heat treating

[Barbarosa]

I am making a knife and at this point all cutting and grinding are done I have sanded the blade with an 80 grit then a 150 I plan to go up to an 800 or 1200 grit to get a nice polish ..at what point should I harden the blade?

 

[silver_pilate]

I usually take a blade up to 400 grit by hand before HT. It doesn't have to be perfect, but get all the big scratches out before HT, and you'll make your life easier. After heat treat, I make a quick pass under the grider if necessary at 600 grit or better before going back to 320 by hand and working my way up.

--nathan

 

[Barbarosa]

silver pilate thanks man this is my first knife so I'm tryin to get it right again thank you

you da man!

 

[silver_pilate]

No problem. Every maker has their own process, but spending a few minutes of sanding prior to hardening the steel pays off in the end for me.

Have fun making that first knife. I know you have learned and will learn a great deal. Heck, I still learn from every knife I make. Post up a picture when you're done!

--nathan

 

[raylaconico]

I grind to 50 grit then heat treat.

 

[Bigfattyt]

I can also say from my very very very very limited experience (tying to finish up my first), the higher grit finish before heat treating will be much easier if you are doing all the sanding by hand. I left a few tiny marks on the blade, and after heat treat, they are taking forever to remove by hand.

If you have machine sanders then it is not as big of a deal.

 

[SteelSlaver]

Part of it depends on how you do your HT. When I do a blade of something like 5160 or 1095, that is going to be taken to around 1500,, I get it to around a good 220 grit and HT then I grind of the HT crud and finish it off. I have been doing D2 lately and I finish each batch of knives a little better before HT because I wrap them in SS foil before I take them to 1850. They come out with no scrud and an interesting grey. Then I can hand sand or whatever from where I left off. If I wrapped the lower heat blades I would get the same results, Problem is they need to quench faster and the foil would solw that down to much and getting them out of the foil for quench would be too slow also.

 

[Dan Zawacki]

I like to take the blade a grit or two past what I have planned as my final finish before HT.

This lets me play with finish levels and be dead sure that when it's finished up nicely, all of the lines of the contour are right where I want them. doing this pre HT makes it MUCH easier to fix any small problems, as the steel is still good and soft, and can be removed fairly readily.

It also helps to cut down a little on the scale it forms during the HT as the finer the finish, the less surface area there is to take on O2.