Deltana 178MST Mortise Strike, 1-7/8" x 1-1/16", Solid Brass

It has to be mortised. The 178MST is a mortise strike, so you rout a pocket the size of the plate, 1-7/8 by 1-1/16 inches, and the plate sits flush. There is no surface mount version of it. If you are working a threshold or a floor where you cannot cut a clean pocket, a mortise strike is the wrong choice for that location.

Measure the existing pocket, not the old plate. The 178MST needs a clean 1-7/8 by 1-1/16 inch opening; if your current strike is smaller, you can enlarge the mortise, but if it is larger you will have a gap around the plate. On a retrofit where the old cutout is oversized, an adjustable-type strike such as the Kwikset 80318 full round adjustable strike covers a wider range of prep, though that one is a deadbolt strike rather than a surface bolt strike.

No. The Deltana 178MST is a mortise strike made for use with surface bolts, and it mortises into the frame or sill at 1-7/8 inch by 1-1/16 inch. Deadbolt strike plates such as the Emtek 83223 Standard Deadbolt Strike Plate with square corners and the Kwikset 80318 Full Round Adjustable Strike are built for the throw of a deadbolt latch, not for the round rod of a surface bolt, and their prep and hole geometry follow the deadbolt bore. If the bolt going into the opening is a surface bolt, the 178MST is the strike that matches it.

No. An ASA-prepped frame takes an ASA-format strike such as the Codelocks ASA Strike Plate in stainless steel finish, which is cut to that standard opening. The Deltana 178MST is a 1-7/8 inch by 1-1/16 inch mortise strike for surface bolts, and neither the size nor the function suits a deadbolt in an ASA cutout. Keep the 178MST for the surface bolts at the head and sill and use the ASA strike where the frame is prepped for it.

Nine finishes: polished brass, PVD polished brass, antique brass, oil rubbed bronze, brushed nickel, antique nickel, polished chrome, brushed chrome, and paint black. If you are matching surface bolts already on the doors, the PVD polished brass is the plated version that resists tarnish, while standard polished brass is the lacquered brass finish.

Solid brass, both the material and the substrate. That matters on exterior pairs and on coastal jobs where a plated steel strike rusts out in the pocket and stains the frame around it. Brass also lets you dress the opening slightly with a file if the bolt is riding a touch high.

The 178MST is the strike plate itself, cut from solid brass at 1-7/8 by 1-1/16 inches. If you want a lined pocket so the bolt does not pick up debris or chew into the frame, a separate strike box is the part to add, for example the Kwikset 81231-001 metal strike dust box or the Kwikset 81640 strike box.

No handing. The 178MST is a symmetrical rectangular mortise strike at 1-7/8 by 1-1/16 inches, so the same part works on a left hand or right hand leaf, and at the head or the sill. Order by finish only.

Different jobs entirely. The 178MST is a small solid brass mortise strike, 1-7/8 by 1-1/16 inches, that catches a surface bolt. An ASA strike, like the Codelocks ASA strike plate in stainless steel, is the tall standard-prep lip strike that receives a latchbolt from a lockset or a code lock in a metal frame. If your frame is already prepped ASA, the 178MST is not what drops into it.

They do two different jobs and are often used together. The Deltana 178MST is the visible face plate, mortised flush into the frame or sill at 1-7/8 inch by 1-1/16 inch in solid brass, and it is what the surface bolt rod enters. The Kwikset 81640 Strike Box and the Kwikset 81231-001 Metal Strike Dust Box are the cup that sits behind a strike plate to line the bored hole and catch debris. Ordering a strike box when you need the finished face plate leaves the opening without the part the bolt actually lands on.

The Deltana 178MST is a fixed mortise strike at 1-7/8 inch by 1-1/16 inch, so the mortise has to be cut where the surface bolt lands. Where the misalignment is on a latch or deadbolt rather than a surface bolt, the Kwikset 80318 Full Round Adjustable Strike and the Kwikset 81825 6 Way Adjustable Deadlatch are the adjustable options in the group, both of them deadbolt strike plates. For a surface bolt opening, the correction is made in the mortise layout, not in the strike.

The Deltana 178MST is solid brass and comes in PVD Polished Brass, Polished Brass, Antique Brass, Oil Rubbed Bronze, Brushed Nickel, Antique Nickel, Polished Chrome, Brushed Chrome, and Paint Black, so it can be matched to existing decorative hardware across a building. The Codelocks ASA Strike Plate comes in a stainless steel finish and is an ASA-format strike, a different shape and prep intended for the ASA cutout in a commercial frame. For a surface bolt on a finished door where appearance matters, the 178MST is the one that carries the finish range.

Deltana lists the 178MST as commercial. In practice that puts it on multi-family entry pairs, office double doors, and any inactive leaf that gets bolted daily, not just on a residential French door. The solid brass body is what carries that duty.