(Photo LK)

These blades help explain the manufacturing technique for Kunnemann micro-drills. Upon close examination, one can see that some edges have been unifacially worked, that is, crushed or scraped in one direction, to produce a straight edge. The blade is then driven down that edge. Many of these are too short, too long, too flat, too narrow, too thick, too thin, etc. to be used and they were rejected. Koldehoff had seen this in the Fingerhut micro-drill assemblage.
(Kinsella photo)

THE CHICKEN GIZZARD drills (Photo LK)
These are some of the most unusual drills from the site. They appear to be polished by being swallowed by birds and sitting in their craw for a while before being expelled. I met a woman from Central Missouri a few years ago who had butchered about 8,000 turkeys since she started working for a poultry producer and has retrieved 32 such arrowheads from their craws. It is interesting to note, that Perino had seen a small, well-built, brick building on the Kunnemann site that he thought was an old school house. When he was hunting the site it was a chicken house. (Perino personal communication 2001)
 

(Photo LK)

Here are some of the Kunnemann cores. Note that many are worked from both ends. When a platform was no longer viable the opposite end was removed creating a new platform for micro-blade and micro-drill removal. Notice that a few of the cores show the remnants of drill removals that were unsuccessful, that is, the drills only went half-way leaving the unifacial edge intact. These aborted removals help explain how these drills were manufactured.
(Photo Pete Bostrom)

Here's a pic of one of the cores from Kunneman.

Since two-sided drills are prone to breakage, most micro-drills have 3 or 4 sides.

(Photo Pete Bostrom)

The drills also show use wear after repeated use and need to be discarded or resharpened. (Photoby Pete Bostrom)

The life of a micro-drill is represented here. (Photo Pete Bostrom)

 The blade is driven from a core, shaped into a micro-drill, used, resharpened, snapped, and discarded. A shell bead is included to show the size of the holes being drilled.