Type 440C Stainless Steel is widely used in antifriction bearings, in valves and in many other applications where high hardness and reasonable corrosion resistance are required. This material is much more resistant to abrasion and wear than chrome steel. It is a high alloy, fine grain, through hardening, Martensitic stainless steel. Because of its high hardness and fine grain structure, it can be finished to a fine dimensional quality.
This material will harden to 58 rockwell "C" (58 HRC) minimum. The hardness is measured on parallel ground flats or the reading taken on the spherical surface is corrected for the curve. The HRC scale uses 150 kilogram load ( approximately 330 lb. ) applied to a conical diamond "brale" indenter.
of this material is .277 pounds per cubic inch ( 7.67 g/cm^3).
This material is strongly attracted by a magnetic field.
In the hardened condition, this material can be ground, honed, and lapped using conventional abrasives. It can be shaped and drilled using electric discharge machining or ultrasonic cavitation. In the annealed condition this material can be machined using normal techniques.
Because this material has 1% carbon, it is difficult to obtain a quality weld. It can be resistance welded with difficulty. It can be soft soldered with a high tin solder using an acid flux. It can be silver soldered or brazed, but the heat will cause distortion of the ball and a considerable loss of hardness. For light load applications, the ball can be attached with an adhesive such as epoxy. When adhesive bonding is used, an area on the ball should be roughed up by etching or abrasive blasting.