For 3/16" tube there are a total of 19 fittings (12 x 3/8"-24, 3 x 7/16"-24, 2 x 1/2"-20 and 2 x 9/16"-18)
Car SAE Brake Line Fitting Kit for Inverted Flares on 3/16 Tube (19 Fittings)
3/16" Brake Line Fitting Assortment – 16 Pc Zinc-Plated Tube Nut Set | SAE Thr
2 Brass SAE Brake Line Adapter 3/16 Female 3/8-24 X 1/4 (7/16-24) Male Inverted
2 Brass SAE Brake Line Adapter 1/4 Female 7/16-24 X 5/16 (1/2-20) Male Inverted
2 Brass SAE Brake Line Adapter 3/16 Female 3/8-24 X 5/16 (1/2-20) Male Inverted
2 Brass SAE Brake Line Adapter 1/4 Female 7/16-24 X 9/16-18 THREAD Male Inverted