Metallics JDS157 Screws 8 X 1-1/2 Ih Hx 1/4Hd Sl TS St (Jar 100)

The JDS157 is made to self-start in thin metal from 0.015 to 0.050 inch thick, and it will also bite into resin-filled plywood. The gimlet point does the starting, so no pilot hole is needed in that gauge range. Go thicker than 0.050 inch and you want a different point style, because a Type A thread is not cut for heavy stock.

Either. The head is an indented hex with a slot, so a 1/4 inch nut driver works and a flat blade fits the slot when you cannot get a driver square on the head. Head width runs 0.244 to 0.250 inch, width across corners is 0.272 inch, slot width 0.045 to 0.054 inch and slot depth 0.052 to 0.066 inch.

A Type A screw like the JDS157 has wider spaced threads than a Type AB and a gimlet point, which makes it faster to start and faster to drive in thin sheet. Type AB uses a finer, machine-screw-pitch thread and is the better choice when you need more threads engaged in slightly heavier material or want a more uniform pull-out in plastic and castings. For 0.015 to 0.050 inch sheet, the Type A is the one that bites with the fewest turns.

They are steel with a zinc finish, which is a dry-interior or lightly protected coating. Zinc plating handles indoor light metal assembly and framing fine, but it is not a marine or sustained-exposure plating, so for exterior or wet locations step up to a stainless or hot-dip equivalent.

Minimum torsional strength on the JDS157 is 39 lb-in, with a case hardness of Rockwell C28-38 and AISI 1016-1024 steel. On an impact driver in thin sheet that is plenty, but it also means a gun set wide open will twist heads off once the screw bottoms out. Clutch it or finish by hand.

Dimensions follow ASME B18.6.3-2010 and the thread form follows ASME B18.6.4, with material to AISI 1016-1024. Thread count is 15 per inch. Note that #9 diameter dimensions in this family fall outside ASME B18.6.4, but the #8 does not. These are not Buy American compliant and are not ARRA compliant, with multiple countries of origin, so on a federally funded job they will not pass a domestic-sourcing spec.

They ship 100 to a jar, and the jar is the minimum order unit. Jar weight is listed at 0.75 lbs. Metallics does build other sizes and quantities of this screw by request if a job needs a different length or diameter.

The head sits on an integral washer face measuring 0.322 to 0.348 inch outside diameter and 0.019 to 0.031 inch thick. Head height runs 0.096 to 0.110 inch. That washer spreads the load on thin sheet so the head is less likely to pull through 0.015 inch stock.