Replacement frequency depends on the abrasive type, material being worked on, machine parameters, and production volume. Here's a general guideline across common product groups:

Abrasive Sheets & Discs: Replace when the cut rate drops or if loading/burning appears. In high-cycle operations, this could be every few hours to daily.
Abrasive Rolls (used in manual or hand-sanding stations): Replace sections once dull or clogged. Typical usage allows for 1–2 shifts, depending on pressure and surface area.
Wood Cutting Blades: Replace when the cut becomes slower, vibration increases, or diameter of wood cutting teeth is significantly reduced. In heavy-duty setups, this may happen daily or weekly.
Belts: Monitor for fraying edges or loss of aggression. Replace every few days in non-stop production or earlier if sanding efficiency drops.

CUMI abrasives are designed for extended life, reducing the frequency of changeovers.

Stearated paper-backed abrasives e.g., CUMI's stearated Paper with semi-open coat, are ideal - they prevent clogging, ensure smoother sanding, and avoid burn marks.

Typically 120 → 180 → 240 → 320 grit. Use stearated abrasives after 180 grit to avoid clogging during final passes.

Paper backing = smoother, fine sanding; cloth = flexible and tear-resistant; film = moisture resilient and long-life.

Over‑sanding is a pervasive issue in bodyshop work. It makes panels and filler areas thin which can lead to adhesion failure and visible defects after painting. 

Best practice:

• Always follow a structured grit progression (e.g., 80 → 120 → 240 → 320).
• Use guide coat or light dust markers to detect uneven areas early.
• Apply consistent, light pressure and let the abrasive do the work—avoid digging in.