SAME DAY & EXPEDITED SHIPPING AVAILABLE
Flushlocks
A flush lock sits inside the door stile with almost nothing projecting from the face, which is why it is used on the inactive leaf of paired doors and on sliding doors. Shop Adams Rite 1870 cylinder-operated flushbolts for aluminum doors, the 1870HM for hollow metal, the 1877 for wood, the MS1880 two-point flush bolt and flush locksets for sliding doors.
What is a flush lock?
A flush lock is a lock or bolt mortised into the edge or stile of a door so that its face is level with the door surface. In commercial hardware the term covers two products: cylinder-operated flushbolts, which lock the inactive leaf of a pair of doors with a key, and flush locksets, which lock sliding doors where a projecting lever or knob would hit the frame. All the flush locks in this category are made by Adams Rite.
Cylinder-operated flushbolts for paired doors
A cylinder-operated flushbolt replaces the usual flip-lever flushbolt on the inactive leaf of a pair of doors, so only someone with a key can lock or release that leaf. Adams Rite describes the 1870 as designed for greater key control and to prevent accidental locking of the inactive leaf on narrow stile aluminum paired doors, and it can be installed to lock at the threshold or at the header. The cylinder is sold separately, and it takes a mortise cylinder. Versions in the catalog:
- 1870: flat faceplate, non-handed, for narrow stile aluminum doors.
- 1871: radius faceplate, 1-1/8" backset, non-handed.
- 1870HM: flat faceplate, for hollow metal doors.
- 1877: 1-1/4" backset and 31" cylinder height, for wood doors.
Two-point flush bolts: the MS1880
The Adams Rite MS1880 two-point flush bolt locks the inactive leaf at the top and bottom with one turn. Adams Rite positions it as a more convenient alternative to flip-lever flushbolts: one operation secures the leaf and reduces human error. The MS1880-03 in the catalog has an hourglass-shaped turn and a cylinder height of 39-1/16" to 43".
Flush locksets for sliding doors
A flush lockset for a sliding door combines a narrow stile deadlock with a slide button, so nothing sticks out to catch on the frame when the door slides open. The 4189 and 4190 are all-metal flush locksets that, according to the listing, project only 1/10" from the stile on either side and use the Adams Rite MS1847 deadlock. The 4430 and 4431 are similar in function and size, with a radius or square lock face and a 1" to 1-5/16" stile thickness.
| Adams Rite model | Type | Door type or fit | Notes from the listing |
|---|---|---|---|
| 1870 | Cylinder-operated flushbolt | Narrow stile aluminum, pairs | Flat faceplate, non-handed, cylinder sold separately |
| 1871 | Cylinder-operated flushbolt | Narrow stile aluminum, pairs | Radius faceplate, 1-1/8" backset, non-handed |
| 1870HM | Cylinder-operated flushbolt | Hollow metal, pairs | Flat faceplate |
| 1877 | Cylinder-operated flushbolt | Wood, pairs | 1-1/4" backset, 31" cylinder height |
| MS1880-03 | Two-point flush bolt | Inactive leaf of pairs | Hourglass turn, 39-1/16" to 43" cylinder height |
| 4189 / 4190 | Flush lockset | Sliding doors | MS1847 deadlock with slide button; 4189 without cylinder, 4190 with cylinder |
| 4430 / 4431 | Flush lockset | Sliding doors, 1" to 1-5/16" stile | 4430 radius face without cylinder; 4431 square face with cylinder, keyed different |
Choosing between a flushbolt and a flush lockset
Choose a cylinder-operated flushbolt when the problem is the inactive leaf of a pair of swinging doors, and a flush lockset when the door slides. On swinging pairs, the active leaf keeps its own deadlock or exit device, and the flushbolt holds the inactive leaf in place. Check local egress requirements before locking the inactive leaf of a pair on an exit route, because some codes limit manual flush bolts on exits.
Cylinders for flush locks
Most Adams Rite flushbolts in this category are sold without a cylinder, so order a mortise cylinder with an Adams Rite cam in your keyway. The 4190 and 4431 flush locksets come with a cylinder and are listed as keyed different, while the 4189 and 4430 are without cylinder. See mortise cylinders to match your key system.
Most requested flush locks
The flush locks our customers look up most often right now:
- Adams Rite 4189 Flush Lockset without Cylinder, for sliding doors
- Adams Rite 4431 Flush Lockset with Cylinder, Square Lock Face
- Adams Rite MS1880-03 Two-Point Flush Bolt
- Adams Rite 4190 Flush Lockset with Cylinder
- Adams Rite 1877 Cylinder-Operated Flush Bolt for wood doors
Shop by model: 1870 cylinder-operated flushbolts and 1870HM.
Related categories: storefront bolts and latches, deadlatches, Adams Rite accessories and flush bolts and coordinators.
What to have ready when ordering a flush lock
- Door type: narrow stile aluminum, hollow metal or wood, and swinging or sliding.
- For flushbolts: faceplate (flat or radius), backset and cylinder height.
- For sliding door locksets: stile thickness and lock face (radius or square).
- With or without cylinder, the keyway and keyed alike or different.
- Finish to match the door and the existing hardware.
For more on Adams Rite storefront hardware, see our MS1850 vs MS1890 deadbolt guide.
Fitting out several storefronts? Request a quote, and schools and agencies can submit a government or school PO. Orders placed before 3:00 p.m. ET on business days ship the same day after card approval, and ground shipping is free on orders of $450+. Call 718-814-6300 to match a flush lock to your door.
The tables and selection notes on this page are compiled by National Lock Supply from the Adams Rite catalog and product listings. Last reviewed: November 2026.
Frequently Asked Questions
What are the best door locks for flush doors?
For a pair of flush swinging doors, a cylinder-operated flushbolt on the inactive leaf with a deadlock or exit device on the active leaf is a common setup. For flush sliding doors, a flush lockset such as the Adams Rite 4189, 4190, 4430 or 4431 avoids projecting hardware that would catch on the frame.
Which flush lock do I need for a wood door?
For paired wood doors, the Adams Rite 1877 cylinder-operated flush bolt is listed with a 1-1/4" backset and a 31" cylinder height, and it can lock at the threshold or the header. The 1870 and 1871 are for narrow stile aluminum doors and the 1870HM for hollow metal.
What is the difference between the 4189 and 4190 flush locksets?
Both are Adams Rite flush locksets for sliding doors that combine the MS1847 deadlock with a slide button. The 4189 is supplied without a cylinder and the 4190 with a cylinder, keyed different. Their listings note they project only 1/10" from the stile on either side.
Can I lock the inactive leaf of an exit pair with a flush bolt?
It depends on the code and the door's use. Many codes limit manual flush bolts on doors that are part of an exit route, and some allow them only in certain occupancies. Check with your code official before adding a flush bolt to a pair that serves as an exit.