Premier pins are available in several profiles to suit the geometry of the unworn button: hemispherical, ballistic, parabolic and conical. All profiles are the combination type, where the carbide button and surrounding steel body are cut simultaneously to provide the most effective refurbishment of the bit in a single step.
Drive arrangements are standardized to suit most common grinding machines:
• Shoulder drive with one ‘O’ ring
• Atlas Copco Terroc 55
• Sandvik Sancone A
• Plain shaft
• Adaptors are available to suit other drive geometries
Premier has developed specific matrices to give consistent self-sharpening properties for either air or water flushed grinding processes. In either case, it is important to avoid overheating the carbide and creating new stress cracks.
Various waterway configurations are available: standard (single waterway), three waterway which is better suited to provide adequate flushing to the larger sizes and twin waterway to eliminate the “nipple effect” where an uncut nib is left in the centre of the button. This effect if not corrected, can result in cracking of the button when placed back in service, due to the concentrated load in the centre. Modified single and three waterway versions are also available to effectively address the “nipple effect”.