The Mirka Basecut 6 in PSA P400 sanding disc, model 20-342-400, is a 6 inch adhesive-backed abrasive disc sold in a 100-pack. This is a sanding disc designed for fine surface sanding and finishing work where you want a controlled cut and a smoother surface before the next coating or polishing step. If you run a shop that goes through discs steadily, this pack size makes sense because you are buying for real work, not just a single project.

Mirka positions the Basecut line as an economical, high-efficiency paper abrasive. In practical terms, that means you are getting a disc meant to balance cost with usable life. The stated aggressive initial cut helps the disc get to work quickly when you first put it on the sander, while the long working lifespan matters when you are trying to keep disc changes from eating up time.

The P400 grit lands in the fine-sanding range, so this is not the disc you grab for heavy stock removal. It is the right kind of grit when the job has already moved past rough leveling and you are dialing in the surface. That makes it useful for sanding sequences where consistency matters from one disc to the next.

The 6 inch diameter fits common 6 inch sanding setups that use PSA mounting. PSA, or pressure sensitive adhesive, gives you a direct stick-on attachment method that stays flat against the sanding pad. For users who prefer a simple adhesive disc over hook and loop styles, that can mean solid pad contact and a clean, straightforward setup.

Because this is a paper sanding abrasive, it is aimed at general sanding applications where value and throughput matter. The main advantage here is not flashy design. It is the combination of a familiar 6 inch format, fine P400 grit, and bulk 100-disc packaging from a brand that is well known in abrasives. That is exactly the kind of product that earns a place in a cabinet because it gets used regularly.

Who is it for? Shops, finish work users, and serious DIYers who already know they need a steady supply of fine-grit PSA discs. If your sanding process calls for a 6 inch pressure sensitive adhesive disc and you want a practical pack size with dependable performance, the Mirka Basecut 6 in PSA P400 sanding disc is a sensible buy.

• What grit is this disc? This Mirka disc is P400 grit, which is intended for fine sanding and surface refinement.
• How many discs come in the pack? The package quantity is 100 discs.
• What size sander pad is this for? It is a 6 inch sanding disc and is intended for setups that use 6 inch PSA discs.
• What backing style does it use? It uses PSA, or pressure sensitive adhesive, backing.

Mirka Basecut 6 in PSA P400 Sanding Disc Keeps It Simple

This is the kind of abrasive you buy when you know exactly what your process needs: fine grit, adhesive backing, and enough discs in the box to keep moving.

• Who it's for: Shops and serious DIY users running 6 inch PSA sanding setups who need a steady supply of fine-grit discs.
• Why it stands out: The Basecut line focuses on practical value, with an aggressive initial cut and longer working life than bargain-bin paper discs.
• Worth knowing: This is a P400 finishing disc, not a heavy removal disc, so make sure it fits the sanding step you are actually on.