Deltana SPDP278 Dust Proof Strike, Adjustable, 2-7/8" x 1-3/8", Solid Brass

A dust proof strike is the floor-mounted receiver that catches the bottom bolt on a pair of doors: the flush bolt or vertical rod drops into it, and a spring-loaded plunger inside keeps dirt, grit and debris from packing the hole so the bolt still seats. The Deltana SPDP278 is the adjustable version, made of solid brass, and it mounts into the floor or threshold under the inactive leaf. If your bottom bolt is hitting a clogged hole or dropping onto bare concrete, this is the part that fixes it.

Two alternatives cover most situations. The Trimco 3911 Series is the other adjustable dust proof strike, and it is the one to look at when the job spec calls out Trimco or when you are matching other Trimco trim already in the building. The Detex 96B Strike Kit is a different animal: it is sold as the bottom strike for Detex 50 Series surface vertical rod exit devices, so reach for it when that is the device on the door, not as a general floor strike. If you want solid brass and a finish that matches decorative door trim, the Deltana is the one that offers it across eight finishes.

The SPDP278 measures 3-1/2 x 1-5/8 inches. Lay those numbers against the existing plate before you pull it: if the old strike's plate is the same or smaller, the Deltana covers the hole. If the strike coming out is larger, you will see the old mortise around the edges and need to patch or fill.

Only if the device manufacturer does not require its own strike. The Detex 96B Strike Kit is a bottom dust proof strike built specifically for Detex 50 Series surface vertical rod exit devices, and on those openings it is the part the device is designed around. The Deltana SPDP278 is a general-purpose adjustable dust proof strike in solid brass, sized 3-1/2 inch by 1-5/8 inch, intended for flush bolts and manual bottom bolts on commercial openings. On a 50 Series Detex device, order the 96B kit; on a pair of doors with conventional flush bolts, the SPDP278 is the right part.

Commercial is what it is built for, and the body is solid brass rather than plated pot metal, which is the reason it holds up in a doorway that gets kicked and mopped daily. Property managers standardizing across a building can use the same strike on interior office pairs and on higher-traffic corridor pairs.

A drilled hole in a concrete slab fills with grit within weeks, and once it does the bottom bolt stops seating, which means the inactive leaf is no longer holding. That is the whole reason the dust proof strike exists: the spring plunger rides up under the plunger's return and pushes debris out when the bolt lifts. On any pair of doors where the inactive leaf carries the strike for the active latch, skipping the floor strike puts the whole opening out of service the first time someone mops.

Both are adjustable dust proof strikes and either can be run fleet-wide across conventional flush bolt openings. The deciding factor is usually finish continuity: the Deltana SPDP278 is solid brass and is stocked in eight finishes, including Oil Rubbed Bronze, Brushed Nickel, Antique Nickel, Polished Chrome, Brushed Chrome, Polished Brass, PVD Polished Brass, and Antique Brass, so it can be matched to whatever lever and hinge finish is already on the doors. The Trimco 3911 Series covers the same adjustable dust proof strike function. Where an opening carries a Detex 50 Series surface vertical rod device, that opening takes the Detex 96B strike kit regardless of what the rest of the building standardizes on.

No. They look similar in the floor but they are not interchangeable. The Detex 96B is a strike kit matched to Detex 50 Series surface vertical rod exit devices and belongs to the Detex 90 Strike Series, so its prep and rod engagement follow that device line. The Deltana SPDP278 is an adjustable dust proof strike with a 3-1/2 inch by 1-5/8 inch faceplate in solid brass, used with standard flush bolts. Swapping one for the other means re-prepping the floor, so match the strike to what is actually driving the bolt.

One per bottom bolt. A standard pair with a single inactive leaf takes one strike in the floor under that leaf. If the opening uses top and bottom flush bolts, only the bottom bolt needs the floor strike; the top bolt strikes into the frame head. Sold each, so order per opening, not per pair.