Hartford Technologies has been a leading manufacturer of precision steel balls since 1931. Our precision steel balls are used in a variety of products ranging from valves, couplings, automotive components, medical devices, cosmetic dispensers, water dispensing, and many types of bearings. Because of the many different applications, precision steel balls are available in varying degrees of precision and types of steel.

The type of steel will typically determine the level of precision you can expect in a precision steel ball. Because of the grinding processes used to manufacture precision steel balls, the relative hardness of the particular steel has a direct relation to the precision one can expect. For example, precision steel balls manufactured from a low-carbon steel can only be case hardened therefore allowing the ball to flex, or compress, during the grinding process making precision finishing difficult. Case hardening typically effects only up to a 0.015" depth. Precision steel balls manufactured from 440 stainless steel material, which is thru-hardened, will not flex or compress and can therefore allow more precise finishing. For this reason, the higher the hardness, the better the ability to control the finished dimensions of the ball.

In some applications, the ability of precision steel balls to resist corrosion is more important than the precision of the finished dimension. For example, precision steel balls used in applications in the food processing industry will use a 316 stainless steel due to its resistance to the chloride environment it is exposed to. Precision steel balls of this material are also commonly used in ball valves which can be used in the control of flow of numerous types of chemicals.

Where strength is a requirement, precision steel balls made of chromium steel offer the highest degree of strength and because of its high hardness, Hrc 60-67, it can also offer the highest degree of precision. Precision steel balls made from chromium steel can maintain a sphericity (roundness) tolerance within five millionths of an inch.

When designing a product where one or more precision steel balls will be required, it is important to find a material that offers the appropriate balance of precision, strength, and corrosion resistance. Fortunately, Hartford Technologies can offer precision steel balls that will meet that need.