Steel+aluminum quill stem - reliability concerns?
First, I'm not sure if this is the best place to ask this, so feel free to send me on my way. But I figured you folks may have a knowledge of the materials and fabrication methods involved.
I have a quill stem on one of my bikes that is very tall and very short. I know that it looks strange, but I bought it on a whim to convert a vintage mtb frame (with a very long top tube) to use as a drop-bar all-rounder style bike.
The stem apparently uses steel for the tall insertable quill portion, with a forged aluminum head.
I'm not exactly sure how these two parts are mated, but I'm curious about the longevity of this and how it will hold up over the long term. Can anyone weigh in on how this was made and if I should be worried that the two parts may eventually break free?
I've been considering getting a custom steel LD-style stem made to approximate the dimensions of this stem, but if this will hold up for the long-term, I don't mind using it.
Here's a picture of the stem in question: