Metallics JW113SSD Washers 1/4 X 1 Fender SS (Jar 100)

The JW113SSD is a 1/4 inch fender washer with a 1 inch outside diameter, so it goes over 1/4-20 bolts, screws, and threaded rod. The large OD relative to the hole is the point of a fender washer: it spreads load across sheet metal, drywall, plywood, or a slotted strut so the head does not pull through.

They are stainless steel, which is what you want for exterior conduit supports, rooftop equipment, wet-location enclosures, and coastal jobs where a plain or zinc washer would bleed rust onto the finish. Pair them with stainless fasteners rather than plated steel so you are not mixing metals at the joint.

One hundred washers per jar, packed in a screw-top jar rather than a loose bag, which is why they hold up on a service van or a shop shelf without spilling. Order quantity is counted in jars of 100, so a single order unit covers a typical day of strut and sheet-metal work.

A 1 inch OD fender washer will bridge the slot in standard 1-5/8 inch strut and keep a 1/4 inch bolt head from pulling into the opening, and electricians use them that way routinely. What it will not do is key into the channel's inturned legs the way a purpose-made channel nut or square strut washer does, so for load-bearing hanger assemblies use the proper strut nut and keep the fender washer for sheet metal, box mounting, and drywall backing.

Same bolt size, very different footprint. A standard 1/4 inch SAE flat washer is roughly 5/8 inch across; the JW113SSD runs 1 inch, so it spreads the clamp load over a much larger area. Use the fender washer anywhere the material is thin or soft, or where you are covering an oversized or elongated hole. For a normal nut-and-bolt joint in steel, the standard flat washer is the right part.