Is this a scam??? Advice please!

[Fluid Power]

I own an industrial distribution business and about twice a week I get an email in the generic "sales@...." email address. It is always a misspelled mess. They all contain the red flags that accompany your typical scam. The people always want to buy something on a credit card and have it shipped. They always are asking for stuff that we don't carry. I realize it is a scam, but what is the angle they are working? Is there a way that my banking info is available to them by using a credit card? I feel I am reasonably smart but I cannot for the life of me figure this out. Any help or ideas is appreciated. I am not interested in selling anything to them, just trying to figure out the scam.

BTW they wanted smoke detectors, we sell pneumatic cylinders and valves.

Below is an email. Nothing was edited. The email address that this was sent from was from:

marry bill [[email protected]]

Hello Sales.
Am Marry Bill i will like to purchase for some product in your store and i want you to get back to me if you i can make order from your store and i want to know if you can shipp to the United state IN CARE OF NANA SMILES
1301 MAIN STREET
FITCHBURG
MASSACHUSETTS
01420
and i we make the payment by Credit Card
looking Forward To read from you now.
Wayne.S