Getting Down to Brass Tacks

Originated from textile industry.
In early American times, women would buy fabrics in large quantities. Merchants would try to cheat them by reeling the fabric out fast.
The merchants would have brass tacks on the table to indicate a yard. If they reel the fabrics out fast enough, they would be able to cheat a little.
The women buying the fabric realized what they were doing, and would exclaim, ‘You need to get down to brass tacks!’