By Federico Buldrini
This puukko was crafted by Johannes Adams, a young German bladesmith living and working in Hatten, 50 km W of the Hanseatic city of Bremen.
Since the steel featured is seldom used on puukkos it’s worth spending few words on its origin, at least in Germany. 1.2516 was firstly produced in the 70s for paper sheets cutter blades, but due to its high production costs was subsequently discontinued and substituted with 1.2210, the current K510.
Adams sources the steel from an old warehouse owned by a friend.
Compared to K510, 1.2516 has way less chrome, but 1% of added tungsten, which should form tighter and harder carbides, hence giving more wear resistance and edge stability.
The birch bark used comes from the Espoo area and is provided to the maker by a Finnish contact.
length 95 mm
width 22 mm
thickness 2 mm at the spine, 4,5 mm at bevels junction
tang 7×2 mm at the pommel
steel W-Nr 1.2516
edge angle 20 °
hardness ~ 62 HRC
length 99 mm
width 31 mm
thickness 22 mm
knife 110 g
with sheath 160 g
The blade was forged by hand held hammer from a bar of 1.2516 (K405). It has a rhombic section, slightly tapered in height. After annealing and normalizing it was heated in the forge, quenched in boiling oil and tempered thrice for 30 minutes at 200° C in oven. The blade is hardened so to leave the spine and tang softer. The bevels are ground to 20 ° and the edge taken to virtually zero.
The handle is made of birch bark discs compressed between two 6 mm brass bolsters. It’s sanded to a fine grit and it’s slightly tapered in both directions in wideness and thickness. It has a subtle teardrop section.
The sheath is crafted from 2 mm thick leather. It’s hand stitched and perfectly holds the knife. Inside there is a pine liner. The belt loop is fixed with a brass D-ring, The loop itself is closed by a brass rivet.
The puukko is roughly the same size as Victorinox large locking models.
Out of the box I detected few tiny asperity along the edge, quickly reduced with stropping. While I was whittling to get the feel of the knife it proved nimble, but lost the sharpest bite quite easily. Thus I added a hint of microbevel, and the steel was just a bit longer to sharpen than K510 at 60 HRC or 52100 at 62 HRC.
Now to my usual documentation. This time I carved the twig troll from hornbeam, a hardwood comparable to hickory. I felt a light resistance while cutting away chips and during roughing cuts, the acute geometry perceptibly divided the fibers. No problem during refining cuts. After this the shaving bite was gone in all the flat portion, but the edge was nonetheless completely pristine.
I stropped the puukko to get the shaving bite back and up we went with the dry silver fir spatula. Again I felt some resistance during roughing cuts due to the acute geometry. The knife had a very good bite anyway, felt agile, balanced and intuitive. The trickiest part to carve, as usual, was the junction between the spatula and its stem: it’s all endgrain. I felt some bite loss towards the end of the work, though the edge was still leaving a shiny finish on the wood. At the end it barely shaved.
Two words on the steel performances.
I’ve noticed that the other carbon steels I’ve tried on puukkos (K510, 80CrV2, C75 and 52100) even after stropping with a #12000 compound, all have kept micro toothy edges, in different degrees. While this 1.2516 gets absolutely smooth and toothless. I felt like this extreme edge finesse may have caused the faster shaving bite loss I detected.
Generally speaking I found the sheath to be slightly bulky. Shaving the liner down of a couple of millimeters per side might be better, but that’s just a personal preference. The puukko has proved to be slightly more resilient than 52100 at 62 HRC and K510 at 60 HRC, given the same geometry. Edge holding was just a hair inferior, due to the edge finesse I wrote about earlier. The handle is slightly shorter than what I’m accustomed to, but due to its generous wideness and thickness, it doesn’t really feel small at all. It was also pleasantly agile, despite its wide proportions.