Thread: Timber Hardness ?

the hardness rating for timber is called the janka rating. for blackwood the rating is 5.9kN seasoned. you might be able to google a table of results

what are you making?

a lot of info can be found here http://www.dpi.qld.gov.au/26_5447.htm

and the real hardies are up at 14 -16 find a chart

Thanks,

its for use in the making of snooker cues, for the buts and butt decorations.

anyone know where to find a chart?

ebony is the most commonly used timber.

regards
steve

so would be after weight then.

iv seen iron bark used but its not as heavy as some.

seams to be quite popular with a few makers in qld.

something like mallee would be great but hard to find in straight sections.

Brush Box, Tallowood, Turpentine, as Carl said Iron Bark, Blackbutt, Red Mahogany should still be ard enough and the list goes on. Spotted gum would be a good one too.

Here's a bunch of Aussie wood Janka hardnesses (in lbs force) from the supposed worlds top 100 hardest timbers taken from Wood Species Janka Hardness Scale/Chart site, these are all for 12%MC timber.
To convert from lbs force to kN divide these numbers by 220.

4270
Gidgee {Acacia cambagei}

3370
Box Grey {Eucalyptus microcarpa}
Mallet Brown {Eucalyptus astringens}
Wandoo {Eucalyptus wandoo}

3200
Casuarina {Casuarina equisetifolia}

3125
Gum Grey {Eucalyptus propinqua}
Ironbark Grey {Eucalyptus paniculata}
Ironbark Red Broadleaved {Eucalyptus fibrosa}
Ironbark Red Narrowleaved {Eucalyptus crebra}
Sheoak Rose {Casuarina torulosa}

2920
Bloodwood Brown {Eucalyptus trachypholia}
Box Grey Coast {Eucalyptus bosistoana}
Box Yellow {Eucalyptus melliodora}
Ironbark Red {Eucalyptus sideroxylon} 2

2800
Box White Topped {Eucalyptus quadrangulata}

2700
Gum Red Forest {Eucalyptus tereticornis} 2700
Gum Round Leaved {Eucalyptus denei} 2700
Messmate Gympie {Eucalyptus cloeziana} 2700

Missing from his list is

Gimlet {Eucalyptus salubris) 4190
Black Morrrel {Eucalyptus melanoxylon) 3460
Dundas Blackbut {Eucalyptus dundasii} 3960
Red Morrel {Eucalyptus longicornis} 3840
Salmon Gum {Eucalyptus salmonophloia} 3480

Raspberry Jam {Acacia acuminata} is probably over 3500

Wow, thats great info.

I found the janka hardness on wikipedia but it didnt have alot of the timbers I was finding from australian suppliers. also your link provided the hardness on olivewood which I couldnt find.

so thanks heaps.

I have been very keen on red morrel, and it looks like its super hard which is awesome.

thank you so much.
steve

One thing those tables don't tell you is that the variation between trees from the same species is as much as +/- 10% and the variation on the same tree can be much more. The hardness of a tree varies on where on the tree measurements are being made. Down around the tree base the hardness can be up to 15% more than on the main trunk. The hardness around branch unions also increases by 5 - 10%. Then of course there is sap wood and mature wood and heart wood.

An interesting fact is that the timber from the outer lower section (stump) of the every day coconut palm that grows on the beach has a janka rating recorded of up to 23 kn or around 5000 in the old scale and density of 1300kg m3. the older the palm the harder the timber. makes iron bark look like balsa.

Originally Posted by BobL

One thing those tables don't tell you is that the variation between trees from the same species is as much as +/- 10% and the variation on the same tree can be much more. The hardness of a tree varies on where on the tree measurements are being made. Down around the tree base the hardness can be up to 15% more than on the main trunk. The hardness around branch unions also increases by 5 - 10%. Then of course there is sap wood and mature wood and heart wood.

Good point, Bob.

Also plantation grown timber can be considerably softer than bush grown stuff.

For example, using the metric hardness scale, forest grown Tasmanian blue gum (E Globulus) usually has a janka in the range of 10 to 12. I have seen plantation Tas blue gum rated as low as janka 6.5. A big difference.

Cheers

Graeme

PS: I suspect the differential foe eco-ash - shining gum - E Nitens - might be even greater.