Metallics JFW20 5 x 5/8 in. Flat Head Slotted Wood Screws - Steel Zinc - Each

The JFW20 is a #5 x 5/8 inch flat head slotted wood screw in zinc-plated steel, with 20 threads per inch. It ships in a jar and the order minimum is 100 count, so you are buying it by the jar of 100 rather than by the single screw.

It will, if the hole is countersunk. The flat head measures 0.22 to 0.252 inch across with a head height of 0.075 inch, so the head needs a countersunk seat that diameter to pull down level with the surface. In sheet metal straps or boxes with a pre-countersunk hole it seats flush; on a flat, un-countersunk surface the head will stand slightly proud.

Metallics lists the JFW20 as ARRA compliant and Buy American compliant. Country of origin is China. If your specification allows ARRA/Buy American compliance determinations on fasteners, this flags as compliant; if the job demands domestic melt and manufacture, verify against your contract language.

The drive is slotted, with a slot width of 0.035 to 0.043 inch and a slot depth of 0.022 to 0.034 inch. That is a shallow, narrow slot on a #5 screw, so a thin flat-blade cabinet tip is what seats in it. Slotted drives cam out easily under power, so most installers run these by hand or on a very low-torque clutch setting.

The JFW20 has a tapered point, which is the traditional wood screw geometry: it is not a self-drilling or self-tapping point. It starts in soft wood with an awl mark, but in hardwood, trim, or anywhere near an edge you want a pilot hole to avoid splitting. At 5/8 inch long it is meant for thin stock or fastening a plate or strap down to a wood surface, not for structural pull.

On short wood screws like this one the thread runs nearly to the head. Metallics states that screws of nominal lengths too short to accommodate the minimum thread length have threads extending as close to the underside of the head as practicable; the 2/3 thread rule only kicks in at lengths of 1 inch and up. At 5/8 inch you get essentially full thread engagement over the whole shank.

Dimensions and threads follow ASME B18.6.1, with the thread standard cited as ASME B18.6.1-1997. That is the inch-series wood screw standard, so head profile, slot, and thread pitch match any other B18.6.1 #5 flat head slotted screw. Useful if a submittal or spec calls out the standard rather than a part number.

The JFW20 is zinc-plated steel, which is an indoor/dry-location finish. It handles general interior electrical and millwork use, but it is not a marine or sustained-wet-location fastener. For outdoor boxes, damp crawlspaces, or treated lumber, step up to stainless or hot-dip galvanized instead of zinc-plated steel.

Yes. The JFW series covers other diameters and lengths, and Metallics notes other sizes and quantities are available by request. JFW20 specifically is the #5 x 5/8 inch flat head slotted version; if you need longer reach into a wood substrate, specify the length you want rather than stacking washers under this one.