New Truss Head Phillips Drive Upholstery and Chair Bottom Screws with Black Chrome Finish.  Each bid quantity is for a Lot of One Hundred (100) Screws.  You may bid / buy any number of lots, up to the total quantity available above.

These were purchased at an industrial sale earlier this year, and they were brand new in unmarked bulk boxes.  The company used them to secure upholstery around the pads on high end fitness equipment.  They should be miles ahead of upholstery tacks, which tend to loosen and pull away.  Additionally, the threads have small notches to help reduce splitting when used in wood.  The heads are absolutely smooth on the underside to prevent twisting the fabric as the screw turns and tightens.  The truss head design exerts pressure on the outer rim of the head, thereby providing a larger bearing surface against the fabric.  The finish is some kind of brownish black chrome, which is supposed to resist corrosion better than screws that are simply painted.

These should work equally well for sheet metal and thin laminates.

According to the calipers

Overall length:  .608

Length from tip to underside of head:  .545"

Head diameter:  .397"

Threads:  .175" diameter, approx #8

Finish:  Black/Brown Chrome Plated Steel