Metallics J142F Anchor 1/4 x 2 FH Hmmr Drv Ancr St-Zn (Jar 100)

Hammer drive anchors are nominal-diameter anchors: a 1/4 inch hammer drive anchor sets in a 1/4 inch hole drilled with a carbide masonry bit, drilled deeper than the 2 inch anchor length so drill dust can clear. The J142F is the 1/4 x 2 inch size, so you need at least 2 inches of usable hole depth in the concrete or block, plus the thickness of whatever you are fastening.

Drill the hole, hold the fixture in place, drop the anchor through it, then drive the pin flush with a hammer. Driving the pin expands the anchor body against the hole wall. No wrench, no torque setting, nothing to tighten afterward. That speed is the whole reason electricians use them for strut, clips, conduit straps and box mounting into concrete and block. The tradeoff: hammer drive anchors are permanent. Once set, they are not meant to be backed out and reused, so if you need a removable fastening use a machine screw anchor or a sleeve anchor instead.

No. Hammer drive anchors like the 1/4 x 2 J142F work by expanding against solid material, so they are for poured concrete, solid brick and the solid webs of masonry. Drive one into a hollow block cell or into drywall and the pin has nothing to expand against. For hollow block use a toggle or a sleeve type designed for hollow base material, and for drywall use a toggle bolt or self drilling drywall anchor.

Flat head. The FH in the Metallics J142F description means a flat countersunk head, which sits low and close to flush against the fixture rather than standing proud like a round or mushroom head. Pick flat head when the anchor is landing on a flat plate, strap or bracket and you do not want the head catching anything; pick a mushroom head version if you are pinning something with an oversized or slotted hole that needs more bearing area under the head.

The J142F is zinc plated steel, which is a dry indoor to lightly protected finish. It handles normal interior humidity fine, but in exterior exposure, wet locations, or anywhere near coastal salt air the plating will eventually corrode and the pin will seize or the head will rust off. For those spots go to a stainless hammer drive anchor or a stainless sleeve anchor.

The 2 inch figure on the J142F is the overall anchor length, not the grip. Part of that length has to sit inside the concrete to develop hold, so the thickness of the strap, clip or bracket you are pinning comes out of the 2 inches. For thicker fixtures or when you are going through a shim or a layer of insulation, step up to a longer hammer drive anchor so you keep enough embedment in the base material.

100 pieces per jar. That is the order unit for the Metallics J142F, part number J142F, so one jar covers a run of strut clips or conduit straps on a job without reordering. If you need several hundred, order in jar multiples.