Plastic Balls
General Information
Plastic balls are manufactured from standard and speciality polymer resins in sizes from 3/32" (2.381mm) to 5" (127mm). Balls above 1" (25.4mm) are manufactured from extruded rod.
Plastic balls are a cost-effective substitute for metallic balls in low load bearings. They are also used as agitators in aerosol spray cans, lightweight check valves, medical diagnostics and a wide variety of other applications.
Tolerances to +/-0.0005" (+/-0.0125mm) are possible for certain materials such as nylon and acetal. Surfaces can be tailored from rough to highly polished finishes.
The following chart shows comparisons between the five main types.
Material Specifications
| Acetal (Delrin) | Polyamide (Nylon 66) | Polyethylene Low Density | Polyethylene High Density | PTFE | |
|---|---|---|---|---|---|
| Physical Properties | |||||
| Specific Gravity | 1.42 | 1.13-1.15 | 0.910-0.925 | 0.941-0.965 | 2.14-2.20 |
| Water absorption, 1/8" thick specimen, 24h saturation (%) | 0.25-0.40 | 1.0-1.3 | <0.01 | <0.01 | <0.01 |
| Dielectric strength, 1/8" thick specimen, short time (V/mil) | 500 (90ml) | 600b | 450-1000 | 450-500 | 480 |
|
|||||
| Mechanical Properties | |||||
| Tensile strength at break (psi) | - | 12.000b 11.000c | 600-2300 | 3100-5500 | 2000-5000 |
| Elongation at break (%) | 25-75 | 60b 300c | 90-800 | 20-130 | 200-400 |
| Tensile yield strength (psi) | 95000-12.000 | 8000b 6500c | 800-1200 | 3000-4000 | - |
| Compressive strength (rupture or yield) (psi) | 18.000@10% | 15.000b(yld.) | - | 2700-3600 | 1700 |
| Flexural strength (rupture or yield) (psi) | 14.000 | 17.000b 6100c | - | - | - |
| Tensile modulus (103 psi) | 520 | - | 14-38 | 60-180 | 58-80 |
| Compressive modulus (103 psi) | 670 | - | - | - | 60 |
| Flexural modulus(103 psi) | 380-430 | 420b 185c | 8-60 | 100-260 | 80 |
| lzod impact. Ft-lb/.in.of notch (1/8" thick specimen) | 1.3-2.3 | 0.8-1.0b 2.1c | No break | 0.5-20 | 3 |
| Hardness Rockwell/Shore | M94 | R120b M83b | D40-51 | D60-70 | D50-55 |
| Thermal properties | |||||
| Coef. of linear thermal expansion (106in./in/oC) | 100 | 80 | 100-2220 | 110-130 | - |
| Deflection temperature Flexural load oF @264psi | 255 | 167b | 90-105 | 110-130 | - |
| @66psi | 338 | 474b | 100-121 | 140-190 | 250 |
| Thermal conductivity 10-cal.-cm/sec-cm2-oC | 5.5 | 5.8 | 8 | 11-12 | 6.0 |
| Grade | Sphericity | Tolerance | Surface | ||
|---|---|---|---|---|---|
| Inches | mm | Inches | mm | ||
| 0* | 0.0005 | 0.0125 | +/-0.0005 | 0.0125 | Polished |
| I | 0.0005 | 0.0125 | +/-0.001 | 0.025 | Polished |
| II | 0.001 | 0.025 | +/-0.002 | 0.050 | Unpolished |
| III | 0.005 | 0.125 | +/-0.005 | 0.125 | Unpolished |
Design by logologo
Spheric Trafalgar Ltd
Wiston Business Park
London Road
Ashington
West Sussex
RH20 3DJ
Tel : +44 (0)1903 891200
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Spheric-Trafalgar (Thailand) Ltd
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Moo 4, Tambon Pluakdaeng
Amphur Pluakdaeng
Rayong 21140
Thailand
Tel : +66 (0)38 959 164
Fax : +66 (0)38 955 261
Spheric-Trafalgar Inc
9447 London Way
Suite 104
Rancho Cucamonga
California 91730
USA
Tel : +1 909 944 8424
Fax : +1 909 989 1957