In-cycle hole deburring down to 1 mm diameter with Mollart’s hole solution

The tools can be incorporated into CNC lathe and machining centre cycles as well as special purpose machine tools and, depending on the operational circumstances, can be used in conjunction with power tools and by hand. The E-Z Burr concept is ideal for chamfering and removing burrs from cross holes and hole breakthroughs, combined front and rear chamfering of bores, internal grooves and recesses, fabrications and internal surfaces such as within box sections. Graphic simulations of E-Z Burr Tools can be viewed on www.bencere.co.uk where the advantage and operation of the patented two-piece design of the tool and solid arbour style holder can be appreciated. The tools, which are available from Mollart Bencere in Stratford-upon-Avon, comprise an extended blade, having either one or two cutting edges, that are located via a dovetail in the holder. The dovetail, which also acts as a fulcrum, enables the cutting blade to become a flexible arm pivoting in the holder. There is a choice of solid carbide or high speed steel (HSS) blade. Both can be changed within a few seconds on the machine tool without upsetting the chamfer setting on the component by a simple one-eighth counter-clockwise movement of a lock screw on the side of the holder. The solid carbide tool can also be used on heavy burrs at elevated cutting speeds that are at least three times greater than the HSS version. Tough and exotic materials as well as non-ferrous can be machined and due to the durability of the carbide and the TiN coating, tool life should be some five-times greater than the HSS version. In use, the tool is fed into the workpiece and as the extended blade contacts and cuts the burr at the front, its spring-like action around the lock screw allows it to slide back into the holder. Once the blade has retracted completely, the tool is able to continue through the bore of the component and due to the polished crown on the top of the blade, there is no marking or scoring of the hole. Once the tool clears the back of the bore, the blade and cutting edge flexes back out of the holder and as the direction of feed is reversed, any rear burr or chamfer is cut as the tool begins to withdraw. With the cutting cycle complete and the blade once again fully retracted into the holder, the tool can be withdrawn under a rapid rate of feed. There are two styles of HSS and carbide blade with B catering for both front and rear cutting, while R is used for applications requiring only rear or back chamfering. The HSS blades are available with standard and positive cutting rake angles and the carbide inserts have a positive rake angle with a series of geometries to suit a wide range of materials. While the Bencere E-Z Burr HSS series of tools range from 1 mm to 50.8 mm diameter, the carbide tool version is suitable for diameters from 3.17 mm to 25.4 mm. Other sizes of tools are available for larger bores as well as customised and combination tools that are able to provide combined drilling and deburring from the same tool position.