Certification or license requirements vary by region, so you'll have to check with your local and state regulations offices to find out. In the meantime, I recommend that you visit a local hardware store and see if there really is a market for your product.

If so, the hardware store owner or manager should put you in touch with purchasers at higher levels to see if your product is something they may want to stock. You can also go to industrial wholesalers or suppliers in your area or region to see if there is a market or interest from their perspective.

The biggest key is finding out who your customers are and where they reside, and what key benefits and solutions your product offers or provides. Then, work backwards to determine which distribution channel is best to sell your product (retail, wholesale or even online).

Related: Landing a Spot in the Retail Big Leagues
Related: Determining the Price of Your Goods or Services