Typical wire clothing hangers are either 11 ga. or 13 ga. wire. The heavier gauge wire may seem preferable but my experience has been that the breakage rate while winding the fork is very high (~100%). The 13 ga. wire clothing hanger does a good job for roasting marshmallows, however, it is not stiff enough for roasting hot dogs. The wire clothing hangers can be replaced by stainless steel wire. Below is an annotated list of wire I have used.
<> 10 ga. (0.102") Stainless Steel -- very stiff, easily handles multiple hotdogs, can be difficult to work with.
<> 11 ga. (0.102") steel clothing hanger -- high breakage rate (~100%)
<> 12 ga. (0.081") Stainless Steel -- good for marshmallows, satisfactory for one hotdog.
<> 13 ga. (0.081") steel clothing hanger -- good for marshmallows.
<> 14 ga. (0.064") Stainless Steel -- too flexible.
The stainless steel wire can be purchased from McMaster Carr
Hardwood dowels can be used as an alternative to broom handles. A 7/8"x48" hardwood dowel is a comfortable size and convenient length -- one dowel makes two handles. Also five 7/8" dowels fit within a 3" drain pipe if not heavily painted.
I typically store 10 marshmallow forks in a 4' section of 3" drain pipe. The forks are inserted face to face with the wire fork overlapping the handles.