Setting Hoover & Strong Anniversary Bands

Channel setting anniversary bands appears complicated. However, carefully following this procedure will simplify the process and yield superior results. We urge you to know the millimeter size of the stones you intend to set before you order your ring. In doing so, you will be assured of a perfect fit, hence a beautiful ring. We recommend using a Leveridge Gauge or vernier caliper for accuracy of measurement. (illustration 1) After determining the millimeter size of your stones, refer to the diamond conversion chart. (Page 14). Many times the millimeter size of the diamond does not match the carat weight ordered. We suggest that you use the diamond size blank that your diamond measures in millimeters. All stones should the same size or at least .1 mm larger or smaller than the standard stone sizes. Greater differences in stone diameters will have a negative effect on the appearance of the ring and the setting process. An example of a great fit would be as follows; you have .12 ct diamonds that measure 3 mm each, which is actually the measurement for .10 ct diamonds. Order your ring to accommodate .10 diamonds since the drilling is measured for 3 mm stones. You will now create the “girdle to girdle” look that is desired in this type of ring.

Illustration 1 —A vernier caliper is used to determine the stone diameters.

When ordering, you need to know the style, finger size and how many diamonds you want the ring drilled for. If you have any questions, our inside order representatives will be happy to help you. To ensure quick and error free orders, please order rings in this sequence: Quantity — Karat — Color — Style — Qty of Stones. — Finger Size. The diamond size is included in the style name.

The depth to which the stones are set is dependent their diameter. If the stones are smaller than the standard, they must be set lower into the channel. If larger, then it recommended that you set them higher. Lay out the stones on top of the channel walls. Mark the walls at the point where the stones meet. This will help when cutting the bearings. Remember that they should not overlap or have more than .1 mm between them.

Using a 45° bearing cutter (hart burr) slightly smaller in diameter than the stone size, undercut one side of the channel wall. Carefully, tilt the burr upright to cut the opposite wall. Each of the bearings should be of the same depth and width as well as being level. Cut again with hart burr that is the same size as the stone. (Illustration 2A and 2B)

Illustration 2A — While holding the ring in a ring clamp, the seats are cut into the walls with a 45 degree hart burr.

Illustration 2B

When cutting is complete, seat the stones into the bearing to check the fit. Be careful not to force the stone in as this may damage it. Make sure that the spacing is equal and that the depth is consistent. (Illustration 3) When you are satisfied with the fit, secure the stones by squeezing the walls with a pair of smooth jaw pliers. (Illustration 4) Move the straight cut vertical wall first. Carefully repeat this on the undercut wall.

Illustration 3 — The stones are placed into the seats to check the fit.

Illustration 4 — The stones are secured in the seats by moving the walls over them with pliers.

Illustration 5 — A hammer is used to move the wall over the stone girdle.

Move the metal over the stone girdle by tapping on both sides with a tapping punch (tapered to 1 1/2 – 1 mm diameter at the top). Place the ring on a steel mandrel and tap with a chasing hammer using steady quick strokes and light force. (Illustration 5) An electric or air hammer may also be used. Be very careful that you donʼt damage the stones or shift them off location. To finish the top of the walls, use a medium cut equaling file to remove any dents. Follow this procedure with #2 or #3 emery paper on an emery stick to remove any file marks. For a neat appearance, file along the inner rim of the wall with a 3 square or knife-edge needle file. Follow up with a knife-edge pumice wheel in a flex shaft to lightly touch up and smooth this area. Use emery paper to remove any waves in the sidewalls and finish off with #4/0 polishing paper.

When setting the open-end styles, taper the tops of the holes with a 45° hart burr to provide a firm resting place for the stones. Place the stones into the pre-cut seats that are included in this style and squeeze the walls over the stones.

Closed end channels present a more complex scenario. If the stones dimensions are not correct in this case, the channel will not be long enough to accommodate larger stones and they will overlap and possibly break. The ends of the channel need to be undercut so that the stones can be slid into place. The rest of the channel preparation is the same as the all around stone rings. The end stones are inserted first and the rest are placed into their seats ending with the middle stone. Itʼs impossible to get the final end stone into its seat if they are placed in sequence from one end to the other. The walls are squeezed in, however the ends that already cover the stone will not need any additional work.

Princess stones are set the same way with the seat pre-cut into the channel. However, the ends of the channel need to be prepared with an inverted cone burr. This burr is used to square off the corners of the channel and stone placement done from the ends to the middle. The ring can now be polished and cleaned.

Copyright 2002 Fred Klotz