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Clear plastic case holding 21 cobalt drill bits in graduated sizes

Century Drill & Tool

Century Drill & Tool ratchet

SKU CH-0YEB-QT6A3

A 21-piece cobalt drill bit set in M35 steel with 5% cobalt cuts hardened metals including stainless steel, uses 135° self-centering points that start without a center punch.

  • ColorTransparent
  • M35 steel with 5% cobalt cuts hard metals including stainless steel
  • 135° quick-cut points self-centre and penetrate faster with less pressure
  • Bits will not walk or wander at the starting surface
  • Extremely heat resistant for use at 1500 RPM or more
  • 21 piece set covers 1/16" to 3/8" by 64ths

Century 21-piece cobalt drill set

This 21-piece set from Century Drill & Tool uses M35 steel with 5% cobalt to cut extremely hard metals including stainless steel. The 135° quick-cut points are self-centering and penetrate faster with less pressure, preventing the bit from walking at the start. Designed for high heat resistance, the bits require power units running at 1500 RPM or more for maximum efficiency. Sizes range from 1/16" to 3/8" by 64ths.

Suited for metalworkers drilling stainless

Workers who need self-centering points and cobalt heat resistance for tough alloys will benefit from this set. It is not for users limited to drills below 1500 RPM, as the bits require higher speed for peak performance. Buyers who need sizes larger than 3/8" or smaller than 1/16" must look elsewhere. The transparent case color may not suit those wanting a metal index.

Covers 1/16" to 3/8" in 64th increments

The 21 bits handle common fractional sizes from 1/16" through 3/8" for general metal drilling tasks. Cobalt construction provides headroom for sustained cutting in stainless steel without rapid dulling. The set runs out above 3/8" diameter, so larger holes require separate bits. RPM below 1500 reduces cutting efficiency and bit life in hard materials.

Highlights

  • M35 steel with 5% cobalt cuts hard metals including stainless steel
  • 135° quick-cut points self-centre and penetrate faster with less pressure
  • Bits will not walk or wander at the starting surface
  • Extremely heat resistant for use at 1500 RPM or more
  • 21 piece set covers 1/16" to 3/8" by 64ths

Specifications

BrandCENTURY DRILL & TOOL
ColorTransparent

Questions about this item

What power-tool speed do I need to run these 135° cobalt bits at their rated 1,500 RPM minimum?

Use any drill or driver that can reach at least 1,500 RPM; slower speeds will not give the heat-resistant M35 steel its full cutting efficiency.

Will the 1/16" to 3/8" 64th-increment sizes cover the same holes as my older fractional-inch bits?

Yes, the 21-piece range matches standard fractional sizes, so existing pilot holes and clearance holes line up without new layout work.

How can I confirm the self-centering points are working right after the first hole?

The bit should start on contact without a center punch and produce a clean, round entry with no wandering or walking on the workpiece surface.

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