It is used for parts hanger. I was looking for small things. It is inexpensive and can be obtained and saved. There is no wastefulness to obtain the necessary number of one selling, but I think that it is easy to purchase if there are small bags that bring together a certain amount.
Particularly small diameter eye bolts are appreciated. Since the bolt part is shorter than the impression of the photograph, it becomes an obstacle with roller painting etc. It is regrettable that the dimensions are not written anywhere even though there is a reference image of each dimension.