Metallics TXV146 Screws 1/4-20 x 6 UNSLOTTED HWH #5 DR (25 pcs)

Unslotted hex washer head. There is no slot or recess in the top, so it is driven entirely from the hex with a socket or nut driver, not a screwdriver or bit. The washer face under the head spreads the clamp load on sheet metal or strap without a separate washer.

No. It is a #5 drill point screw, meaning it is self-drilling and cuts its own hole as it is driven. That is what the "#5 DR" in the designation refers to. Use a variable speed driver and steady pressure so the point cuts rather than work-hardens the metal.

A 6 inch length at 1/4-20 is meant for thick stack-ups, for example running through a mounting plate, spacer or blocking and into a steel member behind it. For thin sheet-to-sheet attachment, a 6 inch screw is far more than needed and the shank will protrude; pick a shorter length in the same 1/4-20 hex washer head drill point family. Measure your total grip plus the thickness of metal the point has to cut before choosing the length.

Yes. The 1/4-20 thread is a standard machine thread, so it will take a 1/4-20 nut where you want a through-bolted connection, and the hex washer head gives you a bearing face on that side. The #5 drill point also lets you drive it directly into steel when there is no back access.

25 pieces per pack. For a crew doing repeat hangers or standoff mounts, count the screws per assembly and multiply, since it is sold in the 25 count rather than loose.