i made me some lockpicks out of those bristles from streetsweepers, can i, or is it even possible to heat treat them? i've done searching but they say to use a thermometer to check the temperature, and i got no pics to judge by the color of the metal. any suggestions

you have made a good choice in what steel you have chosen,,those bristles are a low grade high carbon tool steel,,,get a cup of motor oil,,a set of needle nose pliers and your crack torch,,,,,hold lock picks with needle nose pliers and heat them with the crack torch till they are dull red,, now immerse picks into cup of oil for 15secs,,,take out of oil and allow oil on picks to drip back into cup for 30secs,,,now repeat 3 times,,,you have now tempered the tool steel, you have decreased its ductility whilst increasing its tensile strength,,,they should be fine now,,so out you go to create mayhem