1. Shape: round / square / rectangle

2. Round tool bit         size: 1/16''-1''             length: 4''  6''  8'' 

    Square tool bit        size: 1/8''-2''               length: 4''  6''  8''  12''

    Rectangle tool bit    size:1/8''-1''                length: 4''  6''  8''  12''   

3. Use in metal cutting