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Baldwin 8540 Privacy Knob x Knob 2-1/2" Backset Mortise Lock Body
FEATURES
- For Knob by Knob
- Quick and easy install on pre-prepared doors
- Completely reversible for all door conditions. May be installed in either position.
- Turn Pieces and Emergency Release Trim must be ordered separately (NOT included in price of lock)
- Due to 2-1/4 in. spacing, not all Baldwin rosettes and ER trim will fit
- To verify fit, add 1/2 height of rose and 1/2 height of ER trim, total cannot exceed 2-1/4 in.
- Heavy gauge steel case, solid forged brass interior working parts.
- Dimensions: 0.625" x 3.375" x 3.75"
- Front: 0.156" x 1" x 5.75" Adjustable for beveled conditions. Finished to match.
- Latch Bolt: 0.5" x 0.625" x 0.5" throw. Furnished in US4 and 26D finishes to match trim.
- Dead Bolt: 0.5" x 0.625" x 0.5" throw. Furnished in US4 and 26D finishes to match trim.
- Hub Size: 0.29" Broached on the diamond.
- Backset: 2-1/2"
- Spacing: Knob hub to turn piece 2.25"
- Strike: Specially-designed curved lip strike is fully reversible (non-handed)
- Dust Box: Box is furnished unattached. Conceals installation marks and cutouts (8530-000)
- Packed one in a box with a strike, dust box, fasteners, and 3.5" spindle.
FEATURES
- Perfectly blending a mix of traditional and modern creates a cohesive transitional style, embodied within the design of this item.
- Dependability, quality, and high design. Baldwin's Quick Ship items are ready to ship to you within 5 business days from ordering.
Manufacturer Resources
Baldwin 2025 Cabinet Hardware Lookbook
Product Specs
- Product Group:
- Mechanical Locks
- Product Type:
- Knob Handle
- Subcategory:
- Mechanical Locks
- Product Subgroup:
- Bored Locksets
- Commercial/Residential:
- Residential
- Knob Diameter:
- 2.37"
- Maximum Door Thickness:
- 1.75"
- Minimum Door Thickness:
- 1.37"
- Product Attribute:
- Cylindrical Locks
- Product Model:
- 8540
- Product Function:
- Privacy/Bed/Bath
- Product Style:
- Transitional
- Product Category:
- Mechanical Locks
- Department:
- Door Hardware
Baldwin 8540031L – Frequently Asked Questions
1) Does the Baldwin 8540 privacy mortise lock come with the knobs and turn pieces, or is it just the lock body?
Just the mechanism. The 8540 is a privacy mortise lock body, packed one to a box with a strike, dust box, fasteners, and a 3.5 inch spindle. Turn pieces and the emergency release trim are separate orders, and so are the knobs themselves. Budget for the lock body plus the knob and rose set plus the turn piece and ER trim to finish one door.
2) Will all Baldwin rosettes and emergency release trim fit the 8540 mortise lock?
No, and this is the detail that trips up most orders. The 8540 has 2-1/4 inch spacing from the knob hub to the turn piece, which is tight. To check any combination, add half the height of the rose to half the height of the ER trim; if that total is over 2-1/4 inches, the two will collide and the pair will not work. Do the arithmetic before you commit to a trim style.
3) What door thickness does the Baldwin 8540 privacy lock fit?
Doors from 1.37 to 1.75 inches thick. That covers both the standard 1-3/4 inch door and the lighter 1-3/8 inch interior door found in older houses, so it drops into typical bed and bath openings either way. It ships with a 3.5 inch spindle to suit that range.
4) Do I need to know the handing before ordering the Baldwin 8540 lock body?
You pick left hand interior or right hand interior at order time, but the lock itself is fully reversible and can be installed in either position for any door condition. The strike is a curved lip design and is non-handed. So a handing mistake on the order is recoverable in the field rather than a return.
5) What backset is the Baldwin 8540, and can I get it in 2-3/8 or 2-3/4?
The 8540 is a 2-1/2 inch backset only. That is not one of the two usual bored-lock backsets of 2-3/8 and 2-3/4, so the door has to be mortised for 2-1/2 or you are cutting new prep. Measure from the door edge to the center of the knob hub on the existing prep before ordering.
6) Is the Baldwin 8540 a keyed lock or a bathroom privacy function?
Privacy function, for bed and bath. It locks from the inside with a turn piece and releases from the outside with emergency release trim, both ordered separately. There is no cylinder and no key. If you need a keyed opening, this is the wrong function to specify.
7) Will the Baldwin 8540 latch into the strike already in my jamb?
Plan on using the strike that comes with it. Both the latch bolt and the dead bolt throw 0.5 inch, and the lock ships with a specially designed curved lip strike sized to that throw. An existing cylindrical lock strike is cut for a different case and lip geometry, so reusing it usually means the door does not pull up tight or the deadbolt does not seat.
8) What size mortise pocket does the Baldwin 8540 lock case need?
The case measures 0.625 x 3.375 x 3.75 inches and the front is 0.156 x 1 x 5.75 inches. The front is adjustable for beveled door conditions and is finished to match the trim. A dust box (8530-000) comes unattached in the box to line the pocket and hide the cutout marks.
9) Is the Baldwin 8540 mortise lock rated for a commercial building or apartment corridor doors?
It is a residential-duty lock. Baldwin lists the 8540 as residential, which puts it in single family homes, condos, and the unit interiors of multi family rather than a high traffic commercial opening. The case is heavy gauge steel with solid forged brass working parts, but for a common area or corridor door specify a commercial grade lock instead.
10) Will the Baldwin 8540 accept a lever instead of a knob?
No. The 8540 is built for knob by knob, and the hub is 0.29 inch broached on the diamond to suit knob trim. For a lever opening you need the lever version of the mortise body, not this one.
11) Can I match the Baldwin 8540 to the brass and nickel hardware already on my other doors?
Nine finishes are offered: 003 Lifetime Brass, 031 Non-Lacquered Brass, 033 Vintage Brass, 044 Satin Brass, 050 Antique Brass, 055 Lifetime Bright Nickel, 056 Lifetime Satin Nickel, 060 Satin Brass and Brown, and 076 Graphite Nickel. Each is available in both left and right hand interior. Note that the latch bolt, dead bolt, and strike come in US4 and 26D finishes to match trim rather than in the full finish range, and the front is finished to match.
12) How big are the knobs that go on a Baldwin 8540 mortise lock, and will they clear a door casing?
Knob diameter is 2.37 inches. With a 2-1/2 inch backset the knob center sits far enough off the door edge that a 2.37 inch knob clears trim on a normally cased opening, but check any door with heavy applied moulding tight to the edge.
How fast can I get the Baldwin 8540031L delivered?
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reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Baldwin 8540031L come with a warranty?
Absolutely. The Baldwin 8540031L is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
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