Forged plunge line

D

deloid

Joined
Dec 19, 2007
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I've been practicing on making a clean forged plunge line (curved and soft edge). Since one side is always on the flat surface of the anvil I find it difficult to get them close enough in appearance.

I have several ideas for an easier approach. The most practical for me is to modify one of my ball peins to fit the hardie hole and strike on that surface.

What other approaches do you folks use?

I know I can grind that but I prefer a line from the hammer.

Thanks for any ideas-

Dean
 
Here is a shot of a bowie blade that Terry Vandeventer forged for a charity project we are working on together with the plunges forged in. I think he uses a cross peen. I'm not sure how he does it, but I do know he's good at it:D
9.jpg
 
John M Cohea said:
Here is a shot of a bowie blade that Terry Vandeventer forged for a charity project we are working on together with the plunges forged in. I think he uses a cross peen. I'm not sure how he does it, but I do know he's good at it:D
9.jpg
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I'll say he's good at it...I can't even grind them in that good! :eek::D -Matt-
 
Set the blade on the edge of the anvil ( a helper is really needed here) with the edge at the plunge line The froward step is the sharpest edge ,usually). Place a straight edge flatter or a piece of steel, at the opposing plunge. Strike, turn over and repeat. It should make a sharp and straight plunge on both sides.
Stacy
 
Or maybe you could make a spring fuller type setup that would give you an even parallel shoulder... I can get pretty close with a hammer but not THAT good. That's some impressive hammer control.
 
My peter wright has a nice sharp shoulder on the edge of the face above the cutting table, with a good square corner to the side edge of the face there. I use that corner a lot when forging the bevels up by the plunge. You can hold the blade in line with the horn, point to the right , anvil horn to the left, and get in there carefully trapping the steel between the flush edges of the side of your hammer flat face and the anvil face. I use my least crowned (finishing) hammer for this. The anvil horn can get in the way, but you can also hold the tang with flat tongs in a "T" style grip. Kinda what Mr. Apelt said only a one man operation, this way seems to make it less awkward for me.
 
The step on the anvil is the traditional way to do it. however I use a black smith's square flatter, or smoothing hammer to create my plunges. I use it like a punch. my son holds the blade on the anvil securly, I lay the flatter on the the blade where I want to start the the plunge and rap it with another hammer. I go right down the blade on both sides and it seems to work well.

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Jason
 
You could make or modify a spring fuller that could do both sides in one strike. I've been thinking about doing it for a long time, but never get around to it.

One of these days tough......Just like the 12,346 other projects I am planning to complete in my shop, when I find the time.
 
A smaller hammer... 1 to 1.5 pounds helps. It nees to be square, maybe slightly octogoned at the corners with nearly flat face. The face needs to run to the edge and the face-to-side transition cannot be largely rounded or under cut. You need to be able to see the part of the hammer that is moving the metal. The more time and care you take doing it, the better it will come out. Switch sides of the blade frequently as it helps in establishing, then maintaining eveness.

Mike
 
That's the tool ,Jason. As you pointed out, it takes a helper to position either the blade or the flatter, or to swing the hammer.

I usually just set the blade at the step and strike it carefully with a square faced, .5 kilogram hammer, that I ground the left side to a 90 degree edge. That usually sets the plunge good enough. Regardless of how good it is, it will have to be cleaned up later in finishing ,anyway.

As far as a spring fuller, it would have to be at the exact right angle to make a clean plunge. Fullering a tang or drawing a taper with a fuller is one thing (they will be refined later with the hammer), but trying to fuller a plunge (at an angle) with one stroke would require a setup that was for the blade you are doing only. I suppose you could make one that was adjustable with all sorts of set bolts and such, but why?
I have seen tapered press dies that are used to draw out the bevel do a clean plunge, though.

Stacy
 
bladsmth said:
That's the tool ,Jason. As you pointed out, it takes a helper to position either the blade or the flatter, or to swing the hammer.

I usually just set the blade at the step and strike it carefully with a square faced, .5 kilogram hammer, that I ground the left side to a 90 degree edge. That usually sets the plunge good enough. Regardless of how good it is, it will have to be cleaned up later in finishing ,anyway.

As far as a spring fuller, it would have to be at the exact right angle to make a clean plunge. Fullering a tang or drawing a taper with a fuller is one thing (they will be refined later with the hammer), but trying to fuller a plunge (at an angle) with one stroke would require a setup that was for the blade you are doing only. I suppose you could make one that was adjustable with all sorts of set bolts and such, but why?
I have seen tapered press dies that are used to draw out the bevel do a clean plunge, though.

Stacy
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Stacy, that's good info about using a smaller hammer with a squared up edge on it. I think I've got one around that would be perfect. Thanks :thumbup:
 
Will Leavitt said:
Stacy, that's good info about using a smaller hammer with a squared up edge on it. I think I've got one around that would be perfect. Thanks :thumbup:
Click to expand...

A person can make hammers to suit...

4140 is a good steel for hammers and it is a very common tool steel... comes in all shapes and can be found in large quantity as drops (cheap, if order minimums don't get in the way) at steel supply houses... where the machine shops, tool and die makers, mould makers shop steel.

4140, "cold rolled & annealed", grinds easily, and "flame hardens" easily.
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A guillotine can be used to do plunges. The moving swage needs to be loose enough side to side to create the angle. Make the moving swage short in height and/or the sides curved and it will have side to side play. Strike the moving swage at the edge to start the taper or establish the rough taper on the anvil and tidy it up in the guillotine.

A person could also make a hand or hardy-hole held sping fuller with one pivoting block. In use, heating the swage blocks a little will gain some forging time on the hot blade. 4140 would work... H13 would be absolute best (wicked red hard).

Mike
 
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I thought that's what you were referring to Stacy. mine's around a hundred years old. But definantly makes a nice bevel 3/4 up the blade in 2-3 trips down each side.
 
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