That's an old wore-out milling bit/pick (a tooth) off of a milling machine. My first under-the-table paying job as a kid was crawling under the drum with a puller and a deadblow and replacing broke/wore out ones like yours, by the bucket. Literally - Vermeer teeth came 100 in a bucket.
I don't know if you meant Austin, TX - but here in the Texas Hill Country, we use milling machines to make grade / cut roadbeds through the limestone far more than we do to peel back/resurface the roads, haha.
There are a million different styles, the bits you use come down to what equipment your running, site material, metallurgical compositions, proprietary pullers, and proprietary retention rings/sleeves/bases... Of course they really try to make it to where ya have to buy their teeth.
If your oblivious to the whole thing, i've posted up some stock photos for you:
my son found this in Austin. Sorry about it being blurry but it's the only picture he sent. What is it
