Adjustable Expanding Hand Reamers and Pilots
These have unfortunately been discontinued by the manufacturer
Adjustable Hand Reamers are versatile tools each capable of reaming a series of odd sized holes over a limited range of adjustment which goes from about 0.31 in (0.8 mm) in the smaller diameters up to around 0.593 in (15.0 mm) in the larger sizes.
Adjustment is easily done with two screwed collars which raise or lower the cutting blades by moving them along tapered seatings.