A plain reading of the stated blade thickness figures on fixed-blade knife listings: what the number describes, how it relates to the other stated dimensions, and what the listing leaves unstated.
What the thickness line describes
Blade thickness is the short dimension through the blade, taken from one flat face to the other. It is a different dimension from blade length, which runs along the blade, and from blade width, which is the height across the blade. A listing that gives all three is giving three separate measurements, not three ways of saying the same thing.
On the (B26) 's Tactical Straight Fixed Blade Knife listing, blade thickness is stated as 3.9 mm, alongside a blade length of 15.5 cm and a blade width of 3.6 cm. On the Camping High Hardness Tactical Knife Fixed Blade Survival Knife listing, the short description gives blade thickness as 5 mm with a blade length of 9.8 cm. Read each as the listing's stated figure, not as a measurement you have checked.
The unit is the first thing to notice. Thickness is written in millimetres while length and width are usually written in centimetres, so read the unit attached to each line rather than carrying one over from another. Ordinary conversion is safe where the listing is consistent: 3.9 mm equals 0.39 cm, and 5 mm equals 0.5 cm. That changes how the figure is written, not what it measures.
What the figure does not pin down
A single thickness figure does not say where along the blade it was taken. It does not say whether it is a maximum at the spine, a reading at the thickest point, or a single point somewhere else. A blade that tapers toward the tip will not hold one thickness along its full length, so one number cannot describe every point on the blade.
The listings also do not explain how thickness relates to the stated blade width. Width and thickness are presented as distinct dimensions, and neither figure fills in the missing measurement points for the other. If the exact thickness at a particular point matters to your decision, ask the seller a question that produces a specific answer: at which point along the blade is the figure taken, and is it a maximum or a single reading? A reply that names the location and the surfaces resolves the point; a reply that only restates the number does not.
The Camping High Hardness Tactical Knife Fixed Blade Survival Knife listing is a useful example of a narrower set of facts. Its short description gives a length of 21 cm, a blade length of 9.8 cm, a handle length of 11 cm, a blade thickness of 5 mm and a weight of 355 g, but it does not state a blade width. So the thickness line there stands without a companion width figure, and the listing does not say which surfaces or points any of its dimensions were taken from.
Reading it alongside the rest of the listing
The thickness line sits among other stated facts, and none of them changes what the figure means. On the (B26) 's Tactical Straight Fixed Blade Knife listing those facts include a total length of 29.7 cm, a blade material of 440C, a colored wood handle with a stated handle length of 12.5 cm, handle width of 3.0 cm and handle thickness of 20.0 mm, and a net weight of 316 g. The Camping High Hardness Tactical Knife Fixed Blade Survival Knife listing names a high-carbon steel blade and a full tang design in its description, with the dimensions above.
The (B26) listing also notes that its product details are translated from the source listing. That is a provenance note about the text, not a claim about the knife. Figures and short material names tend to survive translation fairly intact, while descriptive wording depends on the translator, so a stated millimetre figure is a weaker reason for doubt than any prose on the page. It is still the listing's stated figure rather than a verified measurement.
Neither listing describes how the knife should be cared for or sharpened, and neither says whether the blade or any other part of the knife is user-replaceable or serviceable. Those are separate questions for the seller, and none of them can be settled by reading the thickness line more closely.
Comparing thickness figures across listings is only meaningful when you compare like with like. A 3.9 mm figure and a 5 mm figure are both stated dimensions, but the listings do not say they were taken at the same point or by the same convention, so the difference between the numbers does not by itself tell you how the two blades differ in shape.
Is 3.9 mm the same as 0.39 cm?
Yes. 3.9 mm equals 0.39 cm, and 5 mm equals 0.5 cm. The conversion changes how the figure is written, not what it measures, and the listings do not state where along the blade the thickness is taken.
Does the listing say whether the stated thickness is a maximum?
No. The listings state a blade thickness figure without naming the point along the blade or saying whether it is a maximum. Ask the seller if that detail matters to you.
Does the blade thickness figure tell me how the knife will feel or perform?
No. The line states one dimension only. The listings do not connect it to balance, handling, cutting performance or edge behaviour, and those are separate questions.
