Narrow Shank Couplers for HO and HOn3

These couplers feature the same coupler head design used in the compatible shank couplers. However, these have a shank narrow enough to be used in true scale size draft gear boxes. Unless otherwise indicated, couplers are supplied with highly prototypical Accurail® PROTO HO scale size draft gear boxes and mounting screws.


Part # Description Price Status Buy Now
ENC87K 6 Easy-to-Assemble Die Cast AAR Type E (no boxes included) See Accurail Site to order boxes from them. (Accurail Item #1031 or #1081.) $7.50 Stock Item
ENC87KB 144 Easy-to-Assemble Die Cast AAR Type E (no boxes included) See Accurail Site to order boxes from them. (Accurail Item #1031 or #1081.) $96.00 Stock Item
RNC87K 6 Easy-to-Assemble Die Cast Sharon Couplers (up to about 1940). No draft gear box or mounting screws included. Suitable for both HO and HOn3. Note that we do not recommend assembly of these kits without the AFRN assembly fixture listed below. See instructions here. $8.00 Stock Item
RNB87K 6 Easy-to-Assemble Die Cast Sharon Couplers (up to about 1940). No draft gear box or mounting screws included. Slightly shorter shank than RN87. Suitable for Blackstone Models and other HOn3 equipment. Note that we do not recommend assembly of these kits without the AFRNB assembly fixture listed below. See instructions here. $8.00 Stock Item
RNB87KB 144 Easy-to-Assemble Die Cast Sharon Couplers (up to about 1940). No draft gear box or mounting screws included. Slightly shorter shank than RN87. Suitable for Blackstone Models and other HOn3 equipment. Note that we do not recommend assembly of these kits without the AFRNB assembly fixture listed below. See instructions here. $108.00 Stock Item

An MS uncoupling wand is required to operate the couplers. This wand is simply a custom made industrial strength magnetic rod which lifts the internal steel ball in the coupler allowing it to open. The wand has a wire attached to one end aid in aligning couplers in preparation for a tie as well. We don't recommend building your own uncoupling wand from magnets you may have lying around. Customers who have tried this have reported less than satisfactory results.A magnet that is too strong will prevent the couplers from later locking after uncoupling. A magnet that is too weak won't unlock the couplers reliably. Click here to see how to use the uncoupling wand.

Part # Description Price Status Buy Now
MS Local Uncoupling Tool $6.00 Stock Item

Type E and Sharon couplers are pretty forgiving as far a coupler height goes. Tightlock couplers (type F and H) are not. This Sergent Engineering coupler height gauge is a go/no-go type gauge so there is no need to guess whether or not coupler height is close enough. If the knuckle slips into the groove on the gauge, you are good to go. Limits for the gauge are of course based on the 32.5" to 34.5" prototype limits. The gauge is cast in tooling resin so dimensions won't creep over time.

Part # Description Price Status Buy Now
HG87 Coupler Height Gauge $5.00 Stock Item

The IFN Installation kit contains metal templates and an appropriate drill for accurately locating draft gear box mounting holes on rolling stock. It works equally well for all Sergent Engineering narrow shank couplers.

The AFN fixture is very useful when assembling EN87K kits. It is precision cast in tooling resin so its dimensions won't change over time.

For the Sharon coupler kits, an assembly fixture is not really an option, but a requirement. The RN87K and RNC87K share the same fixture. The RNB87 requires a different fixture because of its shorter shank.

The RM40 reamer is useful when installing Sergent Engineering narrow shank couplers into existing draft gear boxes.

You'll probably want a couple of extra ball and spring packets, too. Even though Sergent Engineering will gladly replace these small parts at no charge if they happen to get lost during assembly, you might want them more quickly than we can send replacements. These are cheap and nice to have on hand.

Part # Description Price Status Buy Now
IFN Installation tools for EN87 $5.00 Stock Item
AFN Assembly fixture for EN87K $8.00 Stock Item
AFRN Assembly fixture for RN87K and RNC87K $8.00 Stock Item
AFRNB Assembly fixture for RNB87K $8.00 Stock Item
RM40 Mounting hole reamer for narrow shank couplers $15.00 Stock Item
BP87 Spare Ball Bearing and Spring Pack for EC87/EN87 $1.00 Stock Item
BPR87 Spare Ball Bearing and Spring Pack for Sharon Couplers (same balls, much lighter springs) $1.00 Stock Item

Couplers that have the cut lever attached on top are referred to as "top operating" Couplers that have the cut lever attached at the bottom are referred to as "bottom operating". The type E coupler modeled by the EN87 was always available as a bottom operating coupler, even though the top operating version seems to have been preferred initially. Sergent Engineering offers two items to assist the modeler in adding these special details.

The BCL87 contains 10 etched brass cut lever linkages. These linkages fit into slots on the bottom of the coupler as shown in the picture. These brass etchings fit the E, SBE, and SE style couplers. The cut levers (not included) should be inserted through this linkage in a manner that allows the coupler to swing from side to side.

Type F couplers are almost always bottom operated and the linkage is mostly hidden by the coupler casting. A "J" shaped small diameter wire can be used to simulate the linkage for these couplers. The Sergent Engineering type F coupler head provides a shallow locating hole for this wire.

For those that desire to model top operating couplers, Sergent Engineering offers drilled top coupler castings which will accept lift rings. This option should be ordered at the same time coupler kits are ordered. Lift rings should be installed prior to assembly of the couplers since there is a risk that glue used to attach the rings may also make its way to the locking ball inside the coupler. For this reason, the drilled tops are only an option for kits - not assembled couplers.

Holes in top castings are created with a #80 drill. We recommend either bending your own eyebolts from 0.010" wire or using Grandt Line #5085 eyebolts (or #86085 if you would rather have the equivalent in brass) for this application.

Part # Description Price Status Buy Now
BCL87 10 Etched Cut Lever Linkages for EC87/EN87 $2.00 Stock Item
DRLEN Drilled Top Option for one pkg EN87K $1.00 Add 1 week for delivery