Marcrist PC850 Diamond Core Drill Head Piece 117mm x 165mm. The Marcrist PC850 Diamond Core Drill delivers lightning-fast drilling performance without breakout, and without the need for special machinery. This versatile core bit can drill dry through materials ranging from common brickwork to hard concrete, making it an essential tool for professional tradespeople and serious DIY enthusiasts alike. Engineered in the UK to tackle the hardest materials, this universal diamond core bit is ideal for everyday use by plumbing, heating and electrical specialists. It drills hard materials which previously could not be drilled dry, completing holes in 2½ minutes that traditionally took more than 14 minutes. Drills hard materials which previously could not be drilled dry. Engineered in the UK for the hardest of materials. Drills in 2½ minutes what traditionally took more than 14 minutes. Must have for professional plumbing, heating, electrical engineers. For use on diamond and/or percussion drilling machines. Diameter: 117mm Length: 165mm. PLEASE SEE MY OTHER LISTINGS.