Parker Fluid Steels
 

The following technical explanation may be boring or of no interest to some readers, if so just pass it by.

Questions often arise concerning the various fluid steels used by Parker; Vulcan, Parker Steel, Titanic, Acme and Jos. Whitworth. The questions seen here concern 1) whether one steel is "stronger" than another, and 2) whether there are any differences between them, some going so far as to conjecture that Parker merely called the same steel by different names for some kind of marketing ploy.

As to the strength issue, I know of no tests that have been done that demonstrates that one fluid steel ruptures at a different pressure than another or is more resistant to wear than another. We do know that Parker proofed all their barrels alike, Damascus and fluid, and all had to meet Parker standards, which standards were consistent with pressures that were later adopted by the Small Arms and Ammunition Manufacturers Institute ( SAAMI), and Parker increased proof pressures as SAAMI proof pressures increased. As to wear issues, previously published in this forum has been a Parker letter to an inquiring customer who was considering buying a C grade. As to the C steels, Parker ranked Acme, Bernard then Damascus in order of wear resistance.

Concerning the different fluid steels, we know that Parker procured them from different manufacturers, and lists of those providers have been published here. The alloy compositions were proprietary to the manufacturers and the precise alloys are not known, however, barrel steels fell within certain ranges of components and variations were slight. The barrels steels were purchased at different costs by Parker, and we have lists of how much they cost, starting at Vulcan and progressing to Whitworth. We sometimes hear of speculations that the fluid steels were all the same, but in my opinion, the procurement from different suppliers at different costs is inconsistent with the steels being the same. I know of no recent metallurgical analyses of the various steels.

There is additional evidence of difference. Barrel refinishers will tell you that the higher grade fluid steels will take a better, finer polish than the lower grades when using identical polishing techniques and grits. To me this demonstrates the finer grain structure of the higher grade steels.

To illustrate this point, I have attached several photos of two barrels, the top being a set of Parker Steel barrels from a P and the bottom a set of Titanics from a D. These were finished the same, and the difference in sheen, though subtle, is present. The difference is more pronounced between Vulcans and Acmes, but you can see it between even these PS and T steels. Of course this makes no difference to rupture or wear resistance, only to appearance.

Mr. Day this is a great subject. I could not imagine why anyone would not find it interesting. It would not be that hard to determine a chemical make up of the different steels and the grain structure. I could do it. The problem I am guessing would be in procuring all the steels from damaged barrels. It is not every day you run into barrels fit to destroy and who in there right mind would destroy a perfectly good set of barrels. I have been looking off and on for a set of Damascus barrels that are beyond repair for some research but to no avail so far.

eldon i hope you find some barrels to test some day...charlie

I find this fasinating. I would like to know if the different companys made their barrels to parker standadrs and compasison or wether parker bought barrels acording to the other companys standards and composition.

Several years ago I asked for samples in a Parker Pages article and procured a nice sampling. I sent these samples to two gentlemen for testing to no avail. I am working on getting the samples back from at least one of them. The samples that were sent out were Trojan Steel, Vulcan Steel both early production and late production, Titanic Steel both early and late,Acme Steel and Peerless Steel. This isn't over yet. Stay tuned.

Very interesting information that inquiring minds want to know. Thanks Bruce for bring to light a topic I have wondered about since I began an interest in Parkers.

Bruce, I have seen two coils of finished steel that had literally come from the same ladle possess quite different properties after processing, most noticeably the surface. I'm not going to bet on the chemistry, I will put my money on the process in which the steel was made as being the major difference. Great idea for a thread, but I have to wonder how it would be taken if the barrels all shared a basic chemistry of mild steel ???

Bruce, Great topic, I have often wondered if the different steels was just a marketing ploy, used by Parker to demand a higher price for the goods, would be great if some of thase steels could be put to the test, Gary

John, as I said, barrel steels fall within certain ranges of components and variations are slight. It may be the process , it may be the alloys that make the difference, I don't know.

As Dave mentioned, several attempts have been made to identify the differences. Remembering undergraduate metallurgy days, I think it is possible if a testing lab is available. However, there is a certain frustration in these efforts because several people have volunteered over the years to run tests, samples have been gathered and provided, and nothing has come of it.

