Hello. I manufacture a fishing alarm that is activated when 2 very small rods (each about ½ inch long and the diameter of a small paper clip) come into contact. The rods are perpendicular to each other and form an “X” shape. When the rods do touch to complete the circuit, the surface area of the physical contact is VERY small, being that the rods are round and only contact at the point at the center of the “X”. The amount of pressure to make the contact is also VERY small and can be accomplished with a feather. Because the contact point of the 2 perpendicular rods and pressure is so small I need to find the best combination of metals and plating that will allow the lowest possible electrical resistance, will stand up to light abrasion as the 2 rods as they rub against each other, and will also not corrode or oxidize easily. The circuit is powered by a 3 volt coin cell battery and runs at 5ma. Here are a few questions and any help would be greatly appreciated. Thanks in advance. 1. Does the base metal or plating metal determine the resistance of the rod? For example if rod is steel and plated with gold would the resistance of the rod be based on the plating material or the base material or a combination? If the answer is that the plating metal controls resistance would using a thicker layer of plating lower resistance even more? Would it matter if I added a layer of nickel between the steel and gold or multiple layers like nickel/gold/nickel/gold? 2. When a metal is rubbed against itself, are there other factors besides “hardness” that would determine how fast it wears? For example say I have 4 rods, 2 made of steel and 2 of copper and they are exactly the same size. If I put the 2 steel rods in contact with one another, and the 2 copper rods in contact with one another, and then spin the rods, with both sets having the exact same amount of pressure on each, will they both wear out evenly in the same amount of time or will the harder metal wear faster/slower? Are some metals better to withstand rubbing against itself? 3. I need the surface of my plated rods to be as smooth (less peaks and valleys) as possible because of the low physical pressure and small contact point. Are some base metals or plating metals better at allowing a smooth surface?