BL series is the a compact type of RBL series zinc alloy ball joints. The housing of made of the high-strength zinc alloy is connected in perpendicular to the shank, which is incorporated with a ball. With a grease pocket formed on the top and bottom of the spherical area, this model achieves high lubricity and high wear-resistance. A highly accurate bearing steel ball used in the spherical area is first encased in the housing by die cast molding, and then is specially welded with the shank. This unique process enables the mirror surface of the steel ball to be transferred or duplicated on the spherical surface inside the housing to ensure full contact between the ball and the socket. Equipped with a boot for protection against muddy water. Use of a boot with high trackability in the ball shank prevents muddy water from entering the spherical area even in a muddy atmosphere. Accordingly, those types equipped with boots are used also in outdoor applications and automobile parts under the chassis.
Material
Temperature Range
Zamak 5 is a very common alloy throughout the world due to its combination of strength, ductility and fluidity, and the most commonly zinc die casting alloy in Europe and USA. The 1% additional copper added to the alloy improves the alloys strength and hardness. R, Cu, Mg, Be and Ti as well as zinc as the base com- ponent. It is excellent in mechanical properties, seizure resistance and wear resistance.
| Al | Cu | Mg | Fe | Pb | Cd | Sn | Ni | Zn |
| 3.5-4.3 | 0.7-1.2 | 0.03-0.06 | ≤0.1 | ≤0.005 | ≤0.004 | ≤0.002 | balance |
| Mechanical properties | Metric | Imperial US/UK |
| Tensile strength | 275 to 345 MPa | 1.89 to 2.38 PSI |
| Tensile yield strength (0.2% offset) | 235 MPa | 1.62 PSI |
| Compressive strength | 539 to 686 MPa | 3.72 to 4.73 PSI |
| Compressive yield strength (0.2%) | 294 to 334 MPa | 2.03 to 2.3 PSI |
| Fatigue strength(Schenk bending test) | 100 to 150 MPa | 0.69 to 1.03 PSI |
| Impact strength | 65 J | 48 ft-lb |
| Elongation | 1 to 5 ％ | 1 to 5 ％ |
| Shear strength | 170 to 230 MPa | 1.17 to 1.58 PSI |
| Modulus of Elasticity | 84.5 GPa | 84500 KSI |
| Hardness | 80 to 110 HV | 80 to 110 HB |
| Physical properties | Metric | Imperial US/UK |
| Density | 6.8 g/cm³ | 0.24 lb/in³ |
| Melting point | 383°C | 722°F |
| Coefficient of Thermal Expansion | 27.4 μm/m-°C | 15.2 μin/in-°F |
| Thermal Conductivity | 109 W/mK | 62.9 Btu/(hr·ft·°F) |
| Electrical Resistivity | 6.54 μΩ-cm at 20 °C | 26 %IACS |
| Specific heat capacity | 419 J/(kg•k) | 100 Btu/(lb·°F) |
| Linear expansion ratio | 24×10-6 | 24×10-6 |
The wear resistance of the high-strength zinc alloy is superior to that of class-3 brass and class-3 bronze, almost equal to that of class- 2 phosphor bronze.
| Amsler wear-tester: | |
| Test piece rotation speed | 185 min⁻¹ |
| Load | 392 N |
| Lubricant | Dynamo oil |
The permissible tilt angles of zinc alooy ball joint models are indicated in the corresponding dimensional tables. If the permissible tilt angle is exceeded, it may cause serious damage to the housing or the boot. Be sure to use the Link Ball within its permissible tilt angle.
Zinc alloy ball joints can be used at a temperature range from -20°C to +80°C (-4°F ~ +176°F).
If zinc alloy ball joint will be used at temperature of +80°C or higher, or receives an impact at low temperature, it is necessary to consider the safety factor of the housing. Contact C&H in advance.
In an actual application, the zinc alloy ball joint has been used as a ball joint for transmission control of a truck at service temperature between -40℃ and +140℃(-40°F and +284°F).
