This bolt should have a head on it for a wrench. This goes with the replacement deck roller which is great, but over time the hole for this bolt wears and the bolt must be held with a wrench in order to tighten the new roller. I had to file two sides of the bolt head in order to lock a pair of vise grips on so that I could tighten the lock nut. I suspect 99% of people replacing the deck roller with this carriage bolt will have the same problem. It would have been so much better to have a bolt with a head that I could have simply put a wrench on to tighten.