I recently purchased a Heliopan step-up ring to enable mounting filters with a 67mm thread on a lens with a 40.5mm filter thread. It was quite expensive compared to the cheap Chinese stepping rings I normally buy (around 5-10x the cost). When it arrived I was surprised how heavy it was. In looking into this, apparently Heliopan stepping rings are made from Brass (apart from some very large ones), which is much heavier than the aluminium used by the majority of stepping ring manufacturers.
Brass filter threads are meant to be less susceptible to binding than aluminium threads. I have had filters / stepping rings get stuck several times in the past. But for me, it's not worth the extra cost of a brass stepping ring to avoid this relatively rare event, I'm not sure I'd even say it was a worthwhile trade-off for the increased weight. In the case of this particular stepping ring I purchased though, the Heliopan was the only one I could find.
