Material Analysis: Matched Pair of Antique Philippine Blades with Crystalline Matrix

[Oiluj13]

Hello everyone,
This is my first post on the forum—thanks for adding me! I am seeking your collective expertise to help identify a highly unique group of antique Philippine blades
My primary goal is to bring the unique composition and internal metal matrix of the matching twin pair into focus for the group.
Unlike standard acid etching or rust pitting, the steel on these two companion blades displays a dense, smooth, high-contrast micro-crystalline structure that is entirely flush with the surface plane. The pattern becomes intensely reactive and shows distinct optical chatoyancy under glancing, sideways light.
To help with the analysis, I have included a close-up image contrasting all three types of steel in my collection side-by-side: the granular crystalline matrix of the twin set, a heavily layered pattern-welded blade, and a standard carbon steel edge. I would deeply appreciate your insights on:
The Steel Matrix: What specific type of crucible or specialized lamination method is responsible for this smooth, granular, micro-carbide crystal segregation?

Thank you very much for your time, analysis, and guidance!

[Lee]

The 'patina' and rough finish could be obscuring something, but these appear to be tool grade and made with a 'modern' steel. I have a few Philippine pieces from the 1980s that they remind me of. Serviceable and fit for their intended function.

[Pendita65]

HI,

the first photo shows a Keris from Madura Indonesia it is laying diagonal over the other daggers. And the Ukiran (hilt) is faced the wrong way it should turned 180 degrees.

Regards, Martin

[Oiluj13]

Hi guys just wanted to show a close up of my blade. Has anyone else seen a close up of leaf steel like this?

[A. G. Maisey]

I believe that the perceived crystalline pattern that you can see is very likely the result of "cold forging", in reality the material is not cold when it is hammered, it has gone into the black heat range, and a bladesmith will sometimes continue his hammering into this heat range because it is believed --- & is possibly true --- that this "cold forging" will result in a higher degree of compacted material and a harder blade.

From experience I can say that if a mild steel, say below .5% carbon, has been used to make the blade, this "cold hammering" does work, because we do not draw a low carbon steel, we only quench at critical heat --- ie, where the material loses its magnetic properties.

If cold forging were to be used with a high carbon steel, this would really be counter intuitive & counter productive, because the correct heat treat cannot be improved upon.

[Ian]

Hello Oiluj13,

Welcome to the Forum and thank you for posing these questions.I would suggest that the two Luzon knives (which you call a "twin set") have been left to the elements and insect predation in the past. The damage to the horn hilts is usually caused by horn beetles. Both blades also show heavy oxidation, which makes any assessment of the underlying blade very difficult. While I can understand a desire to retain the age patina of a piece, the only thorough way to assess crystalline structure of the steel is to remove any oxidation and then etch the blade. This means polishing the blade back to white and etching it with an acidic solution.

It is hard to judge the age of the "twin set" but I think they are both 20th C and perhaps post-WWII. As such, they are likely made from monosteel and leaf springs are a common stock source.

The smaller dagger may be an Ilokano knife from northern or central Luzon. Again, it is too oxidized to assess IMHO. I would suggest that you also polish and etch that blade if you want to see its metallurgical features.

As noted, the obviously laminated blade is an Indonesian keris from Java.

Your three Filipino knives from Luzon need some care if you plan to keep them. Although some of the oxidation appears old and not particularly active, I would nevertheless suggest removing the rust (either mechanically or with an acid treatment) and oil the blades.

Regards, Ian.

[Oiluj13]

Hi Ian thank you for your suggestion and your Insite. The twins have been stabilized and treated with reannounce wax. What looks like pitting on those two blades is actually counterintuitive as they are almost completely smooth. if you run your finger across the flat of the blade it feels almost completely smooth i can however feel tiny bumps with my fingernail. I took your advice and conducted a window coffee etch and i will post side by side comparison on the bolo knife that i believe is leaf spring or scrap metal forged and the chopper of the twins i will attach copies of each as well as side by side pics for your consideration. Also, the handles of both are carved not damaged i will post pics of the handles as well as the damaged beetle eaten handle of the smaller knife side by side. I forgot to post pics of the sheaths that might help pin down when they were made. do you know anything about cyphers or marks on blades. both of the twins have the same type of mark like an m or a zig zag the chopper on the blade and the straight blade has it carved into both sides of the handle at the same spot Thanks again for your info.

[A. G. Maisey]

I'm seeing a POLL at the top of this page, I do not know what it relates to, but I'm guessing that it relates to taking a guess at what the metal used in the blade is:-


what type of metal
leaf spring
wootz
Pamor
Damascus
Just a rusty blade


totally impossible for me to determine from a photograph what ferric material has been used in these blades, but it does not appear to be a laminated blade, & thus not pamor nor mechanical damascus, it is unlikely to be wootz, it is probably modern 20th century steel, but it would need testing of one kind or another to determine exactly what kind of steel it is.

[Oiluj13]

Thank you for the perspective, Alan and Ian! I completely agree that casual guesswork from a wide-angle photograph has reached its absolute limit.That is precisely why I wanted to move past speculation and execute a localized material control experiment on my bench.As shown in this side-by-side close-up, I isolated a micro-window on both pieces, polished them to remove superficial patina, and etched them under identical conditions using a concentrated coffee solution .The results show two entirely different material reactions:The Top Window (Reference Bolo Control): Displays classic environmental pitting—deep, jagged, cratered black potholes that physically drop below the surface line, surrounded by a flat carbon steel background that dulled uniformly to a matte gray .The Bottom Window (Twin Blade Specimen): The surface remains completely flat, smooth, and structurally flush, lacking any of the jagged rust cavities of the bolo. Instead of a flat gray blackout, it separated cleanly into a dense, shimmering web of micro-crystalline networks that actively resist the acid.Does anyone else note this distinct difference in how the two steel matrices respond to the same organic etch? It seems to suggest we are looking at two completely different historical tiers of metallurgy hiding under the patina

[Tim Simmons]

Rough file marks I would say mean just an ordinary tool steel.

