Saturday, July 11, 2015

A Tiny Acorn Die

Shortly before the 4th of July weekend I was contacted by Fred who had visited the studio in the past.  He had a relative, Dave, from Minneapolis coming for a visit and was interested in learning a bit about blacksmithing.  We set up a date where we could spend the morning together working at the forge.

There really wasn’t time for a basic blacksmithing approach and they wanted to see how I did some things that may be somewhat different from other shops.  I spend a lot more time making and using dies that most smiths I know, so I set up this little project.

I found a tiny acorn on a porter bar which Scott had made some time back.  That would make the male [positive] form.

I picked two small mild steel scrap blocks and welded them with two more pieces of scrap flat bar to create the crude configuration seen in image 01.  To that I welded a porter bar for easy handling in the coal fire.

01 Holding two blanks in register

The plan was to get an even heat through both mild steel blocks, place them in the hydraulic forging press with the tiny acorn between them and smash the die blocks around the acorn form creating top and bottom half female die components as the sacrificial end flat bar connectors budged out and collapsed.

That worked perfectly and after cooling I cut away the sacrificial connectors to release the die halves.

02 Sacrificial connectors cut away.

I relieved the sharp edges of the cavities with a die grinder.

03 Sharp edges relieved.

         Next, I mated the  die cavities around the male positive and tack welded the blocks in register.

Tacked in register.

That allowed me to attach a simple flat bar loop spring to the dies and weld the bottom die to the saddle which fits the hydraulic press - figure 05.  The tacks are cut to release the positive form.  The opening is adjusted to receive, in this case, a 7/16” round rod.

Spring and saddle attached and tack welds released.

I tested the die and there was a slight backward translation shift of the top die so I used torch heat on the spring to move it slightly forward.

This die will be used as a preforming die to isolate the perfect mass needed to form perfect little acorn in another die made from tool steel and set up for use with the power hammer.  The multiple strikes of the power hammer planishes or coins the surface better resulting in a more detailed form.

We did a few other forging operations and Dave, who already had pretty good hammer control, was quickly able to get the hang of drawing out and using the edges of the anvil.  I think it was a useful morning for him whether he pursues it any further or not.

I’ll try to soon post some ideas about how, with more preparation time, made a somewhat better die pair.

No comments:

Post a Comment

I don't often check for blog comments, so the best way to contact me is directly: at or