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Thursday, 5 July 2018

Holzfforma chainsaw bar review

 “Holzfforma” chainsaw bars from Huztl are very cheap and pretty rough. They need quite a lot of bar-doctoring before use and in the early hours of use to get them to work at all. They seem to be made from poor quality steel and tend to chip after a few hours use. I can't recommend them, but I have a few of them doing useful work for me. 
I have reviewed some other products from Huztl in my blog:
The good news is that most of the other Huztl products are better than the bars. 

August 2019 update
Recently Huztl advertised a new-looking chainsaw bar, still branded Holzfforma, but with different logos and printing on the bar, and stating "German Quality". Given that I've published a critical review of Holzfforma bars here, I thought I should buy a bar and see if Holzfforma has addressed some of their quality problems. 
Here's my new Holzfforma "German Quality" 20" bar, Stihl pattern. You don't have to say anything about the messy state of my workbench. 
I bought a 20" bar to fit Stihl (MS380, MS660 etc.) and had a look. 
In summary: this bar has the same over-gauged bar groove, needing hammering when new. The rails were better than the previous Holzfforma bars I've bought, but still required dressing before use. As for steel quality - the biggest problem with these bars - we'll have to give it a few hours work to find out. 
Two of my cut-down Holzfforma bars, attached to Stihl 024s, off to the forest to work thinning cypress
I’ve been using a few Holzfforma bars on a few of my Stihl saws over the last few months. They are astonishingly cheap: I’ve had an 18” long, 3/8”pitch, 1.6mm gauge bar delivered for under AU$12, when a genuine Stihl bar would be more than 10x this. If they were of reasonable quality they could save a lot of money. However I can't find any reviews online, and I note that most youtube videos by people making Huztl saw kits show branded non-Chinese bars attached.
For me, these cheap bars have allowed me to try things out without concern about wasting money. On these bars I’ve been trying out ideas: cutting bars shorter, using used frying oil as bar oil. If my experiments wreck a bar, I haven’t lost much, if they work, I’ve saved a lot of resources.

Trying out cheap bars might be interpreted as stingy. Maybe, but working out what is "good enough" is, I believe, a key to dealing with our overwhelming culture of consumerism. It's very powerful to work out what is good enough to do what you need to do, spend only as much money as you need, and live less as a slave to debt and status anxiety. 
After doing a lot of chainsawing with several these bars, I've concluded they are not "good enough". They have 3 main problems:
  • Rails out of square: the bar rails appear not to have been ground after laminating, leaving the rails out of square. This will cause the saw to cut a curve. It is relatively easy to remedy this with a file or linisher. All the Holzfforma bars I've bought have had this problem. 
  • Over-sized gauge: Every Holzfforma bar I've bought has had a bar groove way wider than its specifications, requiring repeated hammering to get the groove to the right gauge. 
  • Bad steel: with a few hours use, these bars develop chips in the bar rails, apparently due to discontinuities in the steel. These chips are bad enough to make the bars unusable. This has occurred in several different bars: 25" x 3/8" x .063" (2 bars chipped), 18" x 3/8" x .063", 16" x .325" x .063". 

Laminated bars

Typical laminated, roller nose bar, without a riveted-on roller nose
All the Holzfforma bars I’ve seen so far are of laminated construction. This means they are assembled from 3 layers of steel, spot welded together at multiple points. The middle layer is smaller all around than the outer layers, thus creating the chain groove. This construction is different from solid bars, sometimes referred to as “professional bars”, that are made from a solid plate of steel with a groove milled into the edge, and have a roller nose riveted on (unless they are solid nose).
Laminated bars are lighter and cheaper than solid bars, and good quality laminated bars are totally adequate for normal use.
All the shorter Holzfforma bars I’ve bought are normal laminated bars, with spot welding and an integrated roller nose.
The 3/8” pitch, 25” cutting length Holzfforma bar I bought for my Huztl MS660 kit chainsaw looked like a solid bar on the website, with a riveted roller nose. However on arrival I found the bar body is clearly laminated, as there are rows of spot welding marks on the bar. 

Here's the 25" bar on my Huztl 066. Looks like a solid bar with riveted roller nose - but it's not solid
Here's the riveted roller nose
If you look closely, you may be able to see the rows of spot welds (small circular dimples) parallel to the bar edge, showing that this bar is laminated, not solid
Is this faking it? I’m not sure, perhaps they use one roller nose for a range of 3/8” bars. I don’t mind that it’s not solid, but I suspect the riveted roller nose makes it a little weaker than a normal laminated bar. 

