Folding Bikes - What size bolt fits the Q/R on a raleigh folder?

Hey-- all you Raliegh folding twenty owners out there: What size bolt (incl. thread count etc.) fits in place of the quick release on the down tube of the folding twenty? I would like to replace the q/r with a bolt for some street locking security here in NYC and for travel to foreign cities. It seems to be neither metric or english! Thanks!

Look again: It is a standard English UNC thread. I'm not rushing down to my Twenty to take it apart and measure the thread but I remember taking the original Raleigh QR in my pocket to Home Depot and picking a nice stainless steel socket head cap screw out of the bin with the same thread and enough length to file away a portion just like the original. Also reference Little Pixels photo collection. I think he has a pic of a modified bolt he made. Mine looks the same. Take care of it, you don't need our help. GR

Look here (http://bikeforums.net/showthread.php?t=150175&highlight=frame+bolt).

there are no 'quick releases' on a Raleigh 20

there are no 'quick releases' on a Raleigh 20
Erm - depends how you look at it. If you count 'easily loosened bolts with handles so you don't need tools' then there are three - the seat lowerer, the frame bolt and the handlebar loosen-so-they-can-turn-90° bolt. Jus sayin'... H ;)

Thanks for the replies and the excellent illustration Little Pixel. My Q/R (for lack of a better name) has, really, no "active" (threads in the "B" top part of your illustration) because of a washer-- but works fine with just the lower threads engaged.
Will seach the nuts and bolts bin here for the right bolt.

there are no 'quick releases' on a Raleigh 20How about a new term ? Folding facilitator.