Grinding Media

Ceramic Balls

Ceramic Balls are mainly used in harsh environments. Their main advantages on steel is that they have a density 40% lower than steel, have 29% lower thermal expansion and are 150% harder. In certain high-speed applications their life is extended hundred times. It is also used as grinding media. 3 main types are-

Alumina Oxide - Ceramic Balls
Composition	99.5% Al2O3 / 0.5% other
Hardness	1700 Hv
Ultimate Tensile Strength	31,000 psi
Ultimate Compressive Strength	31,000 psi
Modulus of Elasticity	53 x106 psi
Maximum Working Temperature	1400oC
Corrosion Resistance	Inert except for hydruofluric, hydrochloric acid and hot concentrated sulphuric acids. Inert to most substances, not recommended for environments of strong alkaline solutions

Zirconia Oxide - Ceramic Balls
Composition	97% ZrO2 / 3% MgO
Hardness	80 - 84 Ra
Ultimate Tensile Strength	60,000 psi
Ultimate Compressive Strength	285,000 psi
Modulus of Elasticity	29 x106 psi
Maximum Working Temperature	2400oC
Corrosion Resistance	Inert to most substances, not recommended for environments of hydrochloric or strong alkaline solutions

Silicon Nitride - ceramic balls
Composition	87% Si3N4 / 13% other
Hardness	1400 - 1700 Hv
Ultimate Tensile Strength	/
Ultimate Compressive Strength	>570,000 psi
Modulus of Elasticity	44-45 x106 psi
Maximum Working Temperature	1000oC
Corrosion Resistance	Inert to most substances.

Chrome Steel Balls

Chrome Steel Balls are widely used in high speed ball bearings, valve industry, as well as, in a number of other industrial applications. Chrome steel balls have excellent surface quality, high hardness, high load bearing capacity and wear resistance, as a result of through hardening.

Chrome Steel Balls of 2mm OD,Hardness should be around 60HRC:

• China GCr15- P 0.03 % max.
• Hardness 60-66°HRC.
• Density 7.85 g/cm³

Applications:

• Ball Bearings.
• Valve Industry.
• Ball Screws.
• Automotive Industry.
• Machine Tools.
• Grinding Applications.

Stainless Steel Balls

Application:

• Grinding of solids and fluids.
• Liquids dispersion.
• Fine particle size reduction.
• Homogenization of fillers and raw materials.
• Attrition and pulverizing applications in ball, vibro, dyno, pearl, bead, pebble, attritor and small-media mills, vertical or horizontal.

Stainless steel balls and other shapes are used for grinding applications where absolutely no iron contamination is permissible, specially in food products:

Specification (stainless steel balls)	Hardness	Density
AISI 420	55/58 Hrc	7.75
AISI 440C	58/64 Hrc	7.75
AISI 302	25/39 Hrc	7.93
AISI 304(L)	25/39 Hrc	7.93
AISI 316(L)	25/39 Hrc	7.98
AISI 904	150/300 HV	8
AISI 430	135/380 HV	7.68