fire bluing screw heads
 

i have been trying to fire blue some screw heads, while i have had success with getting them very dark that is not my intention. I want to get that brilliant blue. i don't know if i am over heating them or perhaps i am not heating them enough. Any advice on the matter would be appreciated.

G'day mate.
Try heating them to a dull cherry red. When i say dull i mean only just red, need to hold them in the shade to see the red. Hope this helps you achieve the result. :D

Heat slowly to a beep blue, then quickly quench in oil. If you go past blue when heating, quench and start again..

Jim..........

You are getting them too hot. For that bright fire blue, polish to a mirror
finish, and heat carefully. You are only going a little past 500° F. It
comes on FAST if you are trying to use a torch.

Some toaster ovens will do it, or a good heat gun. I used to just toss the screws on top of a wood stove and stoke up the fire a bit. When
they get to the right color quench them quickly.

Color chart here: Blue Blade Steel spring - steel, hardened and tempered steel, annealed

Agree. Polish head, try holding the shank in a pair of needle nose, and heat the shank, watching the head- small parts heat REALLY fast. When you are ALMOST there, get ready to drop into a small cup of oil. Have used 30 W motor oil, linseed oil- but never tried olive oil (maybe for a Carcano? :rolleyes:)

You may want to consider wrapping your needle nose with a wet rag and let the wet rag act as a heat sink. The grip can get a little warm.

Harbor Freight has some long handled needle nose pliers that can help (and they are cheap enough that you can dispose of them after changing their temper)

i thank you for your reply someone said i should see a straw color and then wait for it to turn blue but it doesn't all it does is get red. i have also quenching in linseed oil as i am told it offers protective properties, i will try again and try to heat it slower if no luck i will buy some nitrate blue from brownells and do it that way

For knife blades I like peanut oil for quenching. It's very light and transfers heat quickly.

for flat springs I have polished them and then I put them on the burrner of the stove ( electric). when they hit the right colour I quench in a sutable oil.
Dont put the burrner on max just till you can reach the right temp.
F.K.