Waterway Heater Part: Split Nut Screw 50087.

 Stainless steel, self-tapping number 8 x 5/8 screw,.

This heater split nut screw works with 1 1/2 inch heater split nuts.

Split Nut Screw 50087 Self Tapping 8 for 1 1/2 Inch Split Nuts - most split nuts use 2 of these.