The SHCS used to tighten various parts of the lathe are great if you only need to do that once in a while. Now that I have a die holder, replacing those is the next project. Most implementations of the handles involves knurling but I find the t-bar style more effective, esp. when you have oily hands.
Some 8mm drill rod (silver steel), 1/8” shafting from surplus mechanical aircraft instruments and a 10-32 die result in these:
These are a joy to use, the T-bar gives very fine control over the torque you apply without requiring a lot of finger pressure. I can lock the cross slide, carriage stop and the 2 tail stock features easily without hunting for a hex key.