Roschen DTH Button bits are interchangeable with Atlas Copco's COP32 34 44 54 64 84, Ingersoll-Rand 's DHD3.5,DHD3.5HD, DHD 340A , DHD350R, DHD 360, DHD380 QL40, QL50 , QL60, QL80.NUMA100, NUMA120, MISSION60,ect. Description: (1) Made from premium quality nickel-alloy steel 25SiMnCrNi2MoVA for increased durability and wear characteristics, and YK 05 tungsten carbide as same grade as internationally well-known brand. (2) Apply "hot (thermal) -insertion" processing procedure to insert the buttons as same as internationally well-known brand, (4) Entire CNC processing procedure ensure the quality consistency and reliable. (5) Military grade requirements of heat-treatment guarantee durability, Specific heat treatment standards and special "stress relief" processes ensure consistent performance. (6) Designed for maximum performance and hole cleaning ability and high penetration rate. Matching the insert to the job requirements is essential in achieving the desired results. Each of the following buttons is ideal for different ground conditions, abrasion levels, PSIs and penetration levels. In general, the larger the number of gauge buttons the better overall performance, especially in hard rock.