Corner slitting power hammer die set

[Spears]

I took a liking to a form of twist where the corners get slit and it kind of looks like little squares stacked up against each other. The only problem was I didn’t have a good way to slit the corners and I didn’t want to take the time with a hacksaw. So on my lunch hour I used a Bridgeport mill to make a small die set that could bolt right into my power hammer. This would spring open after each strike and allow me to increment along a square bar in just a couple of heats over a few inches slicing all the corners allowing me to achieve the desired twist.

The die was bouncing open too far allowing the spring to become “un-captured” so I installed a bracket on both sides to prevent that as you can see in the picture. After observing that it worked using it sloppy the first time I decided to use it skillfully and make a fire poker. Paying attention it worked fairly well so I tree bark textured the poker rod and I will probably end up making a set. Enjoy! Spears.

[Fosterob]

That is nice looking, what steel did you use to make your dieset? Hardened at all? You may be able to clamp a piece of thin sheet metal feeler on the back to locate the groove just completed to keep accurate spacings between grooves.
Rob

[ThomasPowers]

an ingenious solution to a common task!

Are you using a high alloy steel for the "cutters" like H13?

[Spears]

Used 4140 and left a web of .060 - .070 thick. Tapered the web like a blade with a dremel and die grinder but not “sharp sharp”. Fifteen minute soak time then Oil quench ~1600 – 1800 deg F. One plus one half hour temper at 350 deg F. Hope for Rockwell 50 + ? Limited equipment heat treat, but for other tools I’ve made zero problems.

Holding up well with its little bit of use. Under magnification no apparent wear or damage. The square bar has only a “point contact” before strike so it may not be taking on too much heat. It only breaks the corner as far or just shy of the inscribed circle so I’m hoping to get a few projects out of it. Full time should probably be made a bit better using jewelers files and material like H13. It looks like it will work real well for part time hobby/art. I definitely need to play with that idea for equal spacing. Thank you. Spears.