FMSI > Tube Nuts > Standard Steel Invert Flare Tube Nuts > Item # 4621 FMSIFMSI Tube NutsTube Nuts Standard Steel Invert Flare Tube Nuts Standard Steel Invert Flare Tube Nuts Item # 4621 Item # 4621, 5/8" x 7/8" - 18 Standard Steel Invert Flare Tube Nut 46215/8" x 7/8" - 18 Standard Steel Invert Flare Tube Nut Request Information Email This Page Download PDF Download PDF Printable Page Downloads FE The Officail Guide Book -TUBE NUTS - Ver2.pdf /Asset/4621.png /Asset/4621.png Close Window - For 5/8" tube - Invert flare with 7/8" - 18 thread- 7/8" hex head Unit of Measure Imperial Metric Both Specifications Tube Size N/A 5/8 in Thread Diameter N/A 7/8 in Threads per Inch N/A 18 T.P.I Hex Size N/A 7/8 in Packaging N/A SP(1) HP(1) Package Type N/A Barrel Units Per Package N/A 1