Cutting tools Staying Cool: Micro Drills for Highly Stable Machining
Germany — Walter has extended their range of solutions for precision micro-drilling with two new additions.
The series of internally cooled Walter Titex DB133 Supreme micro drills has been expanded with the DB133 Supreme solid carbide micro drill in dimensions of 5, 8 and 12XD. The through coolant DB133 Supreme features an AlCrN coating. The 5XD offering has WJ30EL full flute length coating applied. However, the longer 8XD and 12XD drills are WJ30ER with the coating only applied to the point of the drill and not the entire flute length, which further aids chip evacuation in deeper holes.
The Walter Titex DB133 drills feature a 140-degree point angle to ensure positive engagement in the pilot hole that is produced by DB131. The DB133 Series starts at 0.7 mm diameter, and increases in 0.05 mm increments to the largest drill in the range, 1.984 mm. The overall flute length of the 0.7 mm diameter 5XD, 8XD and 12XD drills is 6 mm, 8 mm and 11 mm and 17 mm, 23 mm & 31 mm respectively for the largest 1984 mm diameter 5XD, 8XD & 12XD drills. The entire programme is based upon a 3 mm diameter shank with all drills consisting of precision ground flutes and two coolant channels that maximise chip clearance and cooling performance.
The new DB131 Supreme drill is a pilot drill for deep hole drilling operations. It features the WJ30EL (AlCrN) coating which covers the complete flute length and it has a smooth surface offering secure chip evacuation. The point angle on the DB131 pilot drill is 150 degrees making it perfect for pilot holes up to 2XD prior to the deep hole drilling applications with the corresponding DB133 drill. The diameter ranges from 0.5 to 1.984 mm with 0.05 mm diameter increment increases, with common imperial equivalents also added to the program, and covering some small tap drill sizes. The flute length of the 0.5 mm drill is 3 mm and the overall length is 47 mm and this proportionately increases to a flute length of 10 mm and overall length of 57 mm on the 1984 mm diameter drill.
The result of a new flute design allows the chips to break, so that they are shorter, guaranteeing reliable evacuation from the work envelope. The new drills also incorporate a special cutting edge preparation that demonstrates outstanding surface finish and overall hole quality on the component whilst significantly improving tool life.
With these new products, Walter has further refined the adaptation of the length to diameter (L/D) ratio to the required drilling depth. The result is a range of micro drills that ensures maximum stability when machining thanks to its broad scope and the optimised design. The drill and pilot drill can be used with emulsion or oil and are suitable for all ISO material groups.
In addition to the watchmaking and jewellery industry and medical technology, the premium manufacturer cites general mechanical engineering, mould and die making, the electronics and the energy and automotive industries as other specific areas of application.