grain direction and function

[Brian Krebs]

I know for self nocks on arrows; you don't want the arrow to split; so you shoot against the grain; and not with it.
 But with plastic nocks - does that make a difference?
 And how does an arrow perform with the grain being horizontal or vertical ?
 Does it affect spine?
Do arrow shaft sellers check the spine with the grain a certain direction; or is it more haphazard ?

[Dave Worden]

Arrows will spine differently depending on grain direction.  The arrow will be stiffer with the grain lines horizontal (the same way you'd do it for self nocks).  As far a arrow performance, I don't think it makes any difference except for matching the spine to your bow.  I believe shaft sellers check spine with the grain directions as mentioned above except, of course, for hex shafts where it makes do difference as far as I can tell.

[seabass]

grain direction makes a big difference.when the arrow is on the shelf or your bow,the grain should be horizontal.when on the spine tester,the grain will be vertical.when you make some arrows, your nock should be placed that when your arrow is on the bow and the nock is on the string,the grain will be horizontal.this is for paradox and it is also a safty feature.also make sure the rift in the grain on top of your arrow is facing towards the point end.good luck,steve

[Grey Taylor]

If the vendor or shaft manufacturer does not take the time to hand spine the shaft then the spine reading could be taken with the grain in any old direction on the spine meter. When we take this spined shaft and put it on the bow with the grain horizontal, we could effectively be shooting a different spine reading.
However, if the vendor or manufacturer hand spines the shaft then you (should) have a trained individual placing the shaft properly on the spine meter with the grain vertical, so when we shoot it with the grain horizontal, we'll be shooting the proper spine reading.
And yes, I believe it does make a difference.  

Guy

[seabass]

i second that greytaylor

[Brian Krebs]

 thanks

[onewhohasfun]

Brian re-read what Seabass said about safety. Watch out for runout of grain.Should be facing away from your bow hand.

[Grey Taylor]

Speaking of which...
I posted that exact question here a few weeks ago: does it really matter which way the grain runouts point?
I asked if anyone has actually seen an arrow split along those runout grain lines.
The consensus was: No, haven't seen it. Many of us have seen arrows split upon release, but no one posted that the splits have been along the grain lines.
However, we also pretty much agreed that we'd keep building wood arrows with the grain rifts on top of the arrow, pointing to the tip of the arrow... just in case.

Guy

[Don Stokes]

Re the grain runout, it depends on the species. Some woods have more of a tendency to fail along the rings than others. Generally, if the difference in the light and dark portions of the ring are very distinct and the transition between them abrupt, the wood will tend to fail along the boundary between the light and dark portions of the ring. Woods with a less distinct boundary between the portions of the growth ring will fail more randomly.