The main requirements of bearing steel are high hardness, elastic properties, Resistance to fatigue and contact fatigue failure. These requirements are satisfied by high carbon alloy steels

Chemical Composition
Bearing steel has carbon content in the range of 0.55 to 1.10 percent, manganese, silicon, phosphorus and sulfur up to a maximum of 0.03 percent and chromium in the range of 0.5 to 2.0 percent. The remaining percent is iron. The chemical properties determine the anti-corrosive properties of the bearing steel. The chemical composition of the steel also dictates its mechanical and physical properties such as the strength and hardness, toughness and brittleness and ductility and malleability.

Hardness
Bearing steel has enormous hardness. A minimum expected hardness for bearing components is 58 Rc Bearing steel has a bending strength of 2400 MPa (Pascal Unit) and can withstand high stress and centrifugal forces. But it has a low corrosion resistance
Carbon increases the strength of bearing steel. Strength ensures that parts (i.e., bearings) made from it do not deform on the application of stress and load. Ductility and weldability, however, decrease with increasing carbon content. In addition to this, bearing steel is designed to have high fatigue strength and life and needs to respond uniformly to the heat treatment process. It should have a compact structure with a consistent grain flow and a fine grain size that imparts high impact toughness to the alloy.

Physical Properties
Bearing steel is magnetic in nature and is a good thermal and electrical conductor. 

Titanium based alloys:
Due to their high strength to weight ratio and excellent corrosion resistance, Titanium alloys parts are ideally suited for advanced aerospace systems. Titanium based alloys which contain 86-99.5% Ti and 5-8% Al, are immune to almost every medium to which they would be exposed in an aerospace environment.
Today, Titanium is used extensively in commercial and military applications and to some extent in space. The primary areas of application for aircrafts are landing gear, landing-gear support structures, wing structures, vertical wing-actuation structures, engines, floor beams and seat-track architecture.
Very large usages of titanium can be found in jet engines, where titanium alloys parts make up to 25-30% of the weight, primarily in the compressor. The high efficiency of these engines is received through the use of titanium alloy components like fan blades, compressor blades, rotors, discs, hubs and other non-rotor parts like inlet guide vanes.Despite its higher cost relative to competing materials, primarily aluminum alloys and steels, the demand for titanium is projected to grow by at least 40-50% over the next few years. Titanium’s superior properties and light weight allow aeronautical engineers to design planes that can fly higher and faster with high resistance to extreme environmental conditions.

Machining Challenges:
Titanium, has historically been perceived as a material which is difficult to machine.
The machining difficulties are the result of the physical, chemical and mechanical properties of the metal.
The material’s relatively high temperature resistance along with its low thermal conductivity does not allow generated heat to dissipate from the cutting tool. This causes excessive tool deformation and wear. Titanium alloys retain their strength at high temperatures causing relatively high plastic deformation of the cutting tool resulting in depth of cut notches. During machining, the high chemical reactivity of titanium alloys causes the welding of the chips to the cutting tool leading to Built-up cutting edges and chip breakage problems. Over the past few years, ISCAR has invested a lot in R&D in order to investigate the machining of Titanium alloys. Our special improved cutting tools along with our unique grades have places ISCAR as a leading company in the area of machining titanium.
In addition to our standard pressure cooling solutions, the growing demands for high pressure machining solutions especially in the aerospace market, has led ISCAR to develop unique product lines suitable for high pressure cooling systems.
When machining Titanium alloys with standard pressure coolant, the recommended cutting speed is 60-70 m/min. The use of high pressure cooling system enables to increase the cutting speeds by 100-150% and significantly increase the productivity.

The excellent physical properties that characterize Nickel-based high temperature alloys make them ideal for use in the manufacture of aerospace components. Properties such as high yield strength and ultimate tensile strength, high fatigue strength, corrosion and oxidation resistance even at elevated temperatures, non-magnetic characteristics and low creep, enable the usage of Nickel-based high temperature alloys in many applications and over a very wide temperature spectrum. The aerospace industry accounts for about 80% of Nickel-based high temperature alloys which are used in rotating parts of gas turbines such as disks and blades, housing components such as turbine casing, engine mounts and in components for rocket motors and pumps. Nickel-based high temperature alloys, which contain 35-75% Ni and 15-22% Cr, constitute about 30% of the total material requirement in the manufacture of an aircraft engine, and are also used as structural material for various components in the main engine of space shuttles. With the introduction of Inconel 718 (which is one of the most common Nickel-based high temperature alloys in the aerospace industry) in the year 1960, its usage has seen a tremendous growth in the aircraft industry.

Machining Challenges:

The very same properties that make Nickel-based high temperature alloys such a great high temperature materials also cause high machining difficulties. Metallurgical characteristics like the hard abrasive particles in the materials’ microstructure and the high work hardening rates are primary reasons for the poor machinability.
The cutting forces and temperature at the cutting zone are extremely high due to the high shear stresses developed and the low thermal conductivity. This, coupled with the reactivity of Nickel-based high temperature alloys with the tool material, leads to galling and welding of the chips on the work piece surface and cause excessive tool wear, which can limit cutting speeds and reduce useful tool life. In addition, the high capacity of these materials for work hardening causes depth of cut notches on the tool.
All these characteristics contribute to low material removal rates and short tool life resulting in huge machining costs.
Over the past few years, ISCAR has invested a lot in R&D in order to investigate the machining of Nickel-based high temperature alloys. Our special improved cutting tools along with our unique grades have places ISCAR as a leading company in the area of machining Nickel-based high temperature alloys.
In addition to our standard pressure cooling solutions, the growing demands for high pressure machining solutions especially in the aerospace market, has led ISCAR to develop unique product lines suitable for high pressure cooling systems.
When machining Nickel-based high temperature alloys with standard pressure coolant, the recommended cutting speed is 30-35 m/min. The use of high pressure cooling system enables to increase the cutting speeds by 100-150% and significantly increase the pro