4 1/2" 8" 4145h and Alloy Steel Drilling Tool Non-Magnetic Drill Collars

4 1/2" 8" 4145h and Alloy Steel Drilling Tool Non-Magnetic Drill Collars. Spiral Design for Anti-Sticking: Three dextrogyrate spiral grooves reduce contact area and friction to prevent pressure sticking. Lightweight Construction: Single weight is approximately 4% lighter than ordinary drill collars of the same specification. High-Strength Alloy Material: Made from AISI 4145H modified alloy steel meeting Spec 7-1 and SY/T5144 standards. Enhanced Thread Strength: Special normalizing process refines grain structure to improve thread strength and service life. Wide Size Range Available: Available in sizes from 3-1/8 inch to 11 inch with various thread types including NC and REG. Superior Mechanical Performance: Yield strength up to 758 MPa and tensile strength up to 965 MPa for optimal durability. Custom Color Options: Color can be customized as per customer request. Strict Quality Control: Manufactured to international standards with rigorous QA and QC monitoring processes.