Precision Ground Ballscrews

Accuracy grades

Grades are set by lead variation over any 300 mm of travel. Ground screws run C0 to C7.

• C0 3.5 µm / 300 mm — Jig borers, measuring machines, aviation
• C1 5 µm / 300 mm — Precision grinders and lathes
• C2 6 µm / 300 mm — High-accuracy machine centers
• C3 8 µm / 300 mm — Machine centers, milling, EDM
• C4 12 µm / 300 mm — Lathes, drilling machines, punching presses
• C5 18 µm / 300 mm — General CNC axes, drilling
• C6 23 µm / 300 mm — General industrial robots, single-purpose machines
• C7 50 µm / 300 mm — Transport and general machinery

Preload methods

Backlash is removed by an internal preload force; best preload stays below 5% of dynamic load C. Preload type codes: P compression · O offset.

• — Double nut + spacer (nut type D) — Tension preload, the precision standard
• O Offset-pitch single nut — Compact, high stiffness from a pitch offset
• — Oversized-ball single nut — Light preload, four-point ball contact

Optional functions

Appended to the nut code in the model number.

• E2 Self-lubrication — Lubricant reservoir extends service intervals
• R1 Rotating nut — Nut-driven axes; the screw stays still
• C1/C2 Cool type — Forced cooling against thermal growth
• Q1 Spacer — Spacer balls for smoother torque

Special executions

• M Stainless steel — Corrosion resistance
• H Hollow shaft — Coolant passage or weight reduction
• L Heavy load — Reinforced heavy-duty execution
• D Biaxial movement