CB38-532-TCT-CB-Counterbore-Trend-CB38-532TC-p-The-Trend-CB-counterbore-is-extensively-used-for-recessing-bolt-&-screw-heads-Supplied-with-a-HSS-slow-spiral-drill-bit-Fully-adjustable-a-hex-key-is-supplied-TCT-version-is-used-for-plywood-particle-boards-&-plastics-abrasive-Use-at-drilling-speeds-only-Not-suitable-for-ferrous-&-non-ferrous-metals-When-setting-up-ensure-flutes-of-drill-are-aligned-with-flute-of-counterbore-For-replacement-Twist-Drills-use-slow-spiral-type-e-