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Quick Verdict

Corbin Russwin hardware is ordered by series plus function number plus trim code. ML2000 is the mortise lock, and the digits after ML20 set the function: 10 passage, 30 privacy, 51 and 54 entrance or office, 52 classroom intruder, 55 classroom, 57 storeroom, 70 full dummy. ED5200 is the standard-stile rim exit device (4-1/2" minimum stile), ED4200 is the narrow stile version (2" minimum stile), and ED5200A is the fire rated build. DC3200 and DC3210 are Grade 1 surface closers, with A1 meaning hold open arm and M54 meaning sex nuts and bolts. Electrified work uses ML20906 (fail secure mortise) and ED5200 MELR (motorized latch retraction). The 8000-7 is the 7-pin large format core. If you hold an old part number, match series, function and finish before you match anything else. Everything below ships same day on orders before 3:00 p.m. EST.

What do the ML2000 function numbers mean?

The ML2000 is a heavy-gauge mortise lock with a 5-7/8" x 4" x 15/16" lockcase, a 2-3/4" backset, a 1-3/4" standard door and a quick-reversible hand, so a lock can be re-handed without opening the case. The function sits in the model number: ML2010 is not a different lock body from ML2051, it is a different internal function. That is why the same case accepts any ML20xx function and why the parts page for the ML2000 parts and accessories is the busiest Corbin Russwin page on the site.

Function number	Function name	Typical room	Lockable side
ML2010	Passage or closet	Corridors, closets, utility rooms	Neither (never locks)
ML2030	Privacy (bedroom or bathroom, F19)	Restrooms, exam rooms	Inside thumbturn locks the outside grip
ML2051	Entrance or office (F04, toggle stop)	Offices, suite entrances	Outside, by key or toggle action stop
ML2054	Entrance or office (F04, thumbturn)	Offices, suite entrances	Outside, by inside thumbturn or key
ML2052	Classroom intruder (F32)	Classrooms	Outside or inside, by key from either side
ML2055	Classroom (F05)	Classrooms, conference rooms	Outside, by key
ML2057	Storeroom (F07)	Mechanical rooms, stockrooms, IT closets	Outside always locked, key retracts
ML2070	Full dummy trim	Pull-only side of a door	None, grips act as pulls

Three details that cause wrong orders. The ML2051 uses a toggle action stop on the outside grip, so it locks without a thumbturn. The ML2054 is the same F04 function with a thumbturn, which is the version most buyers actually want for an office. The ML2052 differs from the ML2055 only in that the inside can be keyed to lock the outside grip, which is what schools mean by "intruder" function. The ML2051 NSN entrance or office mortise lock is about $955. For how the ML2000 stacks against other mortise bodies read Schlage L9000 vs Sargent 8200 vs Corbin ML2000.

How do I read the trim codes: NSN, NSA, LWM, LSA, CSA?

The last letters of an ML2000 part number describe trim, not function. On the live NLS listings, NSA reads as NS lever on an A rose, CSA as CS lever on an A rose, and LWM as LW lever on an M escutcheon. LSA and NSN follow the same pattern: lever style first, rose or escutcheon style last. The finish code follows (626 satin chrome, 605 bright brass, 612 satin bronze, 613 oil rubbed bronze and so on, per the BHMA finish chart).

The practical rule: a function number gives you the lock case, a trim code gives you the outside appearance, and the two are independent. A buyer replacing a failed ML2055 in a school can keep the existing NSA trim and order only the case if the trim is intact. The ML2010 passage lock is sold both as a complete NSN passage lock and as an ML2010 LL body only, where armor and strike are included but trim is not. Check which one you are ordering before you check price.

Cylinders on a standard ML2000 are 6-pin brass in the L4 keyway, two nickel silver keys included. For matching key blanks see the commercial key blanks by brand guide,.

What is the ML20906 and what does it need to run?

The ML20906 is the electrified ML2000: an ML2000 mortise case with an electric solenoid that controls the outside grip. The version sold at NLS, the ML20906 NSA SEC fail secure mortise lock, is the SEC function with outside cylinder override. The behavior is fixed by the function:

• Power off: the outside grip is locked and a key retracts the latchbolt from outside.
• Power on: the outside grip works and the latchbolt retracts by grip from either side.
• Inside grip is always free, so egress never depends on power.
• The auxiliary latch deadlocks the latchbolt.

Electrical requirements from the product page: 12/24VDC, 15mA continuous, 0.5A peak draw, with an operating voltage tolerance of plus or minus 10%. The page limits you to two locks per 1A power supply, which sets your power budget on a multi-door job: size the supply by peak draw, not continuous draw. The M92 option adds a request-to-exit monitor (an SPDT switch rated 2 amp at 24VDC) that reports when the trim is activated, and both levers activate it.

The ML20906 is not interchangeable with a fail safe lock. If the opening requires the door to unlock on power loss (some stair reentry and life safety conditions), you need a different electrified function, and the logic for that choice is in fail safe vs fail secure for every electrified device.

Which ED exit device do I need: ED5200, ED5200A or ED4200?

All three are rim devices with a 3/4" stainless steel pullman latchbolt, 3-1/4" projection (2-3/4" dogged), single-point quarter turn hex key dogging as standard on panic devices, and a surface mounted 3/8" roller strike. The choice comes down to stile width and fire rating. The ED5200 needs a 4-1/2" minimum stile and meets ANSI A156.3 Type 1, Grade 1. The ED4200 drops the minimum stile to 2" and is listed to A156.3 Type 4, Grade 1. The ED5200A is the fire rated ED5200 and ships with sex nuts and bolts. Mechanical dogging is not available on fire rated devices.

