[Tim Harris]

I use the equivalent of 5160 spring for my blades. My usual peining method is: anneal the last inch or so of the tang, cool slowly then - hammer time. It seems the heat factor is critical, as sometimes I get cracking in the metal I am peining down.

Recently, I heard of hot peining. I tried it and found it works as consistently as doing it cold. There is also the risk of damaging the grip.

I'm curious about how other makers do it. Any views?

Cheers

Tim Harris
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[Sean Flynt]

I'm not a blade smith, but in my very limited experience, a cold peen is viable as long as I work slowly and pay close attention to the edges of the peen. A tip-to-tang heat-treated Windlass dagger blade just about killed me, and I wound up with a couple of small cracks (some in the peen, too:D ). If I had to peen another dagger or knife blade, I'd certainly anneal the tang but I wouldn't go to the trouble of a hot peen. I'd just cold-peen slowly.

I cold-peened this Windlass Steelcrafts blade without any trouble at all. It seated neatly in the recess of the round nut and cleaned up seamlessly with file and sanding. No cracks. The point, again, is that I haven't yet seen a need for hot peening my very simple projects. If I were using Albion's construction methods, that'd be a different story.

[Tim Harris]

[Nathan Keysor]

I would compare it to raising a helmet bowl etc. As you hammer the metal it work hardens and thus becomes more brittle. The more you are moving it around the more times you need to re-anneal it to stop it from cracking.



Nathan

[Christian Fletcher]

From my experience with peening 5160 I've found that merely annealing it isn't very effective as it work hardens almost immediately. It's better to peen it while it's still red but this is a problem because of the small volume of metal being heated (the end of the tang) sitting right on top of a good sized heat sink (the pommel). You pretty much need to keep the torch on the tang end WHILE you're hammering it. Naturally this can heat the pommel enough to damage the grip, so it's best if the grip is assembled in two halves onto the tang after the pommel is peened on (and cooled off).

[Angus Trim]

As CF says, the chrome in 5160 makes this steel real prone to work harden. My experience with 5160 kind of means that cold peening is pretty problematic...........

I've only done a few, but I have been able to hot peen these without damaging the handle...........

[Tim Harris]

Nathan, Christian, Angus, thank you for your insights. I hadn't really taken work-hardening into account, even though I've been doing this for nearly ten years. It makes a lot of sense.

That issue aside, I've found the steel excellent for WMA use. It's not exactly 5160, but an Australian auto leaf-spring alloy - XK9258S. Quite similar as far as I can tell.

I'll give the grip after pommel method a try. It will be a bit harder on closed hilts, but I can see it giving a tighter result.

Tim

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[Peter Johnsson]

Tim,
with some types of hilts you´ll find it is better peen the pommel after you´ve slipped on the components of a complete grip (that is: no sandwich construction of the grip). Grips with wire wrapping and ferrules or turk head knots are made this way.
On these hilts the rivet shank protruding from the pommel is generally quite small and narrow. It also helps that you have a rivet block that creates a distance from the pommel itself.
This means you can use a small oxy-acetlylene flame without too much heat bleeding into the pommel, or risking damaging the grip.

In ancient times the material in the tang was normally of another nature than modern alloy steel. More like soft iron. This is more malleable and can therefore be peened cold without too much trouble.
Regardless if you need to use heat to form the rivet head or if you can do it cold, you need to give it a proper shape.
To make peen rivets today look (and function) like those on ancient swords, we often need to resort to hot peening when modern alloy steels are used in the making.

When heat is used you need to make sure you do not leave the rivet head in a hardened and untempered state when you´re finished. This might otherwise lead to problems. Be sure to anneale the rivet head carefully after hot peening.
A great advantage wih hot peening is that you can form rivet heads of very sound size and shape. You can also shape the rivet head so it looks nice, like a small pyramid for exampe. A rivet like this is a witness to forging methods being used in the making of the sword, and thus looks good with many types of swords.

If you by some reason need to do a cold peening, it is important that the tang is properly annealed before you start. You need a steel that is soft and fine grained. Careful heat cycling is paramount.
If you are careful with the setting up and fitting before peening, you might get away with a minimum of deformation and still get a strong and dependable rivet head. Cold peeing is best reserved for small rivets or for peening that does not need a lot of deformation to set properly.

In some situations it can be a good idea to weld the tang halfway through the grip, changing to a more malleable material. This is normally frowned upon today as welded tangs have a bad reputation. Welded on tangs is a standard procedure on low quality "swords".
It does not have to be a mark of low quality however, if done properly.
In ancient times, tangs were often welded onto blades.
To do this you need to be sure the tang has healthy dimensions and that the weld is free from flaws.
When I weld tangs I normally do so before the forging fo the blade is complete, so that I get to forge over the weld and let it go through a few heat cycles, just to be sure the weld is sound and that the grain is fine. I weld the tang when I need to peen the tang cold, for some reason. In these cases I use a steel with low carbon content, but not plain mild steel for the welded on part of the tang. Mild steel might also work fine, depending on type of sword/hilt in question.

[Tim Harris]

Peter,

Thanks very much for the excellent information.

The problem seems to come down to work-hardening and correct annealing. Normally I heat the end of the tang to dark cherry and leave it to cool in the ash heap. Perhaps leaving it in hot/warm ash will give the right degree of annealing- unless of course I hot pein.

This all raises further questions, I'm afraid. Do you use harder material for the rivet block, or is it the same stock as the pommel?

.. and when you speak of possible problems arising from leaving the tang unannealed after peining it down, what would these be?

Cheers

Tim.
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[Peter Johnsson]

Hi Tim,

I do not use a harder material for the rivet block.
I use the equivalent of 1050 for hilt components in most cases.
In those rare situations I need a mild steel rivet shank/welded tang the pommel+rivet block are harder, but not to such a degree that it makes much difference.

In most other cases the protruding rivet shank/tang is of the equivalent of 6150 or 5160, that is a little bit harder than the 1050 pommel.

You focus the heating to the protruing rivet shank with a small flame. You also aim the hammer blows on the top of the rivet shank and try not to deform the rivet block too much. I srtike the rivet shank through the flame during much of the process.

Problems from hardening the peen is that if you leave it martensitic without tempering it, it might be brittle. Not a good thing. You want it tough. After finished riveting, anneale the rivet a few times. Avoid heating to critical, but rather slightly below and let it cool slowly.
It is a good practise to file the rivet peen after completion, both for the final touch ups, but also as a way to test any hardness.

[Tim Harris]

Thanks again Peter.

If I can't get consistently better results after applying your advice, I'm clearly doing something horribly wrong.

Cheers

Tim

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