Information on Ordering Balls and Rollers

Lets break the ordering process down into the four main categories of basic information we will need.

  1. Ball size
  2. Ball material
  3. Ball quality ( grade )
  4. Quantity of balls required

If modified balls are required, please include the blue print or a simple sketch.
Our unique pricing policy allows you to order any quantity required from one ball to thousands or millions. We manufacture the quantity you require when you need it, so that you will not have to maintain an expensive custom ball inventory. Currently, ( Jan., 2007 ) our lead time is about two weeks. You can also take advantage of larger quantity price breaks if you want to schedule for future stock to dock deliveries i.e. by date or so many per week or month etc.

The size of a ball can be specified in several ways. We can manufacture precision balls of almost any diameter. The size can be specified as the diameter or as the radius of the ball required. It can be specified in fractional inches, in decimal inches, in millimeters, or even by weight if that is the parameter that is required. The standard measuring machines used at Bal-tec have a measuring uncertainty of only 2 millionths of an inch (50 nanometers), so with all of the other variables involved the actual ball diameter uncertainty can be safely given to plus or minus 10 microinches. (See our paper "Measuring Ball Diameter Commercially" on this website)

Since we can manufacture balls of any workable material, you only need to identify the material and the required specification. It may be a pure metal, an alloy, or a non-metallic such as ceramic. We do not work on toxic materials such as lead. We have over 50 years experience working with and manufacturing balls. This includes everything from exotic metals such as gold, platinum, titanium, tantalum, niobium and alloys of standard tool steels, tungsten carbide, ceramic and plastic. Refer to the pull down menu below to see the most common and standard materials used in ball manufacturing.


The A.F.B.M.A. grade determines the quality or the tolerance for balls. This is how the physical properties are identified. Both the A.F.B.M.A. specification and the military standards, use grades to specify the important aspects of a ball. We can manufacture balls of any A.F.B.M.A. grade. The grade determines the size tolerance, the common size within a lot, the sphericity or roundness, and the surface or micro finish of the balls. These can all be found on our A.F.B.M.A. Grade Tolerance Chart. Please check our Vocabulary Section for a full description of these physical aspects.

Our sphericity or roundness measuring capabilities, for commercial balls, has an uncertainty of plus or minus one millionth of an inch. For state of the art research work we can go all the way down to two nanometers but the cost for this service is extreme.

Ball Certification Available

The next thing to consider when specifying the material is how much certification is required. You can refer to the pull down menu and select the certification type. A Certification of Conformance is provided with every order free of charge. We are certifying that we have met the requirements of your purchase order. We can provide traceable Dimensional inspection services for an additional cost. We can measure the absolute diameter of a ball with an uncertainty of 10 millionths of an inch, for a cost of $15.00 per ball in small lots. This cost will go down considerably in large quantity. Traceable roundness and or sphericity can be documented with an uncertainty of plus or minus one millionth of an inch. This cost is $25.00 per ball. The surface finish can also be documented for $15.00 per ball. Raw material certification includes the chemical and physical properties of the specific metal melt or material lot. We can even go further back to the mining and or the part of the world the constituents originated. A minimum charge of $20.00 will apply.

Heat-treat processing certification can be obtained if requested before your order is processed. You may only require the basic process data or you may require furnace charts and specific results of hardness or tensile testing. Standard Commercial ball manufacturing uses a lot batch heat-treating process. The balls may have to have special processing to meet your specific requirements. The cost for specific processing can be quoted to you upon request. We can provide you with an actual hardness test certification. The standard cost to measure samples is $35.00 per lot. There may be an additional charge for the balls destroyed during the testing, if the material is exotic or otherwise expensive. Some balls may require passivation, x-ray inspection, dye penetration or have other special treatments. If any special processing is required, we will provide this service and document the result with a processing certification. If a first article inspection is required, just let us know before the order is processed. The cost for this service will depend on the time required for the inspection and documentation. A source inspection of your ball order, in our facility, can be arranged by appointment and the cost will be billed for the actual metrology or other lab time required.

Ordering Large Diameter Balls

When ordering larger diameter custom made precision balls, the time of machining will directly affect the cost. On large or giant diameter balls you must consider the following processes and tolerances that can be achieved.

±.005" on roundness and size.
±.002" on roundness and size.
±.001" on roundness and size.
from .0001" to .000010" on roundness and or size as required.

If you require technical engineering assistance, it will be important to know what the ball is being used for, what special environmental constraints, that is, what chemical, physical or temperatures the ball may be exposed to. Information on where and how these large balls will be shipped will be required, so we can build safe shipping containers. An 800-pound sphere can present some serious shipping problems. In the next section we will cover the information that we will need to know for us to bid, modified balls, gage balls, cylindrical rollers, large diameter balls and giant diameter balls. There is a separate section of gage balls and ball plug gages.

Ordering Rollers

Rollers have some unique properties that must be identified. The information required on an order includes quantity, size, length and material. The standard roller bearing materials are chrome alloy steel, E52100, with a minimum hardness of 60 HRC or type 440c-hardened stainless steel at 58 HRC minimum.


  • What is the specific corner radius and tolerance required? The standard is de-burred with a slight radius.
  • What is the length tolerance? The standard is ±.005".
  • How hard do you want it to be? The standard is full hard and stress relieved, (see above).


  • Are the ends tapered, curved to a radius or just flat?
  • Do you require a squareness relationship between the outside diameter and the ends?
  • Must the ends be specifically parallel?

Standard Dimensional Tolerance for Straight Cylindrical Rollers

Ground rollers with machined ends:

Diameter Size -- ± 0.0002 inches.
Roundness -- 0.0001 inches.
Overall Length - plus or minus .005 inches.

Lapped rollers with ground ends:

Diameter Size -- plus or minus 0.0001 inches.
Roundness -- 0.00005 inches.
Overall Length - plus or minus .002 inches.

Minimum Order

Our minimum order is $20.00 and our invoice line item minimum is $7.50. See Terms and Conditions.


was the Anti-Friction Bearing Manufacturers Association, a defunct organization.
Allowable Ball Diameter Variation
is the largest variation in diameter found in any one ball from the sample lot inspected.
Allowable Deviation From Spherical Form
is the greatest radial distance in any radial plane between a sphere circumscribed around the ball surface and any point on the ball surface.
Allowable Lot Diameter Variation
is the difference between the mean diameter of the largest ball and that of the smallest ball in the lot.
Basic Diameter Tolerance
is the maximum allowable deviation in any ball mean diameter from the basic diameter ordered.
Surface Roughness
is all those irregularities, which form the surface relief but are not deviations of form or waviness. The measurement of this characteristic is to be made with equipment meeting the requirements of an in accordance with Standard ANSI B 46.1
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