O Coupler Reference Charts

Shank Offset

Underset Shanks effectively move the coupler head up about 0.100" from the centerline of the shank. This allows for proper alignment of couplers when used with different rolling stock or alignment needs.

Centerset Shanks keep the coupler aligned with the centerline of the shank. This is the most commonly used offset, and the best place to start when fitting new couplers to rolling stock.

Overset Shanks effectively move the coupler head down 0.113" from the centerline of the shank. This design can help align couplers among different rolling stock.

Underset Shank	Centerset Shank	Overset Shank

Shank Length

Short Length Shanks have a 15/16" (0.938") length measured from the front face of the coupler head to the rear face of the gearbox.

Medium Length Shanks have a 1 9/64" (1.140") length measured from the front face of the coupler head to the rear face of the gearbox.

Long Length Shanks have a 1 25/64" (1.390") length measured from the front face of the coupler head to the rear face of the gearbox.

Short Length Shank	Medium Length Shank	Long Length Shank

Head Styles

Standard Heads are slightly over scale but are great for use on tracks that might have bumps and uneven surfaces. Compatible with all Kadee® head types.

New Generation Type E Heads feature an intricately detailed head design perfect for modeling the Type E coupler era.

Standard Head	Type E Head

O Scale Coupler Chart

Use the chart below to find your ideal coupler.

We do not recommend mounting a metal coupler directly onto a metal surface or in a metal gearbox. Doing so may allow electrical crossover from the track into the train causing shorting or damage.

Always check for proper coupler height using our #812 O Coupler Height Gauge.

			Plastic Knuckle Plastic Shank Standard Head	Metal Knuckle Metal Shank Standard Head	Metal Knuckle Metal Shank Type E Head
Short Shank	Centerset Shank	Plastic Gearbox	806 #806 Coupler with #806 Short Gearbox		743 #743 Coupler with #806 Short Gearbox
Medium Shank	Underset Shank	Plastic Gearbox			747 #747 Coupler with #817 Gearbox
	Centerset Shank	Plastic Gearbox	800/801/804 #800, #801, or #804 Coupler with #817 Gearbox	816 #816 Coupler with #817 Gearbox	745 #745 Coupler with #817 Gearbox
		Metal Gearbox		805 #805 Coupler with #818 Gearbox	740 #740 Coupler with #818 Gearbox
	Overset Shank	Plastic Gearbox			742 #742 Coupler with #817 Gearbox
Long Shank	Centerset Shank	Plastic Gearbox			746 #746 Coupler with #817 Gearbox