X-Acto
#235 Razor Saw Blade

Medium
Walthers Part # 790-235, p. 871 Walthers 2012 HO Scale Reference
A scale, $3.79, currently in stock at Walthers

 
For delicate sawing, cutting circuit boards, model construction, shaping balsa wood, cutting fiberglass, plastic, narrow gauge tubing, metals, railroads tracks.