Damascus Flaws: How To Spot Imperfections in Custom Knives

Learn how to spot flaws in Damascus steel blades, like delamination and inclusions, with expert tips from master bladesmiths.

They may be small and insignificant or obvious and glaring, but the skill that is involved in forging damascus steel and then fashioning blades and furniture that adorn custom knives like no other component naturally produces the potential for flaws in the steel itself.

Ironically, the structure of damascus steel, the allure of its beauty and texture, images and etched artistry, is brought together with the potential for a flaw. The production of billets that contain welded elements of 1080 carbon- and 15N20 nickel-alloy steels or other variations involves the marriage of metals. And like any union there is the possibility of a fault. The flaws may be serious or inconsequential. For the buyer, the ability to spot an imperfection and make a value judgment is highly beneficial in the ownership experience.

“I would say the most common flaw in a damascus blade is delamination,” ABS master smith Lin Rhea opined. “This shouldn’t be in a knife that is offered for sale. It’s usually evident as a hairline void in the layering and could occur anywhere on a blade. But I see them mostly in the deepest part of the blade as they are revealed in the bevel grinds. I believe this could be prevented by being sure the billet is up to proper welding heat before extracting it from the forge for the first weld in the particular stage of pattern development.”

In a similar perspective, ABS master smith Bill Burke sees imperfections as “a closed shut or incomplete weld that can be found anywhere on the blade. It can be seen as a dark or silvery line in lightly etched damascus or becomes a deep crevasse on heavily etched damascus—and it is caused by the smith not letting a billet soak at heat long enough before welding, or by manipulating a weld that has not been fully set and then working this tear back into the pattern.”

ABS master smith Steve Randall agrees and sees these types of imperfections and other potential flaws as well.

“The most common flaw on a damascus blade is the cold shut or an area where the pieces did not weld,” he observed. “It is not so much where it occurs on the blade such as the tip, edge or spine, but where the two different steels meet in the pattern. It’s the two steels that didn’t weld together that creates the flaw, and sometimes they aren’t noticed until [the maker starts] grinding into the blade.

“I would say another common flaw for damascus, mosaic specifically, would be shadow lines from the tiling process,” Steve continued. “Structurally they don’t change the steel, but they can detract from the mosaic visually.”

Both Rhea and Burke have encountered other flaws related to the fusion of the two steels in damascus.

“Less common is an inclusion of some kind,” Burke explained. “Twenty years ago flux inclusions were fairly common. Now one sees inclusions of weld filler material, though, overall, inclusions are less common now than 20 years ago. Inclusions are always found in between the elements that make up the pattern in a bar of damascus.”

Lin added, “I’ve also seen where the maker has left a bit of welding rod material within the damascus blade. This appears as a cloudy gray area and is pretty distinct in appearance from the hardened damascus. In the event wrought iron or mild steel is mixed with high carbon and the layering is of a relatively low number count, this could be part of the intended pattern, so it might be acceptable.”

According to ABS master smith/BLADE Magazine Cutlery Hall-of-Fame® member Steve Schwarzer, the particular combination of steels might raise the prospects for a flaw to develop, especially when the skills of the maker are evolving. He commented.

“The worst flaws are the delaminations and inclusions,” he said. “These might come from poor welding practices and the choice of alloys involved. Some welds are much easier to make than others and a higher level of skill may be required. Most of it is visual—bad welds are bad welds and don’t have the necessary molecular bond.”

For a potential buyer the ability to spot a flaw is an attribute that pays off when dollars are exchanged for the finished product. Although a flaw may have no impact on the structural integrity of the damascus steel itself, the degree of impairment—if any—ultimately lies with the potential buyer who assesses the level of discrepancy. Approaching a maker’s table, discussing the damascus, and taking a closer look at the blade will sometimes generate relevant conversation and exchange of information. Flaws can show up anywhere in damascus construction, so visual inspection comes with the territory.

Schwarzer advises buyers to check the knife thoroughly.

