Metallics JTMP101SS Screw 1/4-20 x 1 Truss PH MS 18-8 (Jar 100)

The material is 18-8 stainless, which is the common 300 series austenitic stainless used for corrosion resistance in damp, outdoor, and washdown locations. It is non-magnetic in the annealed state and won't rust like a plated carbon steel screw.

No. This is a machine screw with straight 1/4-20 machine threads, not a self-drilling or sheet metal screw. It needs a pre-tapped 1/4-20 hole, a nut, or a 1/4-20 threaded insert or channel nut. For fastening directly into unthreaded sheet metal, use a self-tapping sheet metal screw instead.

A truss head is wider and lower in profile than a pan head, so it spreads bearing load over a larger area and sits closer to flush. That matters on sheet metal, enclosure covers, and oversized or slotted holes where a pan head would pull through or stand too tall for a cover to close over it. If you need the head seated flush in the surface, you want a flat head in a countersunk hole instead, not a truss head.

100 screws per jar. The jar pack is the shop-counter format, so it works well for a van stock or a parts bin where you pull a handful at a time rather than buying by the box.

The 1 inch length is measured from under the truss head to the point, since truss heads are not countersunk. Subtract your material thickness and the nut height to see how much thread is left; on thin enclosure panels you'll have most of the inch available for a nut, washer, or channel nut.

Order Metallics part number JTMP101SS. That number covers the 1/4-20 x 1 inch truss head Phillips machine screw in 18-8 stainless, packed 100 to a jar.

Pairing 18-8 stainless with zinc or galvanized parts puts two dissimilar metals in contact, and in wet locations that drives galvanic corrosion of the zinc. For outdoor or damp installs, keep the nut, washer, and strut hardware stainless as well so everything matches. Inside a dry indoor enclosure the mix is far less of a concern.