Steel ball is the key accessories of drawer slide telsescopes.
Carbon steel ball, Chrome steel ball, SS balls are the mainly materials for making slide balls.
No high precision need for drawer slide balls, G40 and G100 are good enought to adopt.
3mm, 5/32″(3.96mm),4mm,4.73mm,4.76mm,3/16″(4.763mm),6.35mm are the most popular sizes for making drawer slide.