Product Description - Offering best drill collars for drilling operations in oil and gas extraction (Slick and spiral Drill Collars, with slip and elevator recesses according to customer's request). Product origin - Sumy, Ukraine - UA Key Specifications/Special Features - Certification and standards: API Spec 7-1, API Spec 7-2, Q1 and ISO 9001, ISO 29001 and NS-1 Slick and spiral Drill Collars, with slip and elevator recesses according to customer's request Steel grade: AISI 4145H mod, fully heat treated as per API Specification At customer request it is possible to produce Drill Collars from non-magnetic and H2S resistant steel grades Technical parameters OD: from 79,4 mm (3 1/8) up to 279,4 mm (11) Length: 8300 mm, 9145 mm and 9450 mm, at customer request the length can vary from 6500 mm up to 12500 mm Standard API and double shouldered thread connections are made with stress relieved elements, cold rolled and phosphated, and equipped with pressed steel or heavy duty plastic thread protectors at both ends Hard banding of ARNCO 350XT, Castolin OTW 13CF, tungsten carbide Ultimate tensile strength: min 140 000/965 ksi/mPa, Yield strength: min 110,000/758 ksi/mPa, Elongation: 15%, Impact strength: min 48J, Brinell hardness: min 285-341 HB Mechanical properties guaranteed to 1 below steel surface.