belt sequence and heat treating

D

deckerjm

Joined
Dec 3, 2012
Messages
13
what are your best recommendations for belt sequencing and where heat treating falls along that sequence?

I've gotten advice as simple as the following.

* 50-grit
<heat treat>
* 220-grit
* 400-grit
* finish (scotch brite, buffer, higher grit belts, and so forth)


I've also gotten advice that involves more belts.

* 50-grit
* 120-grit
<heat treat>
* 220-grit
* 320-grit
* 400-grit
* finish (scotch brite, buffer, higher grit belts, and so forth)

I hear that heat treating can fall almost anywhere along the line (and have to be careful not to get the blade too hot after heat treat), but I'm trying to find where it makes the most sense with regard to finish and belt life.

Note: I'm using 440C, though this sequence might differ for other steels.

Thanks.
 
Who will be performing the heattreat?I only ask because it could matter,you should ask the heattreater what is the common finish grit for this steel.
Eddie
 
For me, depending on what finish I want to end up with, taking it higher prior to heat treat leaves me less work.

Its going to be a lot harder to get 50 grit scratches out of a hardened blade, then it will be 220.
 
I only do carbon steels at the moment, so I am not sure about stainless, but I would not heat treat at 50 grit, scratches that deep could be considered stress risers and cause cracks. I go to at least 120 grit and usually 220 grit before heat treat. 440c I would think you could go 220 or even 400 bit I am not sure.
 
I agree with rwn2000,50 grit scratch pattern could cause problems with cracking in quenching. If you are going with a high polish finish you will be better off going higher in grit before HT. If I am making a work knife with a acid stone wash finish I will go straight from 80 grit to a fresh medium scotchbrite belt then heat treat. After HT I will clean it up with a fresh Trizac A 45 belt , then acid stone wash. Then again I know makers that do 100% of their grinding after HT. Everyone has a different method that works best for them. I think you just have to play around with in the shop and see what works best for you.Have fun and make lots of knives.
 
Last edited:
when i do carbon steel blades i go to 120 grit HT then back at 80 for any decarb removal and work to 120 then i use gators A160 100 65 and lower depending on final finish
 
Hi all,

Thanks so much. Need all the help I can get as a newbie and I appreciate the expert opinions. I'm sure I'll have more questions soon. :)
 
Here is a conversion I got from Tru Grit

........ GRIT
A300 .....80
A160......120
A100.......180
A65.........240
A45.........400
A30.........600
A16........1200
A6 ........2000
 
I've only done a few this way, but I'm happy with it so far:

36 bluefire/blaze belt (profile & rough bevel)
80 bluefire/blaze belt (get bevel near to finished shape)
120 bluefire/blaze belt (bevel in final shape)
220 A/O belt (polish out large grit marks)
400 trizact belt

220 hand-sand to get any remaining grit marks (the grit marks from the grinder can be hard to see as they're all in the same direction)
400 hand-sand to make sure all the grit marks are gone

Heat-treat (with blade protected by foil or anti-scale)

220 hand-sand to remove any minor decarb
400 hand-sand
600 hand-sand
800 hand-sand (sanding only in draw strokes to leave a satin finish)

The hand-sanding stages are much quicker than they sound as most of the work is done on the belts.
 
Thanks again, for the grit conversion table and the additional advice on belt sequencing. Some of this stuff can me maddening for a newbie.
 
You must log in or register to reply here.
Back
Top