Why are some drill bits black and some silver?

If you’re drilling through hardened metal, even an HSS bit can wear out quickly, and you may need one made from tungsten carbide or titanium. The black or blue-gray color on metal boring bits comes from a coating or black oxide or titanium carbo-nitride, designed to reduce friction and extend bit life.

What is a #58 drill bit?

A number 58 bit has a diameter of 0.042 inches.

What do different colour drill bits mean?

Masonry drill bits normally silver have a wide head on. Gold bits are normally pointed and are for drilling wood etc. Black bits are also pointed headed but for drilling metals.

What is the best set of drill bits to buy?

Hollow Punch Set, 6 Pc. Metric Drill/Tap/Deburr Bit Set, 13 Pc. Titanium High Speed Steel Step Bit, 1 Pc. Titanium High Speed Steel Stepless Drill Bit Set, 3 Pc. Drill Stop Set, 7 Pc.

Can you use cobalt steel drill bits for hand held drilling?

Only for use in drill presses. Cobalt steel bits are heat resistant and maintain their sharp edges when drilling hard material. They are for use in both hand-held drilling and machine-tool applications. Harder, stronger, and more wear resistant than cobalt steel, solid-carbide bits maintain their sharp edges longer.

How do you use a flexible shaft drill bit?

Keep flexible-shaft drill bits centered between studs and drywall. The shaft is made of spring steel instead of hardened steel, so it flexes while drilling, allowing you to drill inside walls or between floors. Use these guides to position flexible-shaft drill bits.

What is a 1/4 drill bit used for?

Use these bits on brittle material such as block and brick. The 1/4″ hex shank allows these bits to be used with standard impact drivers. These hollow bits cut with their outside edge for drilling holes larger than 1 1/2″ in diameter. Use these diamond-coated hollow bits for wet drilling of masonry, concrete, and rebar with a drilling rig.