Baldwin 8550 Single Cylinder 2...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$312.00
$201.80
Baldwin 8550 Single Cylinder 2-1/2" Backset Mortise Deadlock Body

Baldwin 8550 Single Cylinder 2-1/2" Backset Mortise Deadlock Body

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Model: 8550190
From the Estate Series Collection
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$312.00
$201.80
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Baldwin 8550 Single Cylinder 2-1/2" Backset Mortise Deadlock Body

The Baldwin 8550 Single Cylinder 2-1/2” Backset Mortise Deadlock Body is a high-quality mortise lock component designed for secure and dependable door locking performance in residential and commercial applications. Built with Baldwin’s trusted craftsmanship, this mortise deadlock body provides strong deadbolt security and is ideal for replacement, upgrades, or new door hardware installations.

Featuring a 2-1/2 inch backset, the Baldwin 8550 is designed for mortise lock preparations requiring a durable, heavy-duty deadlocking solution with smooth operation and long-lasting reliability.

Key Features & Benefits

  • Single cylinder mortise deadlock body for secure locking applications
  • 2-1/2” backset for standard mortise door preparations
  • Heavy-duty construction for long-term durability
  • Ideal for replacement or new mortise lock installations
  • Trusted Baldwin quality for premium door security solutions
  • Designed for smooth deadbolt engagement and reliable performance

Specifications

  • Brand: Baldwin
  • Model: 8550
  • Product Type: Mortise Deadlock Body
  • Function: Single Cylinder Deadlock
  • Backset: 2-1/2 inches
  • Application: Mortise lock door hardware systems
  • Use Location: Residential and Commercial Doors
  • Cylinder: Single cylinder (cylinder sold separately if not included)

Product Specs

Product Group:
Mechanical Locks
Product Type:
Mortise Locks
Subcategory:
Mortise Locks
Product Subgroup:
Mortise Locks
Commercial/Residential:
Residential
Collection:
Estate Series
Lock Function:
Deadlock
Latch Faceplate Dimension:
1" x 5-3/4"
Product Model:
8550
Product Function:
Deadlock
Door Thickness Range:
1-3/8" and Over
Door Strike:
ASA Strike
Product Substrate:
Brass / Steel
Product Category:
Mechanical Locks
Backset (Distance):
2-1/2"
Department:
Door Hardware

