Forging a Heavy Signet Ring using the Rolling Mills

by David Cruickshank on 23/01/2010

From time to time I have to make a heavy signet ring. Perhaps for intaglio engraving or to set a stone on the top face.

I used to forge them using a raising hammer and a heavy planishing hammer on the anvil. This was a difficult process as, although you can work with black hot silver, the 6 mm square bar requires constant reheating and has a tendency to go diamond shaped and symmetry needs to be maintained.

I hate the thin ones available from wholesalers, just too insubstantial.

So to use the rolling mills I usually start with 6 mm square bar, I cut a length about 40 to 50 mm long. First I anneal and quench the bar, then I mark the central section all round with a permanent marker, 10 mm.

In my wire rollers I find the first pair of grooves that will grip the metal. I tighten the rollers enough to compress the metal but not enough to make rolling hard. I roll till the rollers touch the blackened area, then I reverse roll, rotate the bar a quarter turn or 90 deg. and roll the opposite corners up to the black, reverse and insert the opposite end of the bar and roll up to the black, reverse again, rotate bar 90 deg. and repeat rolling until you reach the black then reverse, change ends and do-se-do.

Tighten the rollers and repeat the whole process tightening the rollers after each set of four rollings. Take care not to  run on to the blackened area especially when you start, you will soon feel the bulge and know when to reverse roll. When the metal gets hard you can anneal and quench the whole piece. you will probably work through 3 or 4 grooves with many tightenings per groove. You can stop when the rolled or shank ends are reduced to about 2.5 mm square. The central section should be untouched.

Now you should have something that looks like a snake that has eaten an opossum!

Anneal the metal. Bend the shank metal in opposite directions on the same plane. So you have an S with a bulge. the bent ends can be held altrernately  during the next process, so you don’t cross roll the bulge on the wrong plane by mistake.

Move to the flat or sheet rollers now. Adjust the rollers to cross roll the bulge. Make sure that you cross roll the bulge at right angles to the tapered ends while holding on to one of the bent shank ends. Alternate the end you hold with each pass and tighten the rollers between each pass. The metal should flatten out equally on each side of a center line as you cross roll. Continue until the metal is about 3.5 to 4 mm thick by 8 mm to    12 mm wide tapering nicely into the shank ends.

You must decide with experience how broad and thick you want the central section to be and indeed the degree of taper you want, for example you can permanently mark the shank metal, decreasing the length of each pass. But make sure you main symmetry while doing this.

Anneal your piece.

Bend the central section on a grooved stump using a raising hammer and in a swage block. Then bend the shank ends with a mallet to form an overlapping circle.

I find a plumbers adjustable grips excellent for forming heavy rings. I choose a flat faced pair and grind the teeth off the jaws leaving a roughish surface on the jaws so there is some grip. The adjustable grips give you great leverage and control.

Make the rings somewhat smaller than the required size, cut through the overlapping shank ends and solder.

Some hammering needs to be done with a raising hammer, cross hammering to thin and further widen the top plate. Doing this limits lengthening the top plate. Generally hammer with mallet and hammers and file to achieve symmetry. Resize if necessary.

You may want to solder on a top plate or solder on a bezel to set a stone.

There are many other uses forging on the rolling mills can be put to.

Regressive rolling: where you mark a stopping point on a bar, you roll and reverse to / from that point. Rotate the bar 90 deg. roll and reverse as before. Tighten rollers. Mark a point slightly lower on the bar repeat. Re-mark, reverse roll as before, etc. One can achieve beautiful tapers for necklets  etc.

The same process can be done in the round on a draw bench pulling and reversing through a series of holes.

For the ring, perhaps try the process in copper so you under stand the process.

When you have you have finished the ring perhaps make a rubber so you can cast in future.

If all else fails carve a wax or go to ‘cad’.

David Cruickshank
I went to Sydney Australia in 1982 from London, previously from Aberdeen Scotland. Grays School of Art, Silversmithing and Graphic Design 1963 Since 1982 I have run a business in Terrigal supplying shops and galleries in the major cities of Australia. I produce several types of work: commissions for wedding and engagement rings, special pieces for shops. Then ranges of rings in gold and gold and titanium often layers of gold and titanium rivited together,the rivits being a feature. I have made series of pendants and brooches in silver, containing large semi- precious stones and 24 wearable pieces influenced by several visits to Morocco. I have a well equiped workshop, and am still working at 70.
David Cruickshank

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{ 5 comments… read them below or add one }

Tom williams February 8, 2015 at 9:24 am

This is a great read. Very well discribed. Have u every thought about making a video to go with the instructions? I’m very keen to give this ago but don’t have a lot of experience. I’m going to practice with silver but would love to watch a professional first.
Kind regards
Tom

Claudio Perez December 7, 2013 at 12:19 am

Una hermosa técnica, gracias por compartirla.
A beautiful art, thanks for sharing.

jason January 25, 2010 at 11:44 pm

I love rolling mill projects! You just gave me two or three ideas I’m going to have to try out now.

Thanks,
Jason

Cliff Manthey January 25, 2010 at 7:59 am

David,
Thank you for taking the time to write this blog.

Cliff

Michael Johnson January 24, 2010 at 10:35 pm

nice illustrations.
Thanks for sharing this.

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