“Using magnification helps. If the blade doesn’t look right, it probably isn’t. A flaw may show up as a bright spot in a dark area, and some skilled people can reweld their billets. I do that regularly and especially when I do guards and stuff, taking a light hammer and welding heat to fix it, but not everything can be repaired. Sometimes there is no way to repair it, and that is one reason why I hardly ever sell damascus steel—[and if I do] only to skilled professionals.”

Visual Signs

When a buyer’s interest is piqued, the next steps involve courtesy and cordial exchange with the knifemaker.

“Flaws in damascus can range from very hard to see to blaring and obvious,” Burke remarked. “An experienced eye in good light and magnification are the best ways I know to detect them. Some can be felt, but feeling the blade and running your fingers up and down and across it are not reliable and can cause rust and tarnish. If you’re at a show and feel you want to look at the blade under a magnifier, then you should ask the maker if he minds. If he says ‘no’ or gets upset, then thank him and walk away.”

Randall concurs with that point of view.

“Bright light sure helps,” he observed. “It is difficult to find small flaws once a damascus blade has been etched. Running your fingers over the blade won’t tell you anything, and if you’re at a show I advise not doing it. Using a magnifying glass at the maker’s table could be awkward, and I would suggest respectfully asking before doing it.”

Historically, skilled makers and smiths have assessed their own work and identified flaws, correcting them or chalking up a flawed blade to the hazards of the craft. When ABS master smith Mike Quesenberry considers the flaw in context, he is frank in his response.

“The smith sees the weld lines with flaws before the steel is etched. To me that is something the smith has to deal with. I don’t have any problem scrapping a blade if [a flaw] shows up in the process. The hand sanding and grinding are where the time is really invested, and makers should be honest with their work. If you see a flaw, scrap it,” he stressed. “The best way to fix a flaw is to throw that blade away and start over again.”

Schwarzer smiles when he relates the style of an ancient practice.

“Japanese smiths worked out a way to hide a flaw if it didn’t mechanically affect the viability of the blade. They would do a nice little gold inlay. That was done in Persia, too, and a lot of other places. They would put artwork over something that was unseemly. If you have $300 in a blade and there is no mechanical problem, then that is a way to make it go away. It’s been said that the difference between a journeyman and a master smith is the size of the screw-up you can fix.”

Rhea acknowledges the human side of the situation. There may be a temptation to continue working on a knife with a flaw in the damascus, but then comes the realization on the part of the maker that causes him to refrain from that option. “When a buyer sees any odd discoloration in the form of surface treatment, color or texture, ask questions and give the maker the opportunity to explain or rethink his position,” he noted.

Resolving Situations

Bladesmiths and custom makers are genuinely committed to excellence. However, at times there may be a situation involving a flaw. When a purchaser detects something that may or may not be an imperfection, talking with the maker can resolve the situation to mutual satisfaction.

“If you buy a blade and then find a flaw, you should contact the maker and ask them about it,” Burke advised. “If it is something you cannot live with, ask for a refund or allow the maker to replace the flawed knife. In most cases, the maker is going to be unaware of the flaw. If the maker is aware of the flaw or refuses to do anything for you, then you either have to keep it and say, ‘Oh well’ or sell it to someone else with full disclosure of the flaw.”

“When I have a buyer who experiences issues of any kind, I would prefer that they contact me and give me the opportunity to evaluate, discuss and make it right,” Randall noted. “I’m sure most makers would not intentionally sell a knife knowing it had a flaw or without first pointing it out to the buyer.”

Rhea sees the interested parties taking the high road in almost every case. “Most makers will honestly make a sale with good intent and in good faith,” he reasoned. “If there’s a problem just contact the maker and let him or her explain or make it right. Ultimately his reputation is on the line and he deserves the chance to make it an overall pleasant experience.

“When it comes to flaws and issues,” Lin concluded, “we all have them and we handle them in our own ways. To the degree we act to prevent problems for the buyer we also prevent problems for ourselves as makers, as well as enhance our reputation. Leaving flaws in damascus will reflect on our honesty and our attitude toward the buyer. This is something to think about very seriously. So, will there be problems? Yes, but we should go to great effort to prevent them rather than having to correct things that might be perceived as an oversight. In the end, we are human and will want to use common courtesy and humility in our dealings.”

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