Handle Wood Growth Rate

E

Ernest DuBois

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Mar 2, 2013
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It's one of various things to judge a good handle wood by, but on this piece, sent up recently from out of the southern France regions were it was the sought after species by the old timers locally, it's a wood species that combines two favorable features, density for strength and modestly spaced growth rings for resilience, toughness or flexibility. It's not so common, normally you get one or the other of these two characteristics. A dense hardwood formed by a slow growth rate characterized by tightly spaced annual rings, is typically on the brittle side, and a hardwood with good flexibility from a faster growth rate, seen in wider annual growth ring spacing, will be less dense and be relatively weak.

This mountain Ash has relatively wide rings but the wood is dense and heavy.


E.DB.
 
Good post.

For hickory the USFS determined that 5-20 growth rings per inch was optimal, but that good resilient wood was found at up to 40 growth rings per inch. Some railroads used to specify that the providers of striking tools use handles not exceeding 20 growth rings per inch.
 
Looks like a nice piece of lumber. Nice post. I've had very good luck with the small number of ash handles that I have.
 
The optimal range with those numbers seems meaningless to me - questioning USFS - being so broad, 5 to 40. Such a range would cover just about anything, in hickory I understand.
The piece in the picture up, is more than an inch, at ca 30 mm it is something like an inch and 1/4 and by my count between 7 and 9 annual growth rings i.e. combined early and late wood accumulation over a year, puts it at moderate to fast growth rate.
This is more standard ash, down, from this area. The growth rate looks like something around 15 to 20 annual growth rings per inch, leaving open the question of density or weight per unit.
 
Ernest DuBois said:
being so broad, 5 to 40.
Click to expand...

5-20 is the recommended range. 2nd growth hickory often falls in this range.

From 'The Mechanical Properties of Wood' Samuel J. Record, M.A, M.F. Professor of Forest Products, Yale University

Growth%20rings%20-%20mechanical%20properties%20of%20wood.jpg


Pennsylvania Railroad just specified less than 21 growth rings per inch.

http://prr.railfan.net/standards/standards.cgi?plan=77900-B&frame=YES
 
This always amused me. How many rings per inch. I have handles that are so compact it is tough to count the rings, and one with big old broad wide rings, and I have never had an issue with either, and long as the grain didnt run out. I love "stats". Good topic though, see others opinions and findings, maybe there is logic to it.
 
I have considered using Mountain ash for an axe handle, but it is incredibly difficult to split, its like the fibers dont run in straight lines. Ash is much nicer to work with.
 
I think the problem in some ring-porous species is the porous vessels are in the summer wood and not the wider spring wood so if there are more rings per unit area, then there are more pores, which would tend to make the handle weaker. Although I have some older axe handles too with very close rings that are very sound. Runout is more important.
 
A single annual growth ring is composed of two different kinds of woods, early wood representing the quick growth rate of the growing season and late wood, put on when the growth rate slows down, demarcated then at the point which the cycle starts again. Halfaxe wants to break it down further and divide the growing season into spring and summer. OK, but it's a different distinction than is indicated by the visible rings. Ring porous woods, with the pores, as seen by looking at the end grain, grouped in the early wood, typically make the best wood for handles - that is not to say that all ring-pourous woods are equally good for handles, but the best handle will be of ring-porous wood. The configuration of pores, bunched up as they are in the early wood provide a cushion against shock, (maybe we can see this as being absent in diffuse porous woods like maple for example or beech) - to me this attribute seems self evident, and to go along with that, the wood can be separated along the rings by crushing it there where the pores are congregated, an indirect indication of its resilient nature. The late wood, the typically much smaller darker half of the ring, is dense and harder and provides strength, that is to say is more crush resistant. The interesting thing about the mountain ash there is that the early and late wood bands are about the same size, not unique among woods but it makes it particularly suited for axe handles.
 
Ernest. That early wood is good for nothing. And I would not discount diffuse pores woods at all.
With ring pores wood its all about the late wood to early wood ratio. Its that simple. Most of the time you will have a better ratio with the younger trees but there are always exceptions. Both ways.
I understand what you are saying about early wood, but I just don't buy it. I think any perceived benefit of more early wood in a handle would just be from a weaker lighter handle.
 
