Gunmetal

Gunmetal alloys consist of the most commonly used bearing materials. They rank somewhat lower than unleaded or leaded copper tin alloys in load caring capacity. However they adequately satisfy requirements for bearings operating in the moderate loads and medium to high speed.

Lead has very low solubility in liquid copper. It is almost entirely insoluble in solid copper or its alloy. Furthermore lead melts at a relatively low temperature and when bearings are cast, the lead in the alloy freezes at last therefore forming irregular globules between boundaries of the copper tin alloys. The lead is to improve their bearing properties. The islands of free lead tends to smear over the bearing and shaft surfaces acting in effect like a built in lubricant. This can prevent seizing in the event of an interception in the lubricant supply. Therefore, these alloys are especially recommended for boundary lubricated and mixed film applications. Gunmetal alloys can be used against unhardened shafts.

• Reasonable strength
• Excellent Thermal Conductivity
• Reasonable corrosion resistance to sea water
• Max Operating Temperature 220℃