I think something worth mentioning, that not many realize/understand. There are few, if any heat treating standards out there for steels in the dimensions found in knife blades. For years I have seen many refer to various heat treating manuals as the "go to" source for "how to" heat treat blades. Early in my career, I tried to use common heat treat manuals as definitive sources for how to heat treat blades....and constantly had problems. That is until I noticed that ALL the heat treat manuals contain either a "foot note" somewhere in the first couple of pages, or a "post script" somewhere in the last couple of pages that states..... "All information contained in this manual are based on a 1" cross section of the specified material". What that means is a 1" x 1" x 1" cube of a given steel type. This got me to thinking..... does the size/shape make a difference? After years of experimenting, the answer is a resounding YES. Based on all of that experimenting, and subsequent testing I've had done, the general rule for heat treating blades steels that are commonly used when forging (the quenching portion) is that in order to achieve full hardness, the steel must cool from it's austinizing temp, to 400F or less, in 6 seconds or less.
The take away here is it use the information presented in heat treat manuals as a STARTING POINT. Not as an absolute.
Another detail that I've found many miss is..... whatever operation is being performed, the steel must be at a given temp WHEN the action takes place....... the best example I can offer is quenching. I have fielded many questions from folks who have troubles getting steel to harden. In many cases I have discovered that once a person gets a blade to temp, then remove it from the heat source, and "walk" to the quench tank.....meaning that the steel has cooled well below the austinizing temp before it hits the quenchant. If your quench tank is more than a "turn" away from your heat source, either move it closer to the heat source, or move the heat source closer to it. Sound simple, but you'd be surprised at how many never think about heating a blade to temp, then walk "across the shop" to quench it.
As a side note, for years I used only Vet Grade Mineral oil as a qenchant. While it may not have been "the best", it got me through both my ABS Journeyman Smith, and Mastersmith testing. Not long after achieving my Mastersmith rating, I started trying various commercial quench oils. Each had/has it's own unique characteristics..... some good, some not so much. In the end I decided to stick with Parks 50, and learned the "work arounds" for using it on steels that might do better in a different quenchant. Sure, I've wrecked a LOT of blades, but I've also gained a lot of valuable insight in the process. Whatever an individual chooses to use, understand that it's going to require that you put in some work, and wreck some blades before you get all figured out.....even then there's always more to learn. That's what I love about what we do.....every single day that I walk into the shop.... I learn something new!