Collection: Metal Backing Plates
Professional metal backing plates and precision mounting support systems for lapidary flat lap machines, horizontal grinders, and rotary polishing systems. Features heavy-duty magnetic quick-change backing plates (6" to 24") for instant tool-free disc changes without adhesives, and precision-ground metal upper thin plates with PSA (pressure-sensitive adhesive) backing (6" to 12") for rigid, flat disc stabilization on rotating machine platens. Perfectly compatible with diamond flat lap discs, resin smoothing pads, lapping film discs, and wool felt pads across all standard lapidary equipment.
Magnetic Backing Plates
| Diameter |
Arbor / Hole Configuration |
Price |
| 6" (150mm) |
Standard solid / 1/2" center arbor |
$7.50 |
| 8" (200mm) |
Standard solid / 1/2" center arbor |
$10.00 |
| 10" (250mm) |
Standard solid / 1/2" center arbor |
$15.00 |
| 12" (300mm) |
Standard solid / 1/2" center arbor |
$18.00 |
| 14" (350mm) |
Standard solid / 1/2" center arbor |
$22.00 |
| 16" (400mm) |
Standard solid / 1/2" center arbor |
$28.00 |
| 18" (450mm) |
Standard solid / 1/2" center arbor |
$45.00 |
| 24" (600mm) |
Standard solid / 1/2" center arbor |
$60.00 |
Metal Upper Thin Plates with PSA Backing
| Diameter |
Mounting Configuration |
Price |
| 6" (150mm) |
Standard solid / 1/2" center arbor |
$10.00 |
| 8" (200mm) |
Standard solid / 1/2" center arbor |
$12.00 |
| 10" (250mm) |
Standard solid |
$20.00 |
| 12" (300mm) |
Standard solid |
$25.00 |
Product Type & Selection Guide
| Plate Category |
Mounting Method |
Ideal Application |
| Magnetic Backing Plates |
Affixes to machine platen; magnetic disc attachment |
Rapid multi-grit transitions, cabochon smoothing, faceting prep |
| Metal Thin Plates (PSA) |
Industrial PSA adhesive bonds plate directly to platen |
Permanent single-grit stations, ultra-flat specimen lapping |
Compatible Lap Discs & Media
Related Accessories
Frequently Asked Questions
-
Q: What is the operational difference between magnetic backing plates and metal thin plates?
A: Magnetic backing plates stay mounted to your machine platen, creating a permanent magnetic base so you can swap magnetic-backed grinding and polishing discs in seconds with zero adhesive cleanup. Metal thin plates with PSA backing feature an adhesive back that adheres permanently to your aluminum or cast iron platen, creating an ultra-flat steel contact surface for stick-on abrasive discs.
-
Q: How do I choose between the "Standard" and "1/2-inch Arbor" configurations?
A: "Standard" plates are solid discs designed for flat lap machines where discs sit flush on a continuous master platen without center obstructions. The "1/2-inch Arbor" configuration features a precision 1/2" center hole to accommodate machines with a threaded center drive spindle or alignment pin.
-
Q: How do I match the plate size to my flat lap machine?
A: Always measure the outer diameter of your machine's master platen. Standard benchtop machines typically use 6" or 8" plates, mid-size slab laps use 10" or 12", and heavy production machines utilize 14", 18", or 24" plates. Backing plates should match the platen diameter exactly.
-
Q: Can magnetic backing plates be used with standard peel-and-stick (PSA) discs?
A: No. Magnetic plates only hold discs that contain a magnetic rubber or ferrous steel backing. If you are using PSA adhesive-backed sanding discs or lapping films, select our PSA backing plates or stick them directly to metal thin plates.
