This comes off of a DeWalt Powerwasher DP3750. The Dewalt part number is 18300. Specifications are 375-16X1.75 FL. They want 7 bucks for this bolt online.
Drilling down here (to find later at fastenal) closest I can seem to come is this one.
https://www.boltdepot.com/Product-Details.aspx?product=17258
What's giving me pause is another bolt that is on the power washer has a "10" stamped on the head of it. I can't find that anywhere. The bolt holds the pump onto the engine.
Any ideas how to get this locally?