Yes I probably shouldn't have written that but in my experience I've straightened many steel bolts and screws where replacements were not available and had no issues. However going to a hardware shop and buying a similar screw made of the wrong material and not matching the specification is also a safety issue and a possible failure of the component. If you are doing everything to the maximum safety level you would only replace with the exact correct part not improvise a replacement and even that might not be sufficient if there is a flaw in the design. In that instance why are you even on a Dahon bicycle with a long history of recalls and safety problems and with a aluminium frame with a finite life and fatigue that always gets weaker with time. It's perfectly normal and expected for a aluminium frame to fail after years of use and most manuals give advice to maintain a watch for possible cracks that indicate this.

Anyway an interesting blog about Dahon's here although unfortunately the advice given only really helps those with steel Dahons. The comments in it reinforces my view that Dahon bikes are junk, unsafe and best avoided.

Bruce Teakle's Pages: Fixing a wobbly Dahon frame hinge