Metallics TRM89M 8-32 x 2 in. Round Head Tri-Drive Machine Screws - Steel Zinc - Each

Any of three. The TRM89M has a round head with a combination slotted, Phillips, and square drive recess, so a flat blade, a Phillips bit, or a square (Robertson) bit all engage it. That is useful on a ladder when you only have one bit in the gun, and it keeps the same screw usable across crews carrying different drivers.

Yes. 8-32 is the standard thread used for outlet boxes, device mounting ears, plaster rings, and cover plates in US electrical work, and the TRM89M is an 8-32 machine screw. The 2 inch length is the long one you reach for when a box is set deep behind thick drywall, tile, or a mud ring and the standard short screw no longer reaches the device ears.

The TRM89M is steel with zinc plating, which is a mild corrosion coating meant for dry interior work. It holds up fine in conditioned space and in normal wall cavities. For wet locations, exterior boxes, coastal air, or anywhere washdown chemicals hit the hardware, go to a stainless 8-32 machine screw instead rather than relying on zinc.

A machine screw has a uniform straight thread and a blunt end, so it needs an existing tapped hole, a nut, or a threaded ear to bite into. The TRM89M is an 8-32 machine screw, which is exactly what a factory-tapped box ear or a device strap expects. A sheet metal or self-drilling screw cuts its own thread and is the wrong choice in those tapped holes, since it can strip them out.

The Metallics TRM89M 8-32 x 2 inch machine screw is made in the USA. That matters on public work, government facilities, and institutional projects where the submittal package has to show domestic origin on fasteners.

The TRM89M has a round head, which sits proud of the surface with a domed profile and seats on a flat hole rather than needing a countersink. If the drawing or the device calls for a flush finished surface, a countersunk flat head is the one to use. Round head is the standard for general device and box mounting where the head can stand above the plate.

One thread, one length, three drive types. Stocking the TRM89M gives a maintenance shop an 8-32 machine screw long enough at 2 inches to reach device ears on deep-set boxes, with a combination slotted, Phillips, and square recess so whatever bit is in the drill works. Pair it with the short 8-32 screws already in most boxes and you cover both the normal and the deep-box case without carrying separate Phillips and square variants.