Most Common Ball Materials
Ball Technical Data Sheet #1 — Metals Used to Manufacture Balls
| Metal |
Manufactured from |
Magnetism |
Machinability |
Hardness |
| Aluminum |
Aluminum Assoc. Spec. No. 2017, SAE No. 26 |
Non-magnetic |
Easily machined, drilled and tapped |
54-72 HRB |
| Brass |
Copper 60-70%, Zinc 30-40% |
Nearly non-magnetic |
Easily machined, drilled and tapped |
75-87 HRB |
| Chrome Steel |
Steel of the through hardening type AISI E-52100, The most commonly used ball material |
Strongly attracted by magnet |
Can be drilled by EDM and modified by grinding |
60-67 HRC |
| Hardened Stainless Steel |
Steel AISI type 440C |
Strongly attracted by magnet |
Can be drilled by EDM and modified by grinding |
58-65 HRC |
| Soft Mild Steel |
Steel AISI type 1018 |
Strongly attracted by magnet |
Easily drilled, machined, tapped, and welded |
28 HRC |
| Tungsten Carbide |
Tungsten Carbide 93.5 - 94.5%, Cobalt 5.5-6.5% |
Slightly magnetic |
This material is not easily machinable, use EDM or diamond grinding |
87.5 - 90.4 HRA |
| Unhardened Stainless Steel |
Steel AISI type 316 or 302 |
Only slightly magnetic |
May be machined, drilled and tapped |
30 HRC |
- Chrome Alloy Steel Balls,
- the most common bearing alloy, are manufactured from steel of
the hardening type AISI E-52100. The balls are heat treated
to a hardness of 62 HRC minimum. They are strongly
attracted by a magnet.
- Hardened Stainless Steel Balls
- are widely used in bearings and valves, and are
manufactured from steel AISI type 440C. Hardness is 58 HRC
minimum. They are strongly attracted by a magnet.
- Unhardened Stainless Steel Balls
- are manufactured from steel AISI Type 316 or 302. This
material is only slightly magnetic. It may be machined,
drilled, and tapped. It has the best corrosion resistance
of the standard metals. Hardness is about 30 HRC.
- Brass Balls
- are widely used in tooling and are manufactured from Copper 60-70%, Zinc
30-40%. They are easy to machine, drill, and tap. This
material is nearly nonmagnetic. Hardness is 80 HRB.
- Soft Mild Steel Balls
- are manufactured from steel, AISI type 1018. They are strongly
attracted by a magnet. Soft mild steel is easy to machine,
drill, and tap. The balls are highly polished for
decorative applications etc. Hardness 28 HRC.
- Aluminum Balls
- are manufactured from Aluminum Association Specification No. 2017 (SAE
No.26). The material is nonmagnetic. It is easy to machine,
drill, and tap.
- Tungsten Carbide Balls
- are manufactured from high grade material in the range of
Tungsten Carbide 93.5-94.5%, Cobalt 5.5-6.5%. The balls may
be ground with diamond wheels and shaped with electro
discharge machines. This is one of the hardest, toughest,
and most rigid materials available. It is slightly
magnetic.
See our web page, Ball Material Selection, for more information.
Ball Technical Data Sheet #2 — Plastics Used to Manufacture Balls
| Plastic |
Resistant to |
Physical Properties |
Maximum Usable Temperature |
Specific Gravity |
Water Absorption |
| Nylon |
Oils, greases, electrolytic corrosion and most organic solvents |
High Tensile strength, abrasion resistant, high
compression strength, low coefficient of expansion,
very good electrical properties |
360 °F. |
1.09 - 1.14 |
Is hygroscopic and absorbs considerable amounts of
water, .4 -1.5% |
| Polyethylene |
Bases, weak acids, and organic solvents ( except
chlorinated ones ) |
Attacked slowly by oxidizing acids |
175 ° F |
.90 - .91 |
low water absorption, low density, will float in
water, .02% |
| Polypropylene |
Bases, weak acids, and organic solvents about 80
°C |
Attacked slowly by oxidizing acids |
320° F |
.90 - .91 |
low water absorption, low density, will float in
water, .01% |
| PTFE |
Practically all organic solvents, strong caustics,
cryogenic missile fuels, liquid oxygen, and
concentrated acids |
Good physicals from cryogenic temperatures to over
500 °F, good compressive strength |
550 °F |
1.13 - 2.22 |
zero water absorption 0% < .01 % |
- Nylon Balls
- are resistant to most common organic solvents, oils, greases and
electrolytic corrosion. Nylon has a good heat resistance,
high tensile strength, fatigue endurance, compression and
shear strength, abrasion resistance, low coefficient to
friction and very good electrical properties.
- PTFE Balls
- are unaffected by practically all organic solvents, strong caustics,
cryogenic missile fuels, liquid oxygen and concentrated
acids. They have zero water absorption, while maintaining
the highest heat resistance of all thermoplastics. PTFE
has good physicals with cryogenic temperatures to +500
°F and good compressive strength.
Click to see our PTFE ball stock in our shopping cart.
- Polyethylene Balls
- are resistant to organic solvents, except chlorinated ones, and to bases
and weak acids. They have very low water absorption, and
they will float in water.
- Polypropylene Balls
- are resistant to organic solvents below about 80 °C, to
bases and weak acids. They are only slowly attacked by
oxidizing acids. They will float in water and have a low
water absorption.
See our web pages, Ball Material Selection.
for more information.
