By Kent · Lock Depot Staff Writer

The 4040XP article covered the heavy door that slams. This one is about the other problem: the door in an abused spot, a school hallway or a stockroom or a gym, where people fling it into the wall and lean on it. For that opening you don't just want a strong closer. You want the arm mounted so it can't be levered off. That's the LCN 4110 Smoothee with the extra-duty parallel arm, and the mounting is the whole story.

Parallel arm, why it survives where a regular arm dies

A standard (regular) closer arm sticks straight out from the door and hangs in the traffic path. On an abused door, somebody grabs it, swings on it, or props something against it, and eventually the arm bends or tears out of the door. The parallel arm folds back flat against the door face instead, tucked up under the closer. Nothing sticks out to grab. On a school corridor or a rec-center door, parallel-arm mounting is the difference between a closer that lasts and one you're back to replace in a year. I won't spec anything else for a high-abuse opening.

The EDA arm, the part that takes the punishment

EDA stands for extra-duty arm. It's a beefed-up forged arm and a heavier shoe (the bracket that anchors to the frame) built to eat abuse a standard parallel arm can't. On a door that gets kicked or blown open into its stop, the shoe is usually what fails first, the forces try to rip it off the soffit. The 4111-EDA puts the heavy shoe and the forged arm on the door from the start. If the location is rough, this is the arm to buy. Don't cheap out on the arm and keep the good closer body; the arm is where the failure lives.

Sizing the spring for the door

The 4110/4111 is adjustable across a spring-size range, so one closer covers a spread of door widths and weights. Turn the spring up for a wider or heavier door, down for a light one. But adjustable has a ceiling, a genuinely heavy, wide exterior door wants the bigger 4040XP body from the other article, not a 4110 cranked to its limit. Match the closer to the door. Overworking a small closer on a big door just wears it out fast.

Finish and hand

Surface closers show, so match the finish. US26D satin chrome for most commercial jobs, or grab a dark bronze if the building's hardware runs bronze. The LH/RH in the part number is the hand, for a parallel-arm surface closer, get us the door's hand so the arm and shoe land on the right side. Wrong hand and the geometry fights the door instead of controlling it.

Common questions

What does the parallel arm actually do for me?

It folds the arm flat against the door instead of sticking out into the traffic path, so nobody can grab or lever it. On an abused door it dramatically outlasts a standard arm.

What is the EDA arm?

Extra-duty arm, a forged arm and heavy shoe built for high-abuse doors. On a door that gets kicked or blown open, the shoe is what usually fails; EDA is the upgrade that stops that.

When should I step up to the 4040XP instead?

When the door is genuinely heavy and wide (a big exterior entrance). The 4110 is the abuse-resistant hallway/interior workhorse; the 4040XP is the heavyweight for slamming exterior doors.

Do I need to know the hand?

Yes, for parallel-arm mounting. Give us left or right hand so the arm and shoe mount on the correct side.

Lock Depot stocks the LCN 4110/4111 Smoothee with the extra-duty parallel arm, in the common finishes, handed for your door. Start at the LCN hub, or if your problem is a heavy exterior door slamming, read LCN 4040XP: Stop a Heavy Commercial Door From Slamming. Or call 877-365-5625 with the door's hand and how rough the location is, and we'll spec the arm and shoe to survive it.