Under normal circumstances, brake discs should be replaced every 60,000 to 80,000 kilometres. Brake discs are a wearable part of a car's braking system, and as the car's mileage increases, the discs will continue to wear out. When brake discs wear down to a certain level they need to be replaced. The demand for brake disc replacement and machining increases every year with the increase in car ownership. The machining itself is not difficult, but how to ensure its surface quality and dimensional accuracy while making the cutting process more efficient and improving the efficiency of production depends largely on the choice of tools.

Common brake discs are made of HT250, with three main components (ratio): C:3.1-3.4 Si:1.9-2.3 Mn:0.6-0.9. Mechanical properties required: tensile strength >= 206MPa, flexural strength >= 1000MPa, deflection >= 5.1mm, hardness required between: 187-241HB. The processing of this type of material places a very high demand on the wear resistance of the processing tool. Due to the consideration of the actual use of the brake braking effect, the surface finish of the brake disc processing does not need to be too high, generally reaching Ra3.2μm is sufficient.

For the above common machining situations, WSS has tailored CBN tool material, which offers significant advantages over carbide in terms of machining efficiency, tool life and part quality and dimensions; Compared to other brands of CBN tools, WSS tools are very cost effective and stable, and offer a corresponding resharpening service, which can effectively reduce the customer's cost of use and cost per piece.

Our tools were tested at a customer who used a horizontal lathe to machine a brake disc made of HT250, with a workpiece hardness of around HRC 30, a diameter of D140 at the internal bore and D280 at the external circle, and a surface requirement of Ra3.2μm.

Tool and workpiece clamping methods

We use the CNMX120416 specification custom CBN material inserts and competitors to compare, respectively machining brake discs of the outer circle and end face, as well as internal holes and end face at the same parameters (as shown in the table), than an imported brand of CBN tool life, cost-effective advantage is obvious, and CBN tool for gray iron materials can achieve higher linear speed than the conventional carbide The linear speed of CBN tools for grey ferrous materials is higher than that of conventional carbide tools, which can achieve a higher efficiency beat and also ensure the maximum dimensional accuracy and surface quality of the parts. The excellent quality of our products is the cornerstone of WSS' customer recognition and trust, and we will continue to improve and develop more good products for our customers for this reason!