Skin Radius Fix, from Chuggnut, is a compact script for 3ds Max that sets the inner and outer radius of a skin envelope to a fixed size. It's aimed at the repetitive task of adjusting envelope radii, which the script handles in one step rather than by hand.
The utility is designed to be easier than manual adjustment when you're working with a lot of bones. Instead of tweaking each envelope individually, the script applies a fixed radius, which keeps the process consistent across a rig.
Available in the ScriptSpot library, Skin Radius Fix is a focused tool rather than a broad rigging suite. If your skinning workflow involves many bones and you want a quicker way to standardise envelope sizes, this script covers that specific need. Full details and download are on the developer's page.