Norc 305 bolt markings

[emerson]

In addition to the machine stamped number to one side on the bottom of the bolt, there is a 1?3 28 hand marked on the center of the bolt bottom. Anyone know what this is?

 

[Claven2]

I suspect you have the numbers wrong - can you post a pic? It's usually a month and year of manufacture for the bolt itself.

 

[emerson]

I suspect you have the numbers wrong - can you post a pic? It's usually a month and year of manufacture for the bolt itself.

I'll look closer and report back. Thanks.

 

[Different]

In addition to the machine stamped number to one side on the bottom of the bolt, there is a 1?3 28 hand marked on the center of the bolt bottom. Anyone know what this is?

Does it look like an electropenciled marking? If it's a five digit number, I believe it.