A shot of the 5-star from Jim Aston page on fire starting in the rain :
This is a 5-Star Arvika single bit full size axe from Hults Bruks, designed for Australian hardwoods. The bit profile is very heavy with a lot of sweep to the convex edge bevel which is about three quarters of an inch wide. The edge also has a secondary bevel which is even more obtuse. The manufacturer notes that it should be sharpened before use, though it is still sharper than most hardware store axes. The head is skewed to the left however and the head/handle alignment is off. Considering that Jim Aston picked this one out, this doesn't say a lot for the current state of production. The Gransfors axes usually have straight heads, but even they have problems with head/handle alignment. The handle has decent grain however and is without and knots or other large problems but does come coated ("knobby") with a painted butt. The coating was sanded off and a coat of boiled linseed oil applied.
For felling, the penetration was very low considering the size and weight of the axe. It is easily out cut by the much smaller and lighter Gransfors Bruks Forest axe on Pine, Spruce, Juniper and Birch. The thicker bit profile of the Hults induces lower penetration and more acute chopping angles as otherwise the axe will glance. Thus large cuts cannot be opened and multiple notches are required. For limbing the work favors the Bruks axe even more as it was actually designed especially for that.
For splitting, the Hults works much better than the Gransfors Bruks Forest axe but a hardware store maul is more efficient in general for heavy splitting.
The secondary bevel was removed with a a few minutes with a bastard file, the edge was then honed with waterstones and finished on leather loaded with chroimum/aluminum oxide. This produced a noticeable increase in penetration however the Hults was still way behind the Gransfors Bruks Forest axe on local woods in terms of raw penetration and it still had to work at lower angles. Full swings from the hips were used with the Hults and swings from the shoulder with the Forest axe which is lighter and has a shorter handle. The Hults does not bind at all which makes for a more fluid pace, but the lack of penetration is far too much of a detriment.
Some relief was provided to the edge using a coarse sanding drum on a dremel, cleaned up with a bastard file and then honed with waterstones and finished on leather loaded with chroimum/aluminum oxide. Now the Hults stayed with the Forest axe on the softer woods and was more fluid. The extra reach of the handle also allows working closer to the ground. The edge still had no durability problems, it easily cut through the heavier knots with no edge damage, but the edge still sweeps out to to more than 40 degrees included so a high durability would be expected and the hardest local wood is black spruce.
More relief grinding was performed to reduce the edge to almost full flat. As with all edge reshaping, the more shoulder removed, the more metal needs to be remove to drop it down the same distance again. Even though this session was the same amount of grinding as the previous, it only resulted in a slight refinement. The edge on the Hults can go to 15 degrees per side without modification to the primary grind. The bevel is now only too obtuse in the last 75 thousands. With that profile the Hults saw a lot of use on felling trees of above four inches. It takes down pine of say 10-11 inches (a two hit span) in under a minute on a clean run with no knots, however the edge is still too thick for black spruce. The Hults now easily outperforms the Forest axe, but again this is a much lighter and shorter axe.
With use of the disk of a belt sander the Hults was later heavily reground, half an hour on the disk, and then fifteen minutes of filing. With the edge dropped back due to the grinder relief the edge can go down to 13 degrees per side and almost 3/4" wide. Here is a shot showing the initial profile, where it is now, and the straight lines are the minimum 13 degree profile :
With the very edge under 18 degrees, Hults has about two times the peneration of the Gransfors Bruks Forest axe. The Hults was still durable enough to cutting through some heavily knotty wood with no visible problems.
As a final extreme modification, a 4 1/2" angle grinder was used on the primary grind of the Hults to sweep out the side hollows. In takes hours of work and a lot of steel has to be removed and it is hardened steel which isn't easy to grind. The head was finished polished with a sanding disk (40 grit ZO), which removed all the little hollows from the grinding wheel. Here is a before and after shot :
The one on top isn't the axe which was reground however it is the same type. With the current profile it is similar in behavior to the Iltis felling axe.
The bit can be filed but not easily. It will easily last a full day of felling any only require light work with a fine hone at the edge of the day.
This is described as a hard wood axe but it is very difficult to get any penetration on even medium woods with the initial profile, very thick bits are usually reserved for soft woods. On woods that are very easy to cut a thin bit isn't needed as penetration isn't an issue and the profile instead has to concern itself with preventing excessive wedging thus the bits are thick with a lot of convex sweep. On hard wood axes it is difficult to get high penetration thus the edges are much thinner and the hollows much deeper. In short, the original profile of this axe would only work well on wood softer than clear pine.
With some grinding the axe turned into a very functional wood working tool and was used to fell a decent amount of wood. It does takes a fair amount of grinding to remove enough metal off of the axe to make it cut well and isn't practical without power equipment. Aside from the bit geometry, the other aspects of the axe were solid. The steel quality was good, taking a fine edge and holding it well, and sharpening ease. No problems with durability, even in extreme cases.
On one occasion the axe broke from a knot badly and smashed hard into a rock which had been covered by moss. The edge was damaged for about an inch on the extreme upper part of the bit. The majority was just impacted for about 1 mm or so, nothing major, however the very tip took a large lateral load because of the irregular shape of the rock. This resulted in a piece about 1/4" wide and 1/8" deep getting blown off. This was fixed by just grinding the the tip down a little as it would take far too much work to move the entire edge back 1/8" . Note the amount and nature of the damage could have been effected by overheating during the extensive reshaping.
Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com or by posting in the following thread on Bladeforums :
More information can be seen at the Hultafors website.
|Last updated :||01 : 10 : 2006|
|Originally written:||04 : 22 : 2002|