Baldwin 8550190 – Frequently Asked Questions

1) Will the Baldwin 8550 mortise deadlock fit a 2-1/2 inch backset mortise pocket?
That is exactly what the 8550 is cut for. It's a 2-1/2 inch backset deadlock body, so the cylinder hole in the door has to sit 2-1/2 inches back from the door edge. Most commercial mortise prep is 2-3/4 inch, so if you're pulling out an existing lock, measure from the edge of the door to the center of the cylinder before you order. A 2-3/4 inch pocket will not line up with this body without re-prepping the door.
2) Does the Baldwin 8550 come with a cylinder, or do I order that separately?
The 8550 is a lock body only. It's a single cylinder deadlock, meaning key on the outside and a turn piece inside, and the cylinder is a separate order line if it isn't included with your set. Budget for the cylinder, the keying, and the exterior and interior trim when you spec the job.
3) Do I need to order the Baldwin 8550 handed left or right?
No handing to specify. The 8550 body is reversible in both finishes offered, so the same part works on a left hand or right hand door. A deadbolt has no latch bevel to flip, which is why handing drops out of the order.
4) Should I use a mortise deadlock body or a full mortise lockset with a handle?
A deadlock body like the 8550 does one job: throw a bolt. There's no latch and no lever or knob operation, so the door needs a separate handle or a pull, and it won't self-latch when it closes. If you want the handle and the locking in one pocket, a full mortise lockset is the answer, for example the Corbin Russwin ML2003 classroom lockset or the Cal-Royal NM8050 entrance/office lockset. Pick the deadlock body when the door already has its handleset and you only need the bolt.
5) Is the Baldwin 8550 mortise deadlock suitable for a commercial building?
Baldwin lists the 8550 as a residential product, part of its Estate Series. It's a brass and steel body built for high-end homes and light-duty openings. For a school corridor, an office suite, or anything with real traffic and a code inspector attached, go to a Grade 1 mortise product instead, such as the Sargent 4874 double cylinder mortise deadbolt or the Cal-Royal NM8080 Grade 1 storeroom lockset.
6) I need a keyed mortise deadbolt but the door is keyed on both sides - what replaces the Baldwin 8550?
Use the Sargent 4874, a double cylinder mortise deadbolt with a 2-3/4 inch backset. It takes a cylinder on each face, so the interior side is keyed rather than thumbturn-operated. The Baldwin 8550 is a single cylinder deadlock, so it will not give you a keyed inside face. Confirm the door's existing mortise backset before ordering - the Baldwin 8550 is 2-1/2 inch and the Sargent 4874 is 2-3/4 inch.
7) What is the closest equivalent to the Baldwin 8550 mortise deadlock body from another brand?
The Sargent 4874 mortise deadbolt is the nearest peer in intent - it is a mortise-prepped deadbolt body with no latch and no lever trim, like the Baldwin 8550 deadlock. Two differences decide the swap. The Sargent 4874 is a double cylinder deadbolt, keyed both sides, where the 8550 is a single cylinder deadlock. And the Sargent 4874 is a 2-3/4 inch backset against the 8550's 2-1/2 inch backset, so the cylinder hole and mortise pocket land at different distances from the door edge. If the door is already prepped for a 2-1/2 inch backset, the 4874 is not a drop-in.
8) The opening needs a latch and a lever, not just a deadbolt - what mortise lock should I use instead of the Baldwin 8550?
The Baldwin 8550 is a deadlock body: it throws a bolt and nothing else, so it needs a separate latch or a pull to work the door. For a single mortise case that gives both a keyed bolt and a latching lever, the Sargent 7925 is a Grade 1 heavy duty dormitory exit function mortise lock with rose trim and a single cylinder deadbolt. The Cal-Royal NM8440 is a Grade 1 privacy mortise lockset with deadbolt for a 1-3/4 inch door, if the room wants privacy rather than keyed control.
9) My facility spec calls for ANSI/BHMA Grade 1 on the mortise hardware - does the Baldwin 8550 fit, and what does if not?
The Baldwin 8550 is an Estate Series residential mortise deadlock body, so it is built for residential openings rather than a Grade 1 institutional line. Where the spec demands Grade 1 mortise hardware, the Accentra 8805FL is a Grade 1 storeroom mortise lock in the 8800 Series, the Cal-Royal NM8080 is a Grade 1 storeroom mortise lockset with an interchangeable core option for 1-3/4 inch doors, and the Corbin Russwin ML2003 is a Grade 1 mortise classroom lockset in the ML2000 Series for 1-3/4 inch doors.
10) Can I use the Baldwin 8550 to add a deadbolt above an existing mortise lockset on an old door?
Yes, that's a common use for a separate deadlock body, and it's what the 8550 is for. The door needs its own mortise pocket cut for the second body, with the cylinder hole at 2-1/2 inches back from the door edge and a 1 x 5-3/4 inch faceplate mortise in the edge. The frame needs an ASA strike prep opposite the bolt. On a 1-3/8 inch door or thicker there's enough material to do it.
11) Is the Kaba Ilco 185 a substitute for the Baldwin 8550 mortise deadlock?
Both are keyed bolt hardware without lever trim - the Kaba Ilco 185 Series is a deadbolt function mortise lock supplied with no handing, and the Baldwin 8550 is a single cylinder deadlock body whose finishes are offered reversible. They are not the same product family, though: the Baldwin 8550 is an Estate Series brass and steel body cut for a 2-1/2 inch backset with a 1 inch by 5-3/4 inch faceplate and an ASA strike. Match those three numbers against the existing door prep before treating the 185 Series as a swap.
12) Which mortise lock replaces the Baldwin 8550 if I want keypad or credential access instead of a key?
The Baldwin 8550 is a mechanical single cylinder deadlock body. For electronic control on a mortise prep, the Alarm Lock DL4500 Series is a Grade 1 electronic mortise deadbolt with 2,000 user codes and a privacy keypad for 1-5/8 inch to 1-7/8 inch doors - the closest match in function, since it is a deadbolt rather than a latching lockset. If the opening needs a lever as well, the Schlage CO-100 is a Grade 1 heavy duty standalone electronic mortise lock with a keypad reader for 1-3/4 inch doors, and the TownSteel FME-2000 Series is a Grade 1 heavy duty classroom mortise lockset with RFID for 1-3/4 inch doors.
