I'm looking for some mandrel bushings for custom work, but I can't seem to find what I need for sale. I'm wondering if any of you have any idea where I might find what I'm looking for.

Essentially, I'm getting into completely custom pens, but the only mandrel bushings I can find are for specific kits. I've been forced to make one off custom bushings from softer materials like iron wood, and I'd like something more durable. I'm looking either foe a set in multiple steps in millimeters and fractions of an inch, with bores for mandrels in 5mm, 6mm, and 7mm.

I'm also trying to get a hold of some folks I know that do machining, but if there's a way to just buy them, I'm down with that.

Feel free to ask clarifying questions if my post doesn't make sense... I'm largely self taught, coming from a knife making background, so my terminology might not be standard.