The Original Yankee Screwdrivers only accept bits with a unique round slotted shank. There are 3 shank sizes: small (7/32" or 5.5mm), medium (9/32" or 7mm) and large (5/16" or 8mm).

This Hex Adapter Chuck will securely hold any standard hex 1/4" bit.

The shank of this Hex Adapter Chuck will fit into the original large (5/16" or 8.0mm) Yankee Chuck. Please make certain this is the size you need!

By using this Hex Adapter Chuck you will greatly expand the versatility of your existing Original Yankee Screwdriver.

View Traditional Woodworkers Entire Selection of Yankee Screwdrivers.