC lathes-Double-shouldered and special threads.

Tolerance of drill collars

OD size(mm)	OD size(inch)	OD	ID	Length	Bevel diameter(mm)
≤88.9	≤3 1/2	+1.20	+1.60	±152.4	±0.4
>88.9~114.3	>3 1/2~4 1/2	+1.60
>114.3~139.7	>4 1/2~5 1/2	+2.00
>139.7~165.1	>5 1/2~6 1/2	+3.20
>165.1~215.9	>6 1/2~8 1/2	+4.00
>215.9~241.3	>8 1/2~9 1/2	+4.80
>241.3	>9 1/2	+6.40

Stress-relief slot for connection

Connection	L ±1.59mm	Dcb+0.4 -0mm	±20.83mm/m	Drc+0 -0.79mm	Lrc+0 -3.18mm
NC35	82.6	82.15	166.67	82.15	85.73
NC38	88.9	88.11	166.67	89.10	92.08
NC40	101.6	92.87	166.67	95.81	104.78
NC44	101.6	101.60	166.67	106.36	104.78
NC46	101.6	106.76	166.67	109.93	104.78
NC50	101.6	117.48	166.67	120.45	104.78
NC56	114.3	121.84	250.00	134.04	117.48
NC61	127.0	132.95	250.00	148.31	130.18
NC70	139.7	152.00	250.00	170.54	142.88
NC77	152.4	166.29	250.00	188.01	155.58
6 5/8 Reg	114.3	134.14	166.67	137.59	117.48
7 5/8 Reg	120.7	148.83	250.00	161.26	123.83
8 5/8 Reg	123.8	172.24	250.00	185.45	127.00