Maker	Series	Flange Diameter		Barrel Diameter
OMS	20	6.1 mm	≈0.240″	Inside	3.4 mm	≈0.134″
Stimpson	#3	≈6.3 mm	0.250″	Outside	≈4.0 mm	0.158″
OMS	30	7.4 mm	≈0.291″	Inside	4.0 mm	≈0.157″
Moro	054	7.5 mm	≈0.295″	Inside	4.5 mm	≈0.177″
Stimpson	#2	≈7.6 mm	0.300″	Outside	≈4.5 mm	0.177″
Moro	052	8.5 mm	≈0.335″	Inside	5.0 mm	≈0.197″
Stimpson	#1	≈8.7 mm	0.343″	Outside	≈5.2 mm	0.204″
OMS	40	8.8 mm	≈0.346″	Inside	4.6 mm	≈0.181″
Moro	051	9.5 mm	≈0.374″	Inside	5.5 mm	≈0.217″
OMS	60	9.5 mm	≈0.374″	Inside	5.0 mm	≈0.197″
Stimpson	AA	≈9.9 mm	0.390″	Outside	≈5.5 mm	0.215″
Moro	050	11.5 mm	≈0.453″	Inside	6.7 mm	≈0.264″
OMS	70	11.7 mm	≈0.461″	Inside	6.2 mm	≈0.244″
Stimpson	#00	≈12.4 mm	0.490″	Outside	≈7.0 mm	0.277″