Family	Model	Opening it fits	Electrified or option codes
ED5200	ED5200 rim exit device	36" bar for 30"-36" doors; stile 4-1/2" min	MELR, M92, M97 electric dogging, M51 less dogging, M52 cylinder dogging
ED5200	ED5200 W048	48" bar for 36"-48" doors	Same options as above
ED5200A	ED5200A fire rated	36" bar (W048 for 48"), 4-1/2" min stile	No mechanical dogging; fire rated
ED4200	ED4200 narrow stile	36" bar (W048 for 48"), 2" min stile	M97, M51, M52, M54 sex nuts and bolts
ED5200 MELR	Motorized latch retraction	Same as ED5200	Remote latch retraction; M92 adds touchbar monitoring
DC3200/DC3210	See closer section	Size 1 to 6, up to 180 degrees	Not electrified

The ED5200 is about $1,469 at NLS, and the W048 build is a separate line item, not an option on the standard part number. Bar length is field cut, so a 36" bar covers 30" to 36" doors and you only specify W048 for wider leaves. The device is non-handed, the lever trim is handed, so state the hand when you order trim. The ED5200 MELR gives remote-controlled motorized latch retraction for controlled openings; the M92 version adds touchbar monitoring. Dogging options (M51 less dogging, M52 cylinder dogging, M97 electric dogging) must be set when you order, not retrofitted from memory.

Do not use this section to decide between rim, SVR, CVR and mortise exit devices. That is a channel question covered in exit device types: rim vs SVR vs mortise vs CVR. Browse the full range on the ED5000 series exit devices category page.

Which Corbin Russwin closer matches the door: DC3000, DC3200, DC3210 or DC6200?

The DC3000 family is Grade 1 with a cast iron case, a 1-3/8" piston, adjustable spring size 1 to 6, and a 15-year limited warranty. Non-fire interior doors meet the ADA 5 lbf opening force limit when sized correctly, and the closers open to a full 180 degrees where the door and mounting allow. Valves for latching speed, closing speed and backcheck are standard. The delayed action valve is the M71 option (preset to 20 seconds between 90 and 70 degrees).

• DC3200 is the regular double lever arm closer with a full cover; the DC3200 689 M54 is about $384 at NLS, in aluminum painted finish.
• DC3210 adds the PA bracket and tri-mount (regular, top jamb or parallel arm). The DC3210 A1 is the friction hold open arm version, for doors that should stay open without a separate holder.
• DC6200 is the heavier line with a 25-year limited warranty and a crowned gear set on the spindle for added efficiency.

M54 in a closer part number means sex nuts and bolts instead of self-drilling screws, which matters on hollow metal and aluminum where screws strip. M75 adds a corrosion resistant coating for harsh environments. Size the spring against the door width as on any closer. Order from the DC3000 series page.

What is the 8000-7 core and what keying parts go with it?

The 8000-7 is a 7-pin large format interchangeable core (LFIC) in the L4 keyway, shipped 0 bitted with two keys and a blank. It is priced at about $78 at NLS. A "6-pin" Corbin Russwin part (the standard ML2000 cylinder, key blanks marked 6-pin) belongs to a conventional cylinder, not to the 8000-7. Mixing the two is the single most common return on this brand: a 7-pin core will not be operated by a 6-pin key.

Two practical points. The 8000-7 is available in finishes 626, 613, 605, 606, 612 and 625. Key blank sourcing for existing systems is in the key blanks guide linked above. If you also run Sargent, the Sargent hardware series guide decodes that family in the same format.

Common mistakes

1. Ordering by function number only. ML2051 without a trim code and finish is not a complete part. Always write series, function, trim, finish.
2. Confusing ML2051 and ML2054. Both are F04, but one locks by toggle action stop and the other by thumbturn. Match what is on the door today.
3. Ordering ED5200 for a narrow stile door. The ED5200 needs a 4-1/2" stile. A 2" aluminum stile needs the ED4200.
4. Forgetting W048. A 36" bar does not fit a 48" leaf. Specify W048 for 36"-48" doors.
5. Specifying mechanical dogging on a fire rated device. It is not available on the ED5200A.
6. Treating ML20906 as fail safe. It is fail secure: locked with power off, key from outside.
7. Mixing 6-pin blanks with the 7-pin 8000-7 core. The pin count must match end to end.
8. Power supply by continuous draw. The ML20906 peaks at 0.5A, so a 1A supply carries two locks, not more.

FAQ

What is the difference between ML2051 and ML2054? Both are the entrance or office F04 function. The ML2051 locks the outside grip with a toggle action stop, while the ML2054 uses an inside thumbturn. The latchbolt is retracted by the inside grip at all times on both.

Is the ED5200 fire rated? The standard ED5200 is a panic rated rim device, ANSI A156.3 Type 1 Grade 1. The fire rated version is the ED5200A, which ships with sex nuts and bolts and does not offer mechanical dogging.

Can one 1A power supply run several ML20906 locks? The product page limits it to two locks per 1A power supply, based on 0.5A peak draw each. The operating voltage must stay within plus or minus 10% of the 12 or 24VDC rating.

What does M54 mean on a DC3200 or DC3210? M54 is the option for sex nuts and bolts in place of self-drilling screws. It is the standard choice on hollow metal and aluminum doors where screws can strip.

Next step

Send the model number, trim code, finish and door details to the quote desk at get a quote and we will confirm the exact part before it ships. Agencies and municipalities can submit purchase orders through submit a gov PO. For stock questions call 718-814-6300. Orders placed before 3:00 p.m. EST ship same day, and ground shipping is free on orders of $450 and up.