Auray 5/8" Male to 3/8" & 1/4"-20 Female Combo AD-COMBO-S B&H
Amazon.com: M20 to 1/2" Inch NPT thread adapters. ( $8.44 Each - Sold in 10 Packs ) M20X1.5 threads on external side. 1/2" Inch NPT threads on internal side. Nickel plated brass
PRECISION ARMAMENT THREAD ADAPTER 1/2-28 TO 5/8-24 | Brownells
Amazon.com: PATIKIL M10/M12 to M6/M8/M10 Reducing Screw, 6 Pack 15mm Long External Thread Adapter Reducer Convert Joint Hardware Double Male Thread Bolts : Industrial & Scientific
Kaw Valley Precision Barrel Thread Adapters | Wing Tactical
M4 Muzzle Thread Adapter | single point cut | suppressor thread adapter
WindTech 3/8-16 to 1/4″-20 Female to Female Thread Adapter | Wilcox Sound and Communications