Walk into any office building put up in the last thirty years and grab a door lever. Odds are good it's a Schlage ND. It is the Grade 1 cylindrical lock that ended up on more commercial openings than anything else in the country, for one reason: it takes abuse. Sixteen million cycles of it. But "a Schlage ND" is not an order. The function, whether the outside lever locks, when, and who can override it, is buried in a two-character code in the middle of the SKU. Get that wrong and you either lock your own staff out or leave a door that was supposed to secure standing open all night.

The Schlage ND-series Rhodes lever in satin chrome. Entrance and storeroom functions look identical from the hallway. The function code in the SKU is the only tell.

Grade 1 is the whole point. Don't buy down.

The temptation on a budget is to grab a residential-grade lever off a big-box shelf and call it commercial. On a door that gets hit forty times a day, that lever is loose in a year and broken in two. I've replaced enough of them to stop feeling bad about saying it. The ND is ANSI Grade 1, the top commercial rating, tested to 16 million cycles. On a high-traffic office door that's the baseline, not a luxury. Buy the grade the traffic demands. The lock costs more than the residential special once, not every eighteen months.

Read the ND model number

Take a live SKU: ND53PD-RHO-626. Reading it: ND is the series. 53 is the function, here entrance/office. PD is the lever-with-pull design family. RHO is the lever style, Rhodes. 626 is satin chrome. The two characters after ND are what decide behavior. Everything else, lever shape and finish, is looks. The function number is the lock's job.

The three functions you actually choose between

ND53PD, entrance/office. This is the office-door default. The outside lever locks and unlocks with a key, and there's a push-button or thumbturn inside so staff can lock up from within without a key. Come in first thing, unlock it, leave it open all day, lock it when you go. The ND53PD in satin chrome is the one that goes on the majority of private-office and suite-entry doors. If you're not sure which function, it's probably this one.

ND80PD, storeroom. Outside lever is always locked. A key retracts the latch to get in; the lever never unlocks, so the door secures itself every time it closes. No button, no thumbturn, no way to leave it accidentally open. That's the whole point. IT closets, supply rooms, mechanical spaces, anywhere "did someone leave it open?" can't be a question. The ND80PD storeroom is what I put on every door that has to stay secure without anyone thinking about it.

ND70PD, classroom. Outside lever locks and unlocks by key only, no inside button. A teacher locks the door from the hallway with a key, and the inside lever always lets people out. Schools, and any room you want lockable from outside but always egress from inside. Different order. Ask for classroom function by name.

Lever style is looks. Handing and backset are not.

Rhodes, Athens, Sparta, Tubular. Those are lever shapes. Pick by taste and by matching the rest of the building. The ND53PD-ATH in satin chrome is the same entrance lock as the Rhodes above, just wearing the Athens lever. Underneath, identical. What is not just looks is the door itself. The ND is a cylindrical lock and most cylindrical levers are field-reversible for handing, but confirm door thickness and backset before you order. Standard backset is 2-3/4 inch on commercial prep, 2-3/8 on residential-depth. Measure it. Order a 2-3/4 for a door bored at 2-3/8 and the latch won't line up. A lock that doesn't fit the prep is a return, not an install.

Common questions

Entrance or storeroom for a private office?

Entrance (ND53PD). Staff leave it unlocked during the day, lock it from inside when they go. Storeroom only if the door must secure itself every single time it closes.

Is the ND better than the residential Schlage at the hardware store?

Yes, and it's a different product. The ND is Grade 1, 16-million-cycle commercial. On a door used all day, buy it.

Does the lever style change the function?

No. Rhodes, Athens, Sparta are shapes. The function is the number after ND. Pick the number for behavior, the style for looks.

What finish?

626 satin chrome is the commercial workhorse. 613 oil-rubbed bronze and 605 bright brass for a warmer look. Same lock underneath.

What to have before you order

The door's job: office, closet, classroom, front entry. Whether the outside lever can ever be left unlocked. Door thickness and backset. Finish to match the building. That's the whole list. With it, the SKU falls out. ND for the series, the function number for the behavior, a lever style you like, a finish that matches. If you want the fuller walkthrough of buying Schlage commercial online, ND versus the L-Series mortise versus the B600 deadbolts, start here: Where to Buy Schlage Commercial Locks Online.

Lock Depot stocks the Schlage ND line in entrance, storeroom, and classroom function, every lever style and the standard commercial finishes. Start at the Schlage hub, or call 877-365-5625 and tell us the door's job. No phone tree. Answer the one question, can it ever be left unlocked, and we'll read you the exact function code you need.