The rolling and grinding processes produce different surface finishes.
A rough surface finish is problematic in ball screw assemblies because it can result in higher friction and more wear on the load-carrying balls.
The grinding process produces a very smooth surface finish, and in theory, the rolling process does as well. But in reality, screws that are rolled must also be polished in order to remove an oxidation layer that forms during the rolling process. So when considering surface finish, the comparison is not between the ground surface and the rolled surface; it is actually between the ground surface and the polished surface of the rolled screw. The quality of the polishing step, and not the rolling process, determines the surface finish quality of a rolled screw.
Here below is our Capability of the ball screw parts:
Quality Certification: ISO9001:2008, TS 16949. 
Products: Ball screws in rolled or ground type, ball screw nuts, and linear guideways. 
Product range: Ø5 mm to Ø160 mm with different leads and different lengths 
Lead range: 01 to 50mm 
Length: 7m Max 
Material: GCr15, 40Cr, SUS303, SUS316, 9Cr18,or other tailored materials per your requirement. 
Accuracy Grade: C1, C3, C5, C7. 
Lead time: 3-8wks 
Advantages: High speed & mechanically efficiency, low noise, heavy load, long life time, low power consuming mechanism, low starting torque.