Thanks Bruce. This is something I have wondered about as well. My theory is there is little or no difference between grades of Parker's fluid steel barrel composition. The designation Trojan, Vulcan, Titanic, etc. was a carry over during Parker Bros transition from damascus steel to fluid steel. Higher and finer grades of damascus are readily apparent and easily seen. A gun with a Plain Twist bbl wouldn't be expected to command the price of a gun with Bernard bbls. So when Parker Bros decided they would offer fluid steel bbls, Sales and Marketing types realized that from a value added standpoint it would be easier to justify the price of higher grade guns if they were fitted with what appeared to be higher grades of fluid steel. Customers just looking at the fluid steel bbls could see no difference between grades like they could with the damascus bbls. Even today we have to read the rib to know what the barrels were designated. So, that's my theory and I'm sticking to it: little to no difference in bbl composition. Fluid steel was simply a cost cutting measure over damascus steel and had to be justified. If someone did the actual research and testing and wrote it up I'm sure it would be published in Parker Pages as well as the DGJ. If, someone wants to send me samples and the PGCA agreed to pay for the tests there is a company near where I live that could lay the matter to rest.

Bruce and Mike, I have already procured a testing facility and they are awaiting the samples. That is the easy part. Now to just get the samples back. As I said before. Stay tuned...

I want to agree with Mike that the barrel steel is virtually the same but as Bruce stated there are definite differences in the way the barrels finish up and I am inclined to think that it may be the result of a higher chromium content in the higher grade barrels.

Bruce,

Thank you as once again you have brought up a subject that is not only interesting but thought provoking and educational. I have to admit I have never given a moment's thought about whether Parker Brothers used the same steel but named differently as a marketing ploy. My uninformed thought would be they used different compositions of steel for each grade of gun. I would think a metallurgist could melt the different steels and come up with differences in composition, possibly more manganese or carbon or whatever else is in barrel steel. I know Winchester made a big deal about using molybdenum in their barrels at one time. Possibly without advertising exactly what was in their steel each was constructed of similar but different ingredients for Parker barrels.

Dennis

Pretty crummy for 'gentlemen' to take sample then vanish.

Any scrapyard nowadays has a tester that can easily tell you what kind of metal you have. From what I gather, the testers have come a long way in recent times and produce some very specific results - not just steel or aluminum.

Greg, Both instances of these tests not getting done were the result of things completely out of the persons doing the test's control.

Bruce,Thank you again for bringing this topic up. It seems we revisit this every few years.

As most are well aware, there was a call on the DoubleGunBBS and PGCA sites in 2005 "Contribute Junk To Advance Barrel Strength Knowledge" with the hope of obtaining vintage barrel samples for composition and strength testing.

This was posted by ‘Zircon’ in Jan. 2007. Unfortunately, the testing effort apparently ended thereafter.

http://www.familyfriendsfirearms.com...p/t-55364.html


I am doing a failure analysis of a pair of Parker barrels - one set damascus, and the other set homogenous Vulcan “fluid steel”. These barrels were used in the study by Sherman Bell and Tom Armbrust, published in Double Gun Journal. They subjected each barrel to increasingly heavier loads and they both failed at about 30,000 psi. Modern ammo gets up perhaps to 12,000 psi. Most folks that shoot these old gals use shells loaded to the 7,500 psi range.

During the failure analysis I noticed that the fracture length for the Vulcan barrels was substantially longer than for the damascus barrels. A close examination of the fracture surface showed progressive, low cycle fatigue marks on the damascus barrel. The crack advanced slightly with each increasingly higher pressured load. On the Vulcan barrels, both sides failed by a brittle fracture mechanism. By this, I mean the barrels let go in one fell swoop. Even though both sets of barrels failed at 30,000 psi, the behavior of the damascus barrels was superior to the Vulcan barrels, owing to the fact that the Vulcan barrels failed in a brittle fracture mode. A ductile fracture trumps a brittle fracture every time.

One of the (myths) with damascus is that it will fail at the welds where the original rods were forge-welded together. When I looked at this particular set of damascus barrels using a metallographically prepared sample, and up to 1,000X optical magnification, I saw NO EVIDENCE of weld joint failure, slag in the weld joints, porosity in the weld joints, etc. I have about 30 old barrels in this study, homogenous, damascus, and twist included. I am a practicing metallurgist who holds an M.S. degree, and am qualified to state the observations of barrel integrity made in this posting.

