A question on Lauri PT blade

S

Spela

Joined
Mar 16, 2014
Messages
44
Hello
Is the discoloration that you can see in the picture normal on Lauri PT blades or is it an indicator of overheating by grinding?
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Best, Vito
 
Sometimes it means that only the blade was hardened. I bought some Scandinavian blades a few years back, Helle, Brusletto, Frosts, and Roselli, and the blades were hard, but the tang left soft enough to file or tap
 
They are purported to have a hard edge and a soft spine. I believe the colors are due to the tempering process that they use. Spine @ HRc 52, edge @ HRc 62.
 
aarongb and Bo T, thanks for replying. I also asked the same question on BritishBlades forum and the answers were very much alike as well. Good to know that the blade is allright :)
Best, Vito
 
What you see are the temper colors from when the tang was softened after HT. The blade is fine.

The tang was softened so the end can be peened, and so a hole can be drilled.
 
Pretty sure. A file will answer your concern.
1) Run the file along the hard edge. It should skate along with little or no biting.
2) Run the file along the spine. It should bite more and sound much lower in tone.
3) File a bit on the tang and the tang end. They should be as soft as the spine or softer. The file should bite quite well on the tang end.
 
On the other forum some one posted a video .The blade is induction hardened !!! The tapered section of the blade only is hardened .I had no idea anyone HT'd blades this way !
The tang wasn't softened 'cause it was never hardened !
'Fess up Spela !
 
mete said:
On the other forum some one posted a video .The blade is induction hardened !!! The tapered section of the blade only is hardened .I had no idea anyone HT'd blades this way !
The tang wasn't softened 'cause it was never hardened !
'Fess up Spela !
Click to expand...

The reported hardness along the spine is @ HRc of 52. Do they do a 2 step process; harden and temper the whole blade then induction harden the bevels?
 
Again, thank you everyone.
I also contacted the supplier, who contacted his supplier and both of them told me that the discoloration is completely normal, due to progressive tempering process.

Best, Vito
 
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