3M 7000120331 Abrasive Disc 400 Grit 8 Inch Wet Dry

Product Description

The 3M 7000120331 is a coated abrasive disc engineered for fine finishing on a wide range of substrates in both wet and dry conditions. Built around silicon carbide mineral on a C-weight waterproof paper backing, this 8-inch disc delivers fast, consistent material removal at 400 grit. It is designed for use with random orbital sanders and is suited for hand sanding applications as well. HVAC, automotive, and general trade professionals reach for this disc when a smooth, uniform finish on painted surfaces, primers, gel coats, metals, or wood is the goal.

This disc is used across residential and commercial finishing work wherever a fine abrasive cut is needed without leaving deep scratches. Common applications include scuff-sanding primer before topcoat, leveling gel coat on fiberglass, and finish-sanding bare or painted metal. The waterproof backing makes it equally effective when used with water or lubricant to reduce loading and extend disc life, or run completely dry for quick stock removal on softer substrates.

Key Features

• Silicon carbide mineral cuts faster than aluminum oxide and leaves a finer finish surface
• C-weight waterproof paper backing supports both wet and dry sanding without delamination
• Pressure-sensitive adhesive backing attaches directly to hook-and-loop or PSA random orbital sander pads
• 400-grit rating makes it suitable for finish sanding, scuff coats, and between-coat leveling
• Rated to 6000 RPM for safe use on standard orbital and disc sanders
• Compatible with water or sanding lubricant to reduce disc loading and extend cut life

Compatibility

Designed for use on paint, primer, gel coat, metal, and wood surfaces; fits random orbital sanders accepting 8-inch PSA abrasive discs.

Installation Notes

Secure the disc firmly to the sander pad before operation and confirm the tool RPM rating does not exceed 6000 RPM. Power down and unplug the sander before mounting or removing the disc. When sanding wet, ensure the work area and any nearby electrical equipment are properly protected from water exposure. Dispose of used discs per local waste guidelines, particularly when sanding lead-based paint or coatings.

Technical Specifications

• Disc Diameter: 8 inches
• Grit: 400
• Maximum Speed: 6000 RPM
• Abrasive Mineral: Silicon Carbide
• Backing Type: C-Weight Waterproof Paper
• Attachment Type: Pressure-Sensitive Adhesive (PSA)
• Application: Wet or Dry
• Weight: 0.02 pounds
• UPC: 00051144213399

Standard Information

• Brand: 3M
• Manufacturer Part Number: 7000120331