Lowest price API 7-1 non magnetic spiral drill collar Product Description Drill Collar is the basic component in the BHA which provide weight on the bit for dirlling and keeps the drill string in tension.Drill collar is manufactured from AISI 4145H modified quenched and tempered steel and is heat treatment along its entire length for uniform toughness and durability. Srict netallurgical test are performed pre specifications to ensure that the heat treatment produces consisitent and maxium hardness through the depth of the bar. Feartures and benefits: 1. hardness rannge of 285 to 341 BHN and a charpy impact value of 40ft/lbs are guaranteed for evenly distributed 16 points in any cross sections at room temperature 2.Connections ar phosphate coated afther machinning to protect the threads from corrosive elements and to prevent galling upon initial make -up Thread roots are cold rolled on API and H0-90 connections 3.Pressed steel thread protectors are supplied fo all drill collar that are equipped with standard connections