Magnetic Backing Plates

Professional magnetic backing plates for flat lap grinding, faceting, and polishing machines. The high-flux magnetic surface enables instant, tool-free disc changes between abrasive stages — simply lift off the active disc and snap on the subsequent grit without adhesives, mechanical clamps, or workflow interruptions. Available in 6" to 24" diameters in both flat platen standard and 1/2" center arbor configurations. Fully compatible with all magnetic-backed diamond flat lap discs, resin smoothing pads, diamond lapping films, and felt polishing pads.

Available Sizes and Pricing

Size Standard Flat Platen 1/2" Center Arbor
6" $7.50 $7.50
8" $10.00 $10.00
10" $15.00 —
12" $18.00 $18.00
14" $22.00 $22.00
16" $28.00 $28.00
18" $45.00 $45.00
24" $60.00 $60.00

Magnetic vs. PSA Backing — Technical Comparison

Feature Magnetic Backing Plate PSA (Peel-and-Stick) Plate
Disc Change Speed Instant — lift off and snap on in seconds Peel, clean residue, realign
Best Workflow Multi-stage grinding (e.g., 60 to 3000 grit) Dedicated single-grit production
Adhesive Residue Zero residue, completely clean changeover Adhesive buildup requires periodic cleaning
Long-Term Cost Lower long-term cost — plates last indefinitely Low initial plate investment
Disc Compatibility Magnetic-backed and steel-backed discs PSA adhesive-backed discs

Compatible Magnetic Discs

Related Tools

Frequently Asked Questions

  • Q: How do magnetic backing plates work on flat lap machines?
    A: The magnetic backing plate adheres or bolts directly onto your machine's master platen. Its high-coercivity magnetic face exerts uniform magnetic attraction across the entire bottom surface of magnetic-backed diamond laps, smoothing discs, and polishing pads. Discs stay perfectly flat and secure during wet grinding, and can be lifted off effortlessly to swap grits.
  • Q: What is the difference between standard and 1/2" arbor configurations?
    A: The standard configuration is a solid flat disc designed for machines where the disc rests directly on a flat master drive plate without a central protrusion. The 1/2" arbor configuration includes a precision 1/2" center hole to accommodate machines with a threaded spindle or center locator post.
  • Q: How do I select the right plate diameter?
    A: Backing plate diameter should match your flat lap machine's drive platen. Common sizes are 6" and 8" for cabbing and faceting flat laps; 10" and 12" for commercial lapidary stations; and 14", 16", 18", and 24" for industrial glass and stone finishing platens.
  • Q: Can I use PSA adhesive discs on a magnetic backing plate?
    A: No. Magnetic plates require discs that contain a ferrous or flexible magnetic layer. If you use adhesive-backed (PSA) sanding discs, use our dedicated aluminum or acrylic PSA Backing Plates instead.
  • Q: Is the magnetic hold strong enough to prevent slippage during heavy grinding?
    A: Yes. The large surface contact area creates strong shear and holding resistance, easily withstanding the lateral forces of rough lapidary grinding. Always ensure the plate surface is wiped free of coarse swarf before seating a disc for optimal contact.