[Ian]

Tim, I think we could classify nearly all Filipino kn ives and swords as being made from "ordinary tool steel." Exotic alloys were rarely, if ever, used pre-WWII. Likewise stainless steel. Perhaps there are some examples of modern alloys from the last 50 years that were produced by a curious (and wealthy) smith. Traditionally, however, Filipino steel was fairly ordinary tool steel as you suggest. That was true for tools and weapons.

As far as grind and file marks on blades, this is the norm for the vast majority of tools and weapons produced up to the mid-20th C. Early pieces of gentry quality were often well finished, but commoners tended not to fuss very much about the grinding marks on blades.

Both of the longer Filipino knives have blade patterns that were used as weapons. The one with an acutely pointed blade may be Ilokano or Kapangan in manufacture but I don't know the name of that blade style (Xasterix is our local expert on blade forms and can likely inform us more fully). The one with the sheep's foot style blade looks like a ginunting variant, and that blade style is definitely used as a weapon.

As far as the spider-like pattern on the first of these blades, that is seen quite frequently when older (19th C and earlier), heavily patinated blades are sanded back such that the crystalline structure becomes apparent. My thought has been that the spider-like areas might have higher carbon content, but I have no evidence for that. I've made similar comments about other knives and swords posted here, but a quick search found no other example to cross-reference here. X-ray fluorescence could shed some light on the local mineral content.


P.S. The first post in this thread shows the spidery effect I was referring to in a mid-19th C barung blade. This is a laminated blade,

[A. G. Maisey]

Ian, I most sincerely doubt that Philippine smiths would ever use tool steel. I have absolutely no experience nor knowledge of the Phillipines nor of smiths working there at the present time, nor at any time in the past, but i do have extensive & intensive hands on knowledge of Javanese smiths, Balinese smiths & Australian smiths, as well as book knowledge of British forge work.

What I know is this:- smiths will use any steel that has a carbon content high enough to take & hold an edge after appropriate heat treatment. In the past carriage springs were favoured, when carriages disappeared, motor vehicle springs were used. In fact even low carbon steel can be used to produce a blade that is adequate for undemanding work, you just bring to critical & quench but do not draw. Worn out, damaged, broken tools like files & rasps often make very good blades, but of course these are too small to produce larger blades.

In recent years, smiths have sometimes used a tool steel for bespoke orders, my own preferred tool steel is 01, but I have made one hell of a lot of good serviceable blades from motor vehicle spring steel.

Tool steel is not cheap : motor vehicle springs cost nothing or next to nothing.

Working smiths in the places I know do not use expensive tool steel, especially for working blades such as have been shown in this thread. I doubt that Philippine smiths would either.

There is another thing too, & it is something that is not widely known. In times past, & through to the present day, in the rural areas of less than advanced societies, the people who actually used agricultural & other tools frequently preferred a blade made from low carbon steel, or from a high carbon steel that had been drawn to a lower hardness. The reason for this was that in the field & away from home or workshop, softer edges were easier to put a working edge on than were blades that had harder edges. This applied all through Jawa & Bali, it applied in Nepal and India, it applied in historic Britain. I don't know about present day factory made butchers knives, but up until about the 1960's, many butchers knives were drawn to a soft temper, back then butchers had a belt holster worn on one side that held several knives, and a sharpening steel worn on the other, they would use the steel in harmony with the blade, they would cut, then do a couple of passes on the steel,knives used in this way were always sharp. This method of work seems to have disappeared, the couple of working butchers I know now have multiple sets of knives, but they do not sharpen them themselves, they use them until the blades will not work satisfactorily, then they send them away to be sharpened.

[Oiluj13]

Thank you all for this incredible, high-level commentary! Ian, your insight on the underlying carbon distribution in these 19th-century matrices is spot on, and Alan, I completely agree that hard physical testing is the only way to move past 2D photographic guesswork.To answer your call for material validation, I have spent the afternoon coordinating logistics with an industrial engineering foundry right here in my local area.We have finalized an intake agreement for tomorrow morning. We will be utilizing their permanent laboratory spectrometer to run high-precision chemical weight-percentage readouts across the prepared bare-metal window of this specific piece.Using a stationary foundry machine will give us the exact mathematical data sheet we need to check the Manganese, Chromium, Vanadium, and Carbon levels .I look forward to posting the official certified foundry chemistry percentages here as soon as the machine runs tomorrow morning!

[A. G. Maisey]

Sounds good.

It is something I would never do, but this sort of testing is really the only way to get precise data --- if that is needed.

[Oiluj13]

Sorry guys this piece did not fit The exact machine used at the foundry was a permanent, laboratory-grade Bruker Spark Optical Emission Spectrometer (Spark OES) running Bruker’s official QMatrix evaluation software [𑀓I want to clarify why they were not run on this specific Bruker machine today.As Matt and the team at the foundry explained, their permanent laboratory spectrometer requires a completely flush, level, and flat metal interface to seal the argon-purged chamber perfectly [𑀓]. While my other piece fit beautifully on the stage, the unique hilt curvatures, geometry, and specialized fittings on these pieces simply would not allow them to fit flat against the machine's aperture stand.Please go check out my other post to see the certified laboratory printout and the complete results of that successful test!