Deltana SCMS905 Machine Screw, Steel, #9 x 1/2"

It is a #9 x 1/2 inch machine screw in steel. The #9 refers to the diameter gauge and the 1/2 inch is the length, so it is a short fastener meant for attaching trim and hardware plates rather than anchoring into framing.

Eight finishes: oil rubbed bronze, brushed nickel, polished chrome, brushed chrome, polished brass, brushed brass, antique brass, and prime coat white. That range exists so the screw head disappears into the escutcheon, hinge or door trim it is holding, instead of showing a bare steel head against a finished plate. Prime coat white is the one to pick if the screw head will be painted with the door or casing.

A machine screw like the SCMS905 has a uniform straight thread and is meant to thread into a tapped hole or a mating nut, typically in a metal part of the hardware itself. It will not bite into bare wood or drywall the way a tapered wood screw does. If you are fastening through a plate into a wood door or jamb with no threaded receiver, you want a wood screw instead; if you are threading into the tapped boss of a knob rose, escutcheon, or similar door trim, the machine screw is correct.

At 1/2 inch of length, the SCMS905 covers thin stack-ups only: a rose, plate, or escutcheon threading into a tapped post right behind it. It will not reach through a 1-3/4 inch door or through a plate plus a thick spacer. Measure the total thickness of everything the screw has to pass through plus the depth of thread engagement you need, and step up in length if that total exceeds 1/2 inch.

Each. The unit of measure is a single screw, so if you are replacing a set of four on an escutcheon or doing a whole floor of units, order the count you actually need rather than assuming a box quantity.

Deltana lists the SCMS905 as a residential item. It is a finish fastener for door trim and accessories, so it suits apartments, single family and light multi-family work. For high-traffic commercial openings, spec the fastener the device manufacturer supplies with the hardware.

Steel, both material and substrate, with the finish applied over it. That matters for two reasons: it is stronger than a solid brass screw of the same size and less prone to a stripped head on install, but a plated steel screw in an exterior or wet location will eventually corrode where brass would not. For interior door trim it is the usual choice.

The SCMS905 is offered in eight finishes across the brass, chrome, nickel and bronze families, plus a prime coat white for painted trim. If your portfolio runs a mix of oil rubbed bronze and brushed nickel hardware, you can stock the same #9 x 1/2 inch steel screw in both and keep one part number and two finishes on the shelf rather than sourcing per building.