Purchased for evaluation of durability of coating film. In this test (ball on disc friction wear test), spheres of φ 6 or φ 1/4 inch are often used, so it will be helpful if possible to be shipped on the same day (inventory) if possible. There is something I want immediately, and Monotaro who handles ceramic ball is very convenient · · ·.
Besides buying bearings, I decided that something lightweight is better to use for polishing parts, and I am going well so far. Hardness is also sufficient. I do not know the durability if I try to use it a bit more.
It is different from usual way of using the bearings, but I used it for a folding knife bush (liner lock). It was a bad environment where friction was concentrated on one point and abrasion and rust easily occurred in steel balls. I am not worried anymore.