some features of spiral drill collars

It is well-known that drill collars are processed with AISI 4151 H chromium molybdenum alloy steel. And the mechanical properties meet API SPEC 7-1 requirements, and the physical properties are guaranteed one inch below the surface at ambient room temperature. And all API connections obey dimensional requirements specified in API SPEC 7-1 guidelines.

In order to avoid differential pressure in the hole, the drill collar surface can be offered with three spiral grooves to reduce the contact areas with the wall of the hole. And the spiral grooves make mud circulate freely to equalize pressure around the drill collars and prevent a seal from forming. Compared with slick drill collars, the weight loss is approximately 4%.

API stress relief features and API bore box decrease the fatigue failures frequency through improving the bending strength of pin and box connections, which reduce high stress concentrations. Moreover, stress relief features are in compliance with API SPEC 7-1 standard.

Inquiries and orders, please consider below specifications:
OD, bore, length, slick or spiral, connection size and type, pressed or cast steel thread protectors, API stress relief features on pin and box ends, hard banding and any special features

• All drill collars from AGICO comply with API standard in inspection. The inspections include visual dimensional checks and ultrasonic inspection on each bar over its full length and section.
• Mechanical properties inspection in verified on samples;
• Inspection on each drill collar like thread profile, taper, pitch and standoff to all applicable API specifications and recorded;
• Traceability of Drill collars from product to process is maintained from receipt of mill certified raw material to all the processing completion. Each drill collar marked unique product number is for traceability;
• In addition, complete documentation is provided with each shipment details the full quality control records.