Needles and nozzles need to be changed either because of coating compatibility or wear. The needle and nozzle combination needs to be changed if the needle no longer completely fills the nozzle hole when the trigger is at rest. Needles also need to be changed when they become bent. Needles and nozzels are sold as a set. When a needle is changed, the nozzle should be changed as well, and vice versa. There are three needle/nozzle sizes for all but the Professional HVLP gun:

• The light material needle/nozzle is used for thin coatings such as stain and polyurethane. The actual dimension on this set is .031 in diameter. If your gun has a logo embossed in the handle, the part number is HV7005. If the handle on your gun is smooth, the part number is MP301800AJ.

• The all-purpose needle/nozzle is used for coatings such as enamels and economy latex. The actual dimension on this set is .035 in diameter. If your gun has a logo embossed in the handle, the part number is HV7004. If the handle on your gun is smooth, the part number is MP301700AJ.

• The heavy material needle/nozzle is used for thick coatings such as primers and glazes. The actual dimension on this set is .040 in diameter. If your gun has a logo embossed in the handle, the part number is HV7006. If the handle on your gun is smooth, the part number is MP301900AJ.