Magnetic Backing Plates

Magnetic Backing Plates – Quick-Change Magnetic Backing Plates for Flat Lap Grinding & Polishing Machines

Professional magnetic backing plates for flat lap grinding and polishing machines. The magnetic surface allows instant tool-free disc changes between grit stages — simply lift off the used disc and snap on the next grit without tools, adhesive, or downtime. Available in 6" to 24" diameters in standard and 1/2" arbor configurations, from $7.50 to $60.00. Compatible with all magnetic-backed diamond flat lap discs, smoothing pads, lapping film discs, and polishing pads.

🔥 Shop Magnetic Backing Plates – From $7.50

Available Sizes & Pricing

Size Standard 1/2" 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 — Which to Choose

Feature Magnetic Backing Plate PSA Backing Plate
Disc change speed Instant — lift off and snap on Peel & stick — slower
Best for Multi-grit workflows, frequent stage changes Fixed single-grit setups
Adhesive residue None Some residue on disc change
Cost Higher initial cost More economical
Disc compatibility Magnetic-backed discs only PSA-backed discs only

Compatible Magnetic Discs

Related Tools

Frequently Asked Questions

  • Q: How do magnetic backing plates work?
    A: Magnetic backing plates mount on your flat lap machine's platen and create a strong magnetic surface. Magnetic-backed diamond discs, smoothing pads, and polishing pads have a magnetic layer on their back that bonds instantly to the plate surface when placed on it — holding the disc firmly during grinding and polishing. To change discs, simply lift the disc off the magnetic surface and place the next grit disc on. No tools, no adhesive, no downtime.
  • Q: Standard vs 1/2" arbor — which configuration do I need?
    A: Standard plates mount flat on the machine platen surface without a center post. The 1/2" arbor configuration has a center hole for machines with a 1/2" center post or spindle. Check your flat lap machine's platen mounting system before ordering — most standard flat lap machines use the standard (no arbor) configuration.
  • Q: What size magnetic backing plate do I need?
    A: Match the backing plate diameter to your flat lap machine's platen size. Common sizes: 6"–8" for small bench-top flat lap machines, 10"–12" for mid-size production machines, 14"–18" for larger production flat lap systems, and 24" for large production polishing machines. Always verify your machine's platen diameter before ordering.
  • Q: Can I use any magnetic disc on a magnetic backing plate?
    A: Yes — any disc with a magnetic backing layer will attach to a magnetic backing plate of the same or larger diameter. Ensure the disc diameter matches or is slightly smaller than the backing plate diameter for proper coverage. Do not use PSA-backed discs on magnetic backing plates — they require PSA backing plates instead.
  • Q: How strong is the magnetic hold during grinding?
    A: The magnetic hold is strong enough to keep discs firmly in place during normal flat lap grinding and polishing operations. The magnetic bond increases with disc size — larger discs have more magnetic surface area for a stronger hold. For very aggressive grinding with heavy downward pressure, ensure the disc is fully seated on the magnetic surface before starting the machine.