Jewelry Lapping and Polishing - Case Study

Many jewellery products are lapped and polished using Kemet Systems, the most common applications are when brass is used as the base material. This is often the case for belt buckles, pen clips, cuff links and identifying logos. Lapping and polishing using Kemet Lapping and Polishing Systems produces good cosmetic surfaces which are an excellent base for any subsequent gold plating operation.

Test Requirements: To produce a mirror finish on silver jewelry.
Component: Jewelry
Material: Silver
Machine Type: Kemet 15” diamond lapping/polishing machine

Jewelry Polishing Process Breakdown
Stage Plate/cloth type Abrasive type/grade Process time
Lapping Kemet Copper 6 micron type k std Diamond slurries 5 minutes Per side
Polishing ASFL Polishing pad 3 micron type k std Diamond slurries 5 minutes Per side

Lapping Jewelry

The faces of the parts are uneven and rough so require lapping to begin with. The parts are spaced evenly into the conditioning ring, then applying the faced pressure weight to ensure the parts stay in position. After the 5 minute cycle has ended the parts are turned over and the second faced lapped. The Pressure weight used was faced using an anti-slip membrane to hold the parts in place; a suitable fixture will need to be made. 1 ring was run with 3 parts for test purposes. A total of 3 rings can be run on this machine.

Note: because we are using a non slip film to hold the parts in position we have to clean the parts after each cycle as to ensure they don’t slip. This will not be required if a fixture is used.

Polishing Jewelry

Before polishing, we cleaned the parts free from all lapping residue to ensure no contamination. We cleaned the lapping residue from the copper lapping plate and applied the ASFL polishing cloth. Again using the non slip film faced weight to hold the parts, polish each side for 5 minutes. The parts were cleaned using Helit plus cleaning fluid in a Kemet 12 ultrasonic cleaner.

Test Requirements: To produce a mirror finish polish on Jewelry.
Component: Jewelry
Material: Silver
Machine Type: Kemet 15” diamond lapping/polishing machine
Lap Plate: ASFL polishing cloth
Abrasive Type/Grade: Kemet Diamond Slurries

Process Breakdown
Stage Plate/cloth type Abrasive type/grade Process time
1 Lap ASFL-Polishing cloth Kemet Liquid diamond 1 micron type k std 10-30 minutes Per side

Polishing Process for Jewelry

The Pressure weight used was faced using an anti-slip membrane to hold the parts in place; a suitable fixture can be easily made. The parts were grouped according to size, then placed into the conditioning ring with the faced pressure weight then applied.

Before Polishing Jewelry

Before Lapping Jewelry

After Polishing Jewelry

After Lapping Jewelry

Test Requirements: To produce a mirror finish
Component: Jewelry
Machine Type: Kemet 15” diamond lapping/polishing machine
Lap Plate: ASFL polishing cloth
Abrasive Type/Grade: Kemet Diamond Slurries

Process Breakdown
Stage Plate/cloth type Abrasive type/grade Process time
Jewelry Deburring 2000 grit polishing paper N/A N/A
Jewelry Polishing Felt Pad Kemet diamond slurry 1 Micron Type K standard. 5 Minutes

Polishing & Deburring of Jewelry

The parts were briefly rubbed on 2000 grit polishing paper to remove the burs. A suitable weight was then faced using a non stick membrane to hold the part in place. A suitable fixture or nest allowing you to polish multiple parts can be easily made. The parts were then polished on the felt pad for a cycle time of 5 minutes then cleaned and inspected.

Additional Info: The parts were cleaned using ultrasonics. Using a Kemet 30 with a 4% concentration of Helit plus cleaning fluid set at 55°C for 5 minutes, then rinsing in 100% deionized water for 3 minutes set at 40°C. Finally the parts were dried for 5 minutes set at a temperature of 65°C.

Before Polishing & Deburring of Jewelry

Before deburring Jewelry

After Polishing Jewelry

After polishing Jewelry