This is a list of small bolt sources and information I maintain and try to keep current.
Please report any other information or broken links so I can update the list in the first post.
Thanks Dan
Canada
Newman Tools
Very small taps and die and info. both UNM metric instrument screws and the old series 0000-160, 000-120, 00-90 etc.
http://www.newmantools.com/taps/micro.htmFrance
L'Octant
Downloadable catalog (French) A good selection of metric small head bolts in brass, steel and stainless. Also a lot of other very handy stuff in the catalog. See page 137 for the scale bolts.
http://www.octantenligne.com/For English readers here is a brief list of materials.
Laiton = brass
Acier = steel
Acier INOX= stainless steel
Acier bruni = black steel
Germany
http://ghw-modellbau.de/German model engineer site small model hex bolts and very cool brass shapes
https://knupfer.info/shop/index.php/modellschrauben-alle-masse.htmlGerman source of metric model hex bolts .06mm - 4mm
A German source of small scale bolts.
http://www.modellbauschrauben.de/index.phpA nice source of small metric stainless hex nuts and bolts with small pattern hex size.
http://shop.autographmodel.com/screws-with-threadUnited Kingdom
B.S. 57 : 1957 -- Full BA thread standards
http://www.ba-bolts.co.uk/pdfs/BS%2057-1951%20-%20BA%20Screws%20&%20Nuts%20etc.pdf http://www.ekpsupplies.co.uk/UK model engineer site 0BA- 14BA hex bolts and small rivets in steel brass and copper.
http://www.ba-bolts.co.uk/smallhex.html BA hex bolts with one size smaller hex. 10 BA bolts have a 12 BA thread.
https://www.ba-bolts.co.uk/index.htmlThreaded rod steel, SS, brass, and phosphor bronze various sizes.
Small pattern UNC-UNF square nuts 0-80 to 10-32
http://hobby.uk.com/catalogsearch/result/index/?mode=list&q=coachbolts&x=0&y=0Small coachbolts 1.6mm to 3mm with square nuts.
http://www.pollymodelengineering.co.uk/Download catalog with a good selection of BA and metric small screws in brass and steel. The metric ones have rolled threads. Photo and data thanks to Peter Burnett.

1.6 Bolt A/F 2.43mm.
1.6 Rivet Head A/F 2.45mm.
1.6 Nut A/F 2.43mm.
1.4 Bolt A/F 1.96mm.
1.4 Nut A/F 1.96mm.
1.2 Bolt A/F 1.95mm.
1.2 Rivet Head A/F 1.96mm.
1.2 Nut A/F 1.97mm.
United States
https://jimorrisco.com/blog.aspA source of brass 2-56 to 0000-160 nuts and threaded rod, for those really small jobs. Also taps & dies and very good small nut drivers. Hex sizes for tools and nuts are model hex pattern.
http://www.microfasteners.com/A variety of types of fasteners not a lot of scale model hex available in small sizes. 00-90 & 0-80 taps and dies.
https://model-motorcars.myshopify.com/collections/small-parts-hardware/boltsSmall 0.5mm- 2.5mm and 00-90, 0-80 scale hex bolts, taps nuts and small rivets, clevises and carriage bolts. A bunch of other cool maybe useful stuff.
Model Motorcars and Scale Hardware.
https://godshallscustommachining.com/collections/frontpage?page=4https://godshallscustommachining.com/collections/frontpage?page=5Very good selection of 0-80 through 10-32 scale hex head bolts in brass steel and stainless. Also a nice selection of small hex and square stock to make custom bolts.
https://www.reactivemetals.com/mini-nuts-bolts00-90 and 0-80 scale hex head, cheese head and flat heat in brass with several finishes including black oxide. Good pricing on large orders.
http://www.minitaps.com/High quality micro taps and optical screws. The slotless 1.2mm and 1.16mm rimless repair screws make very good carrage bolts. The checkout does not work email or call so they can check stock.
http://www.rivetsonline.com/drive-screw/steel-drive-screws.htmlDrive screws steel and stainless 00 aqnd 0 screw sizes various lengths to make mini carrage bolts. Or attach small nameplates.
Cheers Dan