How much deflection does a 45-pound bow need?

Depending on the length of the arrow, it is generally 400 to 600 deflection.

Deflection is the linear displacement of the axis of the rod in the direction perpendicular to the axis or the linear displacement of the middle plane of the plate and shell in the direction perpendicular to the middle plane when the force or temperature changes unevenly. Deflection refers to the hardness of the arrow. The higher the number, the softer it is, and the lower it is, the harder it is. Bow and arrow match soft hardness, 400 is harder than 500. According to the number of pounds and pulling distance of your bow, choose the deflection that suits you.