.

Keeping this in consideration, do hard hats have an expiration date?

OSHA does not specify the service life of a hard hat, and there is no standard expiration time frame for hard hats. If you work under extreme conditions, such as exposure to high temperatures, chemicals, or sunlight, hard hats should be replaced after two years of use.

Secondly, how much force can a hard hat take? Back to impact protection, both types will withstand an 8 pound ball dropped from a height of 5 feet onto the top of the hard hat. Maximum peak force here would be 1000 pounds.

Also to know, how do you tell if a hard hat has expired?

To check the expiry date, you first need to find out when the hard hat was manufactured. It's this manufactured date that will be stamped onto the hard hat, usually below the brim, simply flip your hard hat over and take a look on the inside. You should see something that looks like this

Can you wear a baseball cap under a hard hat?

An additional cap or other object may limit this clearance. The bill of the baseball cap worn under a hard hat will not allow the head protection to sit level on the head, in the work position. North/Fibre Metal recommends NOT wearing a baseball hat under a hard hat.