Bar rails

See the light shining under the rail on the left side, but not on the right? The rails are way out of square and not fit to carry a chain until it's been ground or filed square
The rails (sides of the bar groove, where chain side links slide) of Holzfforma bars clearly haven't been ground before painting and sale. Most are out of square when new, and need to be ground or filed before first use. I use a linisher attached to a bench grinder: grind the edges of the bar square to the bar face, and finish off with a light chamfer of the corners to reduce burring.

Steel quality

Holzfforma bars are made of carbon steel - you can tell by the way the spot welds are hard. This means the steel is harder than mild steel, but they don't appear to have been heat treated on the rails in the way genuine Stihl bars have to make them harder.
 The blue colours on the bottom edge of this genuine Stihl bar show it has been heat treated to make it harder
All my Holzfforma bars that have done significant work have developed serious chipping problems:
One chip on the outside of a Holzfforma .325" bar
Same .325" bar, another chip on outside
3/8" Holzfforma bar with a chip on the inside of the rails
My friend Pete made a Huztl MS660 at the same time as me, and also tried the same model Holzfforma 3/8" x 25" Stihl-pattern bar. After one day's work - without doing any preparation of the bar - it was a mess, with bad chipping of the rails on the sprocket nose. This bar wasn't hammered or dressed at all. Now it's useless. 
Another picture of Pete's bar from the MS660. Beyond repair. 
This is the roller nose of my Holzfforma 25" 3/8 bar - pictured up above on my Huztl MS660 - after a few hours use on an Alaskan chainsaw mill. It is starting to chip badly around the nose, despite not cutting with the nose area at all. 
Another picture of the chipping on my Holzfforma 25" bar.

And again - the nose is more chipped on the cutting side, seemingly getting damage where the chain comes off the sprocket. 
This is a bit strange, it's similar to the damage bars get if they've been badly worn and not dressed: large burrs can develop and break off, taking pieces of rail with them. Holzfforma bars feel very soft to file when dressing (Stihl bars are quite hard, a partly blunt file will hardly cut them), so it seems strange they show signs of brittle breakage. I've never seen this sort of chipping, unconnected to bad burring, on a chainsaw bar before. 
It doesn't look like these chips have been caused by my hammering, I've never had chipping with other bars after hammering, and my friend Pete's Holzfforma bar (pictured above) chipped very badly without any hammering. I expect it is due to steel quality - my old boilermaker father in law talks about working at times with poor steels that have invisible cracks from manufacture. 
As with all bars, keeping the chain sharp and the rails square will reduce bar wear dramatically, along with spreading the cutting up and down the bar (not just cutting at the base of the bar). On most cuts, the chain should be pulling itself into the wood, and not need to be pushed in with the bar rails. 

Bar groove gauge

Holzfforma bars are painted with a surprisingly tenacious paint, including the inside of the bar groove. Once the paint inside the groove is worn away by a little chainsawing, I find all Holzfforma bars are made with way over-gauge bar grooves: the chain can tilt way too far left and right because the groove is too wide. If the chain is perfectly sharpened, and the rails are nice and square, the saw will usually cut fine like this at first, but it will be trouble when everything isn’t perfect.
I hammer all my Holzfforma bars after a little sawing work has worn away some paint. After a few hours further use I find I need to hammer them again several times, as a little more wearing away of paint and steel quickly opens the groove again. 

Here's my video of how to hammer and dress a bar - in this case an old one:

It seems unfortunate that they’ve been made with such wide grooves. I’ve made one bar for an 024, using a 1.5mm Holzfforma bar (for Husqvarna) to take 1.6mm chain (standard for Stihl), by re-cutting the bar base pattern to fit. This has worked fine (but doesn't fix the steel quality problems). 

What else could go wrong?

There are various potential problems I haven’t experienced so far: failure of the sprocket nose bearing; bending of the bar with normal use. We'll see. 

Conclusion

Holzfforma bars are not worth buying with their current poor quality. If you’re going to use them, you need to be prepared to do some significant bar doctoring before first use, and again soon after. The bar doctoring skills and equipment needed to make these bars useable are useful for any chainsaw bar at some stage of its life.
For me, I don't regret trying these bars out, as they've enabled me to try a few things I wouldn't do with expensive bars. They've done a few dozen hours work for me, of significant value. The over-gauge bar grooves is an annoyance which can be managed with hammering. However, the chipping of the rails is a pretty terminal problem, which I think makes these bars not worth buying.