Drill Holder for Square Hole Boring

to use with square hole drills with 19mm shank:

https://de.aliexpress.com/item/4001133069234.html?spm=a2g0o.productlist.main.77.27f56a43b5ebTF&algo_pvid=3a227762-4888-4583-845a-f776f746185a&algo_exp_id=3a227762-4888-4583-845a-f776f746185a-38&pdp_ext_f=%7B%22order%22%3A%225%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21EUR%215.59%215.59%21%21%216.21%216.21%21%40210385db17449712915093968e42c0%2112000025418472471%21sea%21DE%216172012225%21X&curPageLogUid=D8If297isZjs&utparam-url=scene%3Asearch%7Cquery_from%3A

https://ae-pic-a1.aliexpress-media.com/kf/S31afb437c77b4d22ae656c1427ba4cd8S.jpg_220x220q75.jpg_.avif

20.09.24:

reduction ring to regular 43mm added.

27.01.25:

Closed version now is added for easier printing.

03.06.26:

Model is no longer available.