Nock Durability

[Steelhead]

The plastic used can be a factor in breakage.The really hard plastic is more brittle and prone to cracking breaking.

Softer plastic will not be as prone to cracking and or breaking.

[ed lash]

I've shot the GoldTip arrow brand since the 1990s. Over the last decade or two I've really liked the Traditional series. For sure, over the last few years, the nocks are different in my experience. They break more easily and also don't stay on the string as well. Not good.
So I've changed to Easton or Bohning and my problems have disappeared. All my "bad" GoldTip nocks have been white.

[Possum Head]

90% of nocks I have shot are GT. Years ago I had 2 fail in the same week so I canned the remainder and purchased new ones. No problems since. I attributed it to a bad batch and at the time learned others had experienced breakage as well. Two in many thousands of shots is all I’ve had.

[Rob DiStefano]

Guaranteed that all nock failures while shooting were hairline cracked before even nocking on the bowstring.

ALWAYS carefully check arrows before putting on the bowstring let alone shooting - 1st check is the nock integrity, 2nd inspect and bend the shaft, 3rd make sure the point or broadhead is well seated (use blue Loctite).

Most all brand nocks are good, I mostly use Easton or Bjorn.

[McDave]

I find before failure the knock will loosen up and not snap on string the same, most of the time. Flexing the ears also gets softer, ie. time to change.

I thought of this myself and was about to post it but thought it might be a good idea to look first to see if anyone else had already posted it.  So I second Katman's idea, and it deserves repeating.  I am alert every time I nock an arrow for the feel of the nock.  If the nock feels loose going on, it is probably cracked.  As soon as I find one that is cracked, I immediately pull it off the arrow and toss it into the bushes so I don't accidentally fire it later on.  I can't tell you how many dry fires this has saved me over the years, I’m sure more than 20. 

Of course, I’ve had the occasional nock break that was a complete surprise, too.  $hit happens.