Metallics BFR21 Masonry Drill Bit Carbide Slow Spiral Dia 1/2" 4 Shank 1/4" (1pc)

The BFR21 has a 1/4 inch shank, so it drops into any 1/4 inch or larger chuck on a standard rotary or hammer drill. It is a round shank bit, not SDS, so it will not seat in an SDS-plus or SDS-max rotary hammer. If your tool is SDS only, you need an SDS-shank masonry bit instead.

It cuts a 1/2 inch diameter hole. Match that to the anchor you are setting: 1/2 inch sleeve anchors, wedge anchors and drop-in anchors are all sized by the hole they need, and a 1/2 inch anchor body generally calls for a 1/2 inch bit. Drilling with the wrong diameter is the usual reason an anchor spins or will not seat.

This is a carbide tipped masonry bit, meant for concrete, block, brick and mortar. The carbide tip crushes masonry rather than cutting a chip the way a twist bit does, so it is the wrong tool for steel and it will tear rather than cut clean in wood. Keep a separate twist or spade bit for those materials.

Slow spiral refers to the flute pitch. The BFR21 uses a slow spiral flute, which clears dust at a steadier rate and holds up better under the percussion of hammer drilling in hard concrete. Fast spiral bits evacuate dust quicker and suit softer block and brick where you want speed. For hard aggregate concrete, the slow spiral is the one to reach for.

One bit per order, supplied in a pouch. If you are drilling a run of anchor holes in hard concrete, order spares, since carbide tips dull or chip and a worn bit is what burns up drilling time on a job.

Order Metallics BFR21. That is the manufacturer part number for the 1/2 inch diameter, 1/4 inch shank slow spiral carbide masonry bit, and it is the number to quote on a purchase order or a restock for an electrical or MRO crib.