make - forge? - wedge for feathers-and-wedge rock-split

Hello all

Setting the scene:

"feathers" work well for splitting boulders so can be removed as
handleable rocks.
Lots of videos online eg. YouTube how to use them.

The ones I have:

http://www.weldsmith.co.uk/tech/minerals/pics/240314_feathers_holes.jpg

from page
http://www.weldsmith.co.uk/tech/minerals/240314_rocksplit/240314_rocksplit_drill_feathers.html
"Rock-split granite with "cordless" SDS drill and "feathers""

They work really well.
But these "10mm" feathers need a 14mm-dia socket.
The wedge is visibly oversized=overthickness for the feathers.
Saving just two mm of thickness would surely enable using a 12mm
socket.  Useful saving on drilling (14mm -> 12mm)
(/ (expt 12 2) (float (expt 14 2))) ;; 0.7346938775510204
73% of vol drilled - and the impact is concentrated on the smaller
cutting tip.


The question:

How would you go about producting wedges about 2mm to 3mm thinner than
the current ones?

Doing something to the current wedges would be okay.

Making them anew with something like forging could be a good project.
If so what steel would you use?  AISI1075? (C-Mn; 0.75%C).  If so -
"spring-temper"?

We have something called "silver steel" which is "(centreless-?) ground
0.8%C steel" (ie. right on the eutectoid).

Always appreciated the range of knowledge here.

Regards,
Rich Smith