The early to late wood ratio surely is a consideration, along with the overall spacing and growth rate, weight and hardness and density. The ratios are typically, more early wood to late wood with the result that in fast grown wood the density, mass and weight will go down and in slow grown wood the early to late wood ratios are typically closer together, that is while the early wood sections will probably be thicker than the late wood, the difference wont be as big, and the density and weight and strength will go up at the same time the wood will be more brittle and break sooner, that is, it will be less resilient. The closest thing I can imagine to an early woodless wood would be something like boxwood. I don't want a handle from boxwood, personally, so I guess I don't understand what you mean by saying the early wood is good for nothing. And then it gets to the particular case of the wood above because this is exactly the point, that the early wood, which is normally less dense, in this piece is very dense and hard. So, even with an even early wood to late wood ratio, this wood is heavier than the more standard ash represented in the second picture, meaning the benefits I think you are getting at, density, good weight to mass, and, in addition the resilience provided by the early wood.

E.DB.
 
Nope, Early wood is just along for the ride. Contributing very little to the strength of the wood. The more late wood the stronger it will be. Density will go up also. In ring pores hard wood the faster growing trees almost always have a better late wood to early wood ratio. That's why second growth hickory has been prized for axe handles.
 
A tight growth ring pattern is an indication of slow growth.

Wider spaced growth rings show a faster growth rate.

In the top picture the demarcations are more clear and shows the pores grouped in the early growth and then the transition to the darker more dense late wood. The late wood makes up slightly more of the 100%

In the bottom picture the transition early to late wood in not demarcated so much by a lighter and darker version of the wood, even though they are both pictures of ash wood, but that's more indicative of other conditions, the point being the pores and their congregation at the beginning of the growing season.

There is not a question of one type of wood being stronger than the other, more a matter of the contribution each part of the wood makes to the whole. I cannot agree that the early wood has no function, (less strength yes, no function is an overstatement I disagree with), and have said that the advantage this configuration offers over diffuse porous woods is greater resilience from the shock absorption effect of the pores grouped together there in ring porous woods.

I wonder Garry, given only the point of view in these pictures, which you would choose for a handle? I know which one I would.

E.DB.
 
Wow, this thread is confusing to me! So, take this ash handle for instance. In my experience, the porous rings are weak and brittle and the dense rings are strong and resilient. I try to get the highest ratio of dense, smooth wood vs. porous wood as I can. So, this handle has nice structure. I'm pretty confident that Garry will agree with me. Ernest, however, do you agree or disagree? I'm confused by all the big words.

IMG_7487.jpg
 
How are growth rings counted? Do you count the late and early growth as 1 or 2 rings?
 
A good question and I think you are likely to get answers affirming both of the options. i see it this way. One ring is the total amount of wood added over a growth cycle of a year, late and early growth is one year. Looking at the top picture, if you were to count each alternating ring of light and darker color you would then want to divide by two for the age of the tree.

But I ask this question first. What measure or means do you use to determine the relative strength or weakness of porous early wood versus late, dense wood?

E.DB.
 
Yeah I'd have to say that I put way more emphasis on grain orientation, lack of runouts, and lack of porosity than I do number of growth rings per inch or sapwood/heartwood. My Gransfors Bruks Scandi was my first real axe that I used regularly and it has some pretty dense growth rings (pic below). I had one or two somewhat nasty overstrikes on hardwood when I was first getting used to it and the handle under the eye only slightly dented with no signs of cracking.
P1050595.jpg


If porous wood is more common in fast growth, wouldn't a higher number of growth rings be the safer bet?
 
Ill summarize it -

1. Get handle.
2. Put in axe/hatchet head.
3. Use said axe/hatchet.
4. Enjoy.

Or you could do this -

1. Hire BioPaleoStarTrekDendrologist to check you handle for appropriateness.
2. Test handle at local NASA station for required specs per guidelines.
3. Affix winning handle to axe head.
4. Use handle once then it breaks.
5. Repeat search for the Holy Handle.
 
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