Considering a reblade project

[fishface5]

And seeking input from the experts. I'm thinking of making a magnacut reblade in a different shape for my BM 940. I'll be sending it out for heat treat and I'm primarily concerned with how that affects the grinding and drilling beforehand, but certainly interested in any other advice or words of caution. My tentative plan is to get stock in the oem thickness, then:

First:
- Drill the pivot hole, and shape the tang and axis lock interfaces (but do I need to leave some extra metal for any of these, for fine-tuning post heat treat?)
- Shape the blade, then assemble it with the handle to confirm fit/function/lockup

Second:
- Add opening thumb-oval, similar to the BM taggedout.r
- Grind the bevel (leaving about .10" at the edge?)
- Add jimping

Third: Send out for heat treat

Fourth: Complete grind, edge and finish work.

Any obvious booby traps in the above? Thanks for all input!

 

[Crag the Brewer]

I don't Have a 940, is it super thick? Leaving .100" bte?

do you mean .010"

 

[Pinoy Knife]

don't fit everything up till after heat treat..
rough size and shape is fine but reaming the pivot and fine tuning can not be accurate until after the heat treat.
a few thou here and there is all it takes to go from good to bad.. you will likely need carbide to ream it after H.T
i would rough grind (Oversize) the thickness.. Surface grind it after to exact as factory afterwards.
rough out the shape.. (undersize) the pivot hole by like 5 thou ..

 

[fishface5]

Thanks guys! In terms of shaping pre heat treat, is it safe to do maybe half of the bevel and plunge cuts on magnacut (finished thickness of oem blade is .114 so I will send it in for ht around .120).

Also, ideas on how to get it flat and parallel without a surface grinder?
Much appreciated.

 

[A.McPherson]

Also, ideas on how to get it flat and parallel without a surface grinder

Granite block, sandpaper, calipers and patience.

I know it kinda sounds like a smart@$$ answer, but seriously, flatten things as best you can on your grinder.

Take it to a granite block and use tape or glue or whatever to fasten a piece of sandpaper to it. Place your workpiece on it and use light, figure 8 motions to get it as flat as possible.

Once it's flat, mark it with marker or dykem or something, that side is your reference surface.

Turn it over and sand the other side in the same way. Measure it all over and mark the high spots with marker.

Continue sanding, using slightly more pressure on the high spots. Continue. Make sure you only sand the non reference surface, or you'll be chasing low and high spots forever.

 

[deerrockknives]

Yeah probably best to do everything fit wise post heat treat. If it’s one thing in knife making (and life) I’ve learned is everything that can go wrong, will go wrong

 

[Fixall]

Thanks guys! In terms of shaping pre heat treat, is it safe to do maybe half of the bevel and plunge cuts on magnacut (finished thickness of oem blade is .114 so I will send it in for ht around .120).

Also, ideas on how to get it flat and parallel without a surface grinder?
Much appreciated.

I think that’s asking for trouble in my opinion. I’d shoot more for .125” - .13” thickness before heat treat. You’re bound to get some warping, and that extra margin can save you from scrapping the project (ask me how I know).

Also, I think you’re going to have to send it to someone with a surface grinder for the best fitment. I mean it’s definitely possible to get a perfect fit with a folding knife blade without a surface grinder…. But not for me. YMMV.

On the plus side, an Axis Lock is one of the easier lockups I’ve worked with.

You got this.