One of the heat treaters I queried recently sent me the following and I'd be interested in comments. He obviously is knowledgable and I know he is a stickler for detail. The prices are Canadian dollars. One concern I have is that he contracts out the cryo. I read somewhere that the heat treat, cryo and temper should follow each other almost immediately.
"Hi Rob,
Thanks for responding to my post.
I know $20.00 bucks ($15.00, with 5 or more) sounds high for the heat
treating, but there is a few things to consider here. With the salt heat
treating one does not get any pitting, as with a atmospheric heat treat,
this means less time to finish the blade in the long run. Also there is
a minimal chance of warping and one can finish the blades to easily 600
grit, again it is easier to clean the blade when its in the un-hardened
stage.
100 % transformation of austerities and a controlled martemper with my
system is ensured. One does not rely on a secondary hardness cycle for
this. Blade performance increases dramatically with the martempering.
Few things to consider with the cryogenic treatment. Do your blades get
taken down to -310 F? Also do they get ramped down to temperature? If
the blades don't get cooled down 1 degree per minute to -310 F and also
warmed up to room temperature there will be thermal shock to the blades.
This shows up as stress cracks around grind lines and holes. In most
places one can not see them with the naked eyes? This can result in
blade that will develop cracks over time and then will eventually fail.
This is just some questions I would ask myself or your heat treater.
After all, your reputation goes out with every blade you make."
Any comments or other questions I should be asking are appreciated.
------------------
Rob Ridley
Ranger Original Handcrafted Knives
"Hi Rob,
Thanks for responding to my post.
I know $20.00 bucks ($15.00, with 5 or more) sounds high for the heat
treating, but there is a few things to consider here. With the salt heat
treating one does not get any pitting, as with a atmospheric heat treat,
this means less time to finish the blade in the long run. Also there is
a minimal chance of warping and one can finish the blades to easily 600
grit, again it is easier to clean the blade when its in the un-hardened
stage.
100 % transformation of austerities and a controlled martemper with my
system is ensured. One does not rely on a secondary hardness cycle for
this. Blade performance increases dramatically with the martempering.
Few things to consider with the cryogenic treatment. Do your blades get
taken down to -310 F? Also do they get ramped down to temperature? If
the blades don't get cooled down 1 degree per minute to -310 F and also
warmed up to room temperature there will be thermal shock to the blades.
This shows up as stress cracks around grind lines and holes. In most
places one can not see them with the naked eyes? This can result in
blade that will develop cracks over time and then will eventually fail.
This is just some questions I would ask myself or your heat treater.
After all, your reputation goes out with every blade you make."
Any comments or other questions I should be asking are appreciated.
------------------
Rob Ridley
Ranger Original Handcrafted Knives