On the two old Parker barrels, there is a screw hole that comes up from the bottom and pins the extractors in place. Both barrels failed at that hole, because it takes a (segment) out of the side of the chamber and is the thinnest portion of the chambered area.

The damascus barrel let go by a mechanism known as low cycle fatigue. Each succeeding round had higher and higher pressure. After several rounds, a crack started at the extractor screw hole. Each successive round caused the crack to open up just a bit further, until finally the overpressure could not be contained and the (barrel) failed in a ductile fashion. Ductile failures in steel look like a taffy pull at about 1500 to 3000X magnification using scanning electron microscopy. There is a cup and cone appearance with a lot of micro-voids present. This appearance is a dead-set giveaway to a ductile fracture.

The "fluid steel" barrel failed by brittle rupture. The fracture surface is more or less smooth, but has some "rivulets" in it that point back towards the initiation point, which again was the screw hole. The fracture surface was about 3X as long as for the damascus barrels. In other words, the same 30,000 psi final internal load created a lot more fracture surface in the homogenous barrel than in the damascus barrel. This indicates that, for an equivalent-length fracture, it took less energy to open up the homogeneous barrel than for the damascus barrel. The words in the Sherman Bell article were that the Vulcan barrel failed much more abruptly and (violently) than the damascus barrel.

So the verbal description of the failures during firing and the visual observations of the fracture surfaces are in accord with each other. Both barrels ripped lengthwise for some distance and then the rupture terminated in a circumferential crack. In the case of the damascus barrels the crack spiraled around with the weld pattern, but it was not on a weld, rather it was on one of the in-between areas. After the damascus pattern is formed by wrapping rods together and forging them into a strip (the "skelp") which is wrapped around a mandrel, spiral paper-tube fashion, and is forge welded together. These spiral welds remained tight and the parent metal is what failed. This may seem pretty amazing, but in many, many instances the actual steel welded structure is stronger than parent metal.

Many microphotographs, chemical analysis of the steel, etc. (will) make up the (anticipated) article. I'll also be looking at several other barrel ruptures and measuring the strength of the various barrel steels in the "hoop" direction as the barrel will always fail in hoop tension with a lengthwise crack. Any internally pressurized cylinder has 2X the force in the hoop direction as in the longitudinal (axial) dimension, so it's no wonder why barrels all seem to blow out with lengthwise cracks.


I've spoken to another gentleman who abandoned his testing effort related to illness 4-5 years ago, and have no knowledge of the fate of his barrel samples

Dr. Drew, This is one of the gentlemen that I sent samples to. I do have his micro photographs of the testing that he talks about. Very interesting material to say the least. Thank you for your reply.

This will be very interesting to see test results of composition. I believe we would still be shooting new damascus barreled guns today if they were cheaper to produce. It was never about safety or strength.

Dr. Drew,
That was fascinating and put into a vernacular that we all can understand. I must copy it and send to shooting buddies of mine who still step back when I'm shooting one of my damascus guns.

I have talked to "Zircon" several times on the subject as I was interested in trying to get out some elastic properties of the damascus. He informed me that for personal reasons he was unable to continue the work as he was attempting to find some properties in the hoop stress direction. We had some interesting conversions and although I have taken a couple of undergrad metallurgy classes I am not a metallurgist by any stretch of the imagination. As my studies focus on mechanics of materials, specifically composites, that is the research I would like to do on the damascus barrels. I have access to the necessary equipment to get out some tensile and compression data and even some higher strain rate properties. I bid on some 10 ga grade 2 damascus barrels today on ebay but lost. They were cut down to 21'' and I thought they would make a good specimen for research.

One more chime, some of the higher grades (and costly) may have very similar chemistry though the tolerances for each element will be held to a much tighter spec, that in turn compliments properties and consistency for the customer. What I suspect for example is a Vulcan steel barrel to have a wider range of Cr. (probably at the low end ) and Titanic to be held more at the spec # for its grade of steel. Probably the same grade of steel but the costly elements at the low range of the spec. The early 1900's also saw the open hearth overtake the Bessemer converter giving a much needed control to tighter chemistry in mass produced steel.

heres my two cents, fluid steel barrels are much cheaper to produce than Damascus. I dont belive it was ever about strength it was always about the money. Purdy is still not able to produce real Damascus