|
At Hartford, the manufacture of miniature balls (and balls of larger sizes
as well) is a combination of an exacting science, long experience, and the
most modern facilities for miniature balls production. Only the finest
grades of precision ball wire are used, selected and inspected to Hartford’s
high standards.
Miniature balls are those that are less than 1/8” (3 mm) in diameter.
Some of their key applications include instrumentation for calibration and
switching, microvalves, pumps, medical and dental equipment, optical
devices, ball screws, timepieces, metal detectors, disk drives, and pens.
Hartford miniature balls are manufactured from carbon steel, chrome steel
tungsten carbide, and several grades of stainless steel, including
TrimRite® stainless steel.
How Miniature Balls Are Made
Wire is first cut into slugs, and headed or cold formed into spherical blanks
on high-speed automatic machines. The spherical blank has excess material
on the ends called poles, and a strip around the middle called a band.
Flashing prepares the headed blank for rough grinding by rolling the blanks
between metal plates to remove the band and poles. This is the initial
stage in giving miniature balls their roundness.
 
Heat treating gives miniature balls a precise level of hardness and improves
wear properties. Furnaces are computer-controlled to assure that the
metallurgical characteristics of each lot of miniature balls meet specifications.
Each lot of miniature balls is certified for conformance to specifications.
Finish grinding with a fine grit grinding wheel brings the balls to final size.
 
To obtain higher levels of precision, miniature balls undergo a lapping
operation. The balls are run with cast iron plates in a slurry of oil and
diamond paste that removes a small amount of material. This operation
also gives miniature balls their mirror-like surface finish.
Barreling or cleaning is the final process before inspection.
This operation removes the lapping or grinding solutions from
the miniature balls, and exposes their reflective finish. Great care is
taken during this operation to preserve the finish of the miniature balls.
Miniature Balls:
Quality Assurance and Packaging
Precision metal balls from Harford are quality-processed using the
same stringent inspection criteria for diameter, sphericity (roundness)
surface finish and hardness as larger precision balls, and meet the
precision ball grades standards of ABMA Std-10, ISO3290, and DIN5401.
Packaging for miniature balls is done in standard pack quantities,
or to customer requirements such as weight or balls per bag. Hartford
can provide special packaging, including clean room vacuum packaging
for balls manufactured for medical, dental or photonics devices. Miniature
balls can also be packed in electrostatic bags to meet electrical discharge
requirements. For ease of assembly and inventory control, miniature balls
can also be packaged in individual and custom quantities.
Hartford Technologies is a world leader in the development, manufacture,
and testing of precision balls, including miniature balls. For greatest agility
in manufacturing and logistics, miniature balls can be manufactured in
Hartford’s US plant, or in our
China facility. And whether balls are made
in Shanghai China
or Connecticut US –
or both – all miniature balls
manufactured by Hartford are subject to identical quality protocols.
Put Hartford to work for your next application.
TrimRite is a registered trademark of CRS Holdings, Inc., a subsidiary of Carpenter Technology Corp. |
