Cobalt Letter Drill Bit Set A-Z - M35 HSS 26PCS Precision

In this review the 26PCS Cobalt Letter Drill Bit Set is assessed for tradespeople and hobbyists who drill through tough metals. The set stands out because it uses premium M35 high speed steel with 5% cobalt, which is the single biggest reason to consider it when cutting stainless steel, cast iron or other high tensile materials. The included indexed metal case and a full A to Z range make it a convenient kit for projects that need many small, labelled sizes rather than relying on single sizes.

Key Features

• High quality material: M35 HSS with 5% cobalt provides greater heat resistance and longer life when drilling hardened metals compared with ordinary HSS bits.
• Split point design: The 135 degree split point is self-centering to reduce walking and make hole starts more precise without needing a pilot mark.
• Fully ground twist: The ground flute geometry clears chips faster and lowers friction so the bits run cooler during extended cuts.
• Complete letter set: The A to Z wire letter assortment covers a wide range of small-hole needs for jewellery, electronics, model making and thin metal work.
• Indexed metal case: A stamped metal holder with size index keeps every bit organized and protected for jobsite transport.

Who It's For

This set is best for metalworkers, fabricators and serious DIYers who frequently drill stainless steel, cast iron, titanium alloys or other high tensile materials and need a broad selection of small, labelled sizes. The cobalt alloy and split point reduce the effort required to start holes in hardened stock, making it useful for repeated precision work.

It is less suited for users who only need a few common fractional sizes for wood or soft plastics, since a smaller fractional or metric set may be cheaper and easier to mount in standard chucks. Also, buyers seeking large diameter bits or industrial production tooling should look for job-specific coated or solid-carbide options.

Pros & Cons

Pros

• Wide A-Z selection provides many small sizes in one organized metal case.
• M35 cobalt construction gives improved heat resistance and cutting life on hard materials.
• 135 split point and fully ground flutes improve centering and chip evacuation for cleaner holes.
• Good value for projects requiring varied small sizes rather than single specialty bits.

Cons

• Some customers report mixed long-term durability and occasional premature dulling or breakage on heavy use, so results vary by application and technique.
• Wire letter sizes mean the set emphasizes small holes; it does not replace a full fractional or metric jobber set for larger diameters.

Specifications

Our Verdict

The 26PCS Cobalt Letter Drill Bit Set is a practical, value-focused kit for anyone drilling small holes in hardened metals and mixed materials. Its M35 cobalt construction and organized metal case make it a sensible choice for hobbyists and tradespeople needing many tiny sizes, though buyers expecting industrial longevity on heavy production runs may see variable durability.

Frequently Asked Questions

Are these drill bits suitable for stainless steel?
Yes, the M35 cobalt composition and split point are designed to cut stainless steel and other high tensile materials.

Does the set include an organizer?
Yes, all bits come in an indexed metal case that keeps letter sizes labelled and secure.

Will these fit a standard drill chuck?
Yes, the bits have round straight shanks intended for standard chucks and hand drills.