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Chrome Steel 52100

High Chrome Carbon steel, typically known as Chrome Steel, is a workhorse of the precision motion industry. It is the most common material in radial bearings, linear bearings, and ball screws. All Thomson’s standard products meet AMS-6440 at a minimum and are through-hardened to HRC 60-67 to achieve a fine surface finish and high load capacity. Single lot hardness typically is within two (2) points. Our Chrome 52100 balls ship with a preservative light oil. If you require dry product, please contact Customer Service. 

Stainless Steel 440C

Type 440C Stainless Steel has similar physical properties to Chrome Steel with a higher corrosion resistance to many common fluids. It is commonly used in specialty radial bearings, linear bearings, and ball screws as well as check-valves and plug balls. All Thomson’s standard products meet AMS-5630 at a minimum and are through-hardened to HRC 58-65 to achieve a fine surface finish and high load capacity. Single lot hardness typically is within two (2) points. All Stainless steel from Thomson is passivated.

Stainless Steel 430

Type 430 Stainless steel is an unheated treated, economical stainless material that provides corrosion resistance at low cost. Typical applications for this product include cosmetic mixing media, decorative trim, and light duty ball valves. For SS430, Grade 1000 is standard. All Stainless steel from Thomson is passivated.

Stainless Steel 302

Type 302 Stainless Steel is widely used in the food industry for its good corrosion resistance and economical costs. It is commonly known as 18-8 stainless. Its non-annealed hardness, created by cold working, is typically Rockwell “C” 25 to 39. Type 302 can be annealed to remove any cold worked magnetism and will result in a hardness of Rockwell “B” 75 to 90. For Type 302, Grade 100 is standard. All Stainless steel from Thomson is passivated.

Stainless Steel 316

Type 316 Stainless Steel is a more corrosion resistant version of the 300 series than 302, mainly due to the higher levels of Molybdenum and Nickel. Its non-annealed hardness, created by cold working, is typically Rockwell “C” 25 to 39. Type 302 can be annealed to remove any cold worked magnetism and will result in a hardness of Rockwell “B” 75 to 90. For Type 316, Grade 100 is standard. All Stainless steel from Thomson is passivated.

Stainless Steel 440A

Type 440A Stainless Steel has similar physical properties to 440C with a lower carbon level for workability. Thomson uses 440A for our Aerospace hollow balls. Our 440A hollow balls meet AMS-5630 and are heat treated for strength and through-hardened to HRC 52-60.

Brass

Brass balls provide excellent resistance to corrosion in water, is nonmagnetic, is an excellent electrical conductor, and is very machine-able. Its typical hardness is Rockwell “B” 75 to 87.

Silicon Nitride Ceramic

Silicon Nitride Balls are a popular choice among bearing designs and other high precision product applications. When compared to steel, this material offers a 60% reduction in weight, up to twice the material hardness, a coefficient of thermal expansion that is 70% less than steel, and a temperature operating range up to 1800° F (982° C). Silicon nitride balls are non-corrosive, anti-magnetic, and excel in low noise, high rigidity, and high load carrying applications. Thomson’s products are made to exceed ASTM F2094 Class II.

Letters indicating order of preference: A = Excellent, B = Good, C = Fair, D = Poor

Standard Ball Diameter is the value that is used for the purpose of general identification of a ball size (1/4”, 6mm, etc). Check out our “Quality Assurance” section to learn about measuring a ball.

Specific Diameter is the amount by which the lot mean diameter differs from the nominal diameter, accurate to the container marking increment for that grade. The specific diameter should be marked on the unit container

Thomson Precision Ball offers a full range of sizes from 0.011 inch to over 2.0 inches in diameter, in US standard and metric sizes. Our specialty is product as small as 1mm and up to 1/2 inch in diameter.

The ball grade is a specific combination of dimensional form and surface roughness tolerance. A ball grade is designated by a grade number. Thomson Precision Ball makes all of our standard products to exceed standard set by ISO 3290.

The specification defines the upper limits of the tolerances. The smaller the Grade number, the more precise the ball is. The chart below is a guidelines based on ISO 3290 and Thomson’s specifications. See our “Quality Assurance” section for additional details.

The Ball Gauge is the prescribed small amount by which the lot mean diameter should differ from nominal diameter, this amount being one of an established series of amounts. A ball gauge, in combination with the ball grade and nominal ball diameter, should be considered as the most exact ball size specification to be used by a customer for ordering purposes.

M05 = Nominal -.0005” (1/2” - .0005”)
P05 = Nominal +.0005”
P15 = Nominal +.0010”