Metallics JDS154V Screws 8 x 1 Hx 1/4 Ihw Sl SMA Zn (Jar 500)

The Metallics JDS154V is made to self-start in thin metal from 0.015 to 0.050 inches thick, and it also works in resin-filled plywood. Its gimlet point and the wide 15 threads per inch spacing are what let it form its own thread in sheet stock. Thicker steel needs a different fastener, since a Type A thread will not cut heavy gauge.

Either one. The head is an indented hex with a slot, so it takes a 1/4 inch hex bit or socket (head width measures 0.244 to 0.250 inches, 0.272 across the corners) or a flat blade in the slot, which runs 0.045 to 0.054 inches wide and 0.052 to 0.066 inches deep. Most electricians run them with a 1/4 inch magnetic bit and keep the slot as the backup for tight spots.

It's an integral hex washer head, not a separate washer. The washer flange runs 0.322 to 0.348 inches outside diameter and 0.019 to 0.031 inches thick, with overall head height of 0.096 to 0.110 inches. That flange spreads the load on thin sheet and keeps the head from pulling through, which is why these get used on sheet metal boxes and duct.

Thread spacing and point. The Type A in the JDS154V has wider spaced threads than a Type AB and a gimlet point, which makes it faster to start and better suited to thin sheet (0.015 to 0.050 inches) and resin-filled plywood. A Type AB uses finer, more closely spaced threads and generally holds better in slightly heavier material or where you want more threads engaged in a given depth.

Torsional strength on the JDS154V is rated 39 lb-in minimum, with case hardness of Rockwell C28-38 on AISI 1016-1024 steel. That's enough for hand drivers and standard drill/drivers at moderate clutch settings. An impact driver can exceed 39 lb-in easily on a #8, so back the torque off rather than burying the head.

These are zinc plated steel. Zinc plating handles indoor and dry or occasionally damp conditions, but it is not a stainless or hot-dip finish, so continuous exposure to weather, chlorides, or wash-down areas will eventually corrode the plating. For exterior or coastal work, specify a stainless or hot-dip galvanized tapping screw instead.

Metallics lists the JDS154V as both ARRA compliant and Buy American compliant. Country of origin is recorded as multiple, so if your contract requires documented origin per shipment, ask for the cert with the order.

Dimensions follow ASME B18.6.3-2010 and the thread form follows ASME B18.6.4, with material to AISI 1016-1024. One caveat worth knowing if you are specifying across the JDS line: dimensions for #9 diameter screws are independent of ASME B18.6.4. The JDS154V itself is a #8 x 1 inch.

The JDS154V ships as a jar of 500 screws, and 500 count is the order minimum, so one jar is the smallest buy. Jar weight is listed at 2.65 lbs. Handy for stocking a van or a shop bin rather than counting out loose fasteners on site.