13) Are the Sargent 130KB and 130W thumbturns alternatives to the Baldwin 8550?
No. The Sargent 130KB is a standard duty mortise thumbturn in the 8200 Series and the Sargent 130W is a standard duty mortise thumbturn with a round backplate in the 7800 Series - both are the turn piece that operates a bolt from the inside face, not the bolt mechanism itself. The Baldwin 8550 is the deadlock body that carries the bolt and takes the cylinder. A thumbturn does not lock a door on its own and does not fill a mortise pocket.
14) The door only needs to latch, not lock - is there a simpler mortise option than the Baldwin 8550?
Yes. The Baldwin 8550 is a keyed single cylinder deadlock and carries a cylinder. Where the opening only has to hold shut, the Schlage PM010 is a Grade 1 non-keyed passage latch mortise lock for 1-3/4 inch doors, the Falcon MA101 is a Grade 1 heavy duty mortise passage lock with field reversible operation and a fire rating, and the Hager 3810S is a 3800 Series Grade 1 passage mortise lock with rose and a 2-3/4 inch backset for 1-3/4 inch to 2-1/2 inch doors. None of the three takes a key.
15) Baldwin 8550 versus Cal-Royal NM8050 - which one suits a commercial entrance?
They solve different halves of the opening. The Cal-Royal NM8050 is a heavy duty Grade 1 office and entrance mortise lockset with an auxiliary deadlatch, sized for a 1-3/4 inch door, so it latches, secures and carries lever trim in one case. The Baldwin 8550 is an Estate Series residential deadlock body with a 2-1/2 inch backset and a 1 inch by 5-3/4 inch faceplate, providing bolt security only and relying on separate hardware to keep the door closed. For a keyed entrance handled by one case, the NM8050 covers it; for adding a bolt to a decorative Baldwin opening, the 8550 is the part.
16) Will a Baldwin 8550 work on a glass entry door or an aluminum stile door?
No. The Baldwin 8550 is a mortise deadlock body cut for a 2-1/2 inch backset in doors 1-3/8 inch and over, with an ASA strike - a wood or solid door prep. Narrow stile and glass openings take dedicated hardware: the Kaba Ilco BR Series is a glass door bottom rail lock, the Alarm Lock DL1300NW is a Trilogy Networx wireless electronic mortise lock with keypad built for Adams Rite deadlatches, and the Dormakaba E-Plex 2066 is a wide stile electronic pushbutton keyless mortise lock.
17) Can I use the Baldwin 8550 on a 1 inch thick ornamental iron door?
No - the Baldwin 8550 is built for doors 1-3/8 inch and over. For thin iron stiles, the Marks USA 21AC is an entrance double cylinder Unilock ornamental iron mortise lock with a round knob for 1 inch doors, and the Marks USA 22AC is an entrance double cylinder ornamental iron mortise lock with round knob, also for 1 inch doors.
18) The access control drawing calls for the mortise lock to be released electrically - does the Baldwin 8550 do that?
The Baldwin 8550 is a mechanical single cylinder deadlock with no electrical provision. For an electrified mortise case, the Command Access ML190 Series is a motorized mortise lock with field selectable fail safe and fail secure operation on 24VDC in a heavy duty storeroom function, the BEST 45HW Series is a wired electromechanical heavy duty mortise lock running 12V or 24V, and the Schlage L9092EU 03A is a heavy duty electric lock and unlock outside lever mortise lock, keyed outside, with request to exit on 12 or 24VDC for 1-3/4 inch doors.
19) Baldwin 8550 or a BEST 45H mortise lock body - which fits a high-traffic multi-family corridor?
The BEST 45H Series is a heavy duty mortise lock body with public entrance function and field reversible operation, and the BEST 45HCA Series is a heavy duty mortise lockbody with intruder function - both are lock bodies for high-use commercial openings. The Baldwin 8550 is an Estate Series residential deadlock body in brass and steel with a 2-1/2 inch backset. On a corridor that cycles constantly and needs a latching public entrance function, the 45H body is the one specified for it; the 8550 suits residential unit doors where a decorative Baldwin bolt is wanted.
20) What finishes does the Baldwin 8550 deadlock body come in?
Two: 031 non-lacquered brass, which is a living finish that will darken and patina over time, and 190 satin black. The body sits inside the door, so the finish mostly matters for the exposed faceplate on the door edge, and it should be matched to the trim and the cylinder collar you're pairing it with.
21) What is the Baldwin 8550 made of and will it hold up on an exterior door?
Brass and steel construction. Brass handles the exposed faceplate and the corrosion exposure on an entry door, steel does the working parts inside the case. Baldwin positions it as an Estate Series residential product, so it suits a house or a townhome entry rather than a high-cycle commercial opening.
22) I am matching decorative Baldwin mortise hardware on an inactive door - is an Emtek mortise entrance set the right pick?
For a door leaf that never operates, yes - the Emtek 3019 Brisbane, 3102 Memphis, 3104 Hamilton and 3106 Manhattan are all dummy function mortise entrance locksets, meaning the trim mounts for appearance and there is no working bolt behind it. The Baldwin 8550 is the opposite case: a deadlock body with a working single cylinder bolt, in Estate Series brass and steel, offered in 031 non-lacquered brass and 190 satin black. Use the dummy sets on the fixed leaf and the 8550 on the leaf that has to lock.
23) Is a Schlage L0170 half dummy trim an alternative to the Baldwin 8550?
No. The Schlage L0170 is a Grade 1 heavy duty half dummy trim, a non-keyed lever with no mechanism behind it, for 1-3/4 inch doors. The Baldwin 8550 is a working single cylinder deadlock body that throws a bolt into an ASA strike. The L0170 mounts on the face of the door and does not require the deadlock pocket the 8550 sits in.
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Does the Baldwin 8550190 come with a warranty?
Absolutely. The Baldwin 8550190 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
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