A flangeless fluid end comprising a fluid end body releasably attached to a connect plate. The connect plate is attached to a power source using stay rods. The flow bores of the fluid end are sealed without threading a retainer nut into the walls of each bore. Instead, the flow bores are sealed by bolting a retainer to the fluid end body. Plungers to drive fluid through the fluid end body are installed within removable stuffing box sleeves. These sleeves are maintained within the plunger bores by the bolted retainers. A number of features, including the location of seals within bore walls and carbide inserts within valve structures, aid in reducing or transferring wear.