Metallics JSHCZ142 Screw 1/4-20 x 2 SHCS St-Zn (Jar 100)

The Metallics JSHCZ142 is a 1/4-20 x 2 inch socket head cap screw. The 1/4-20 means a 1/4 inch nominal diameter with 20 threads per inch, which is the coarse (UNC) pitch for that diameter, and the 2 inch figure is the shank length under the head. It drives with a hex key, not a screwdriver, so you need a 3/16 inch Allen wrench for a standard 1/4-20 socket cap head.

These are steel with zinc plating (St-Zn), which is a coating for indoor and dry-to-damp use. Zinc plating gives light corrosion protection but it will eventually rust in direct weather, washdown, coastal air, or in contact with treated lumber. For exposed exterior runs or wet locations, use a stainless or hot-dip galvanized cap screw instead.

Each jar holds 100 of the 1/4-20 x 2 inch socket head cap screws. The jar pack is the sell unit, so it suits a service van or shop bin rather than a one-off repair.

Both thread the same, but the head and the driving method differ. A socket head cap screw like the JSHCZ142 has a cylindrical head driven from inside with a hex key, so it works where a wrench cannot swing around the head, in a counterbored hole, or where you want a lower profile. A hex head bolt needs clearance for a socket or open-end wrench on the outside of the head. If you are fastening inside an enclosure, a channel, or a tight bracket, the socket cap is the one that fits.

Order Metallics part number JSHCZ142. That number covers the 1/4-20 x 2 inch zinc plated steel socket head cap screw in the 100 count jar, and it is the only configuration under that number, so there is no length, finish, or pack option to specify.