SDS-max Carbide Rotary Hammer Bit 1-1/2 in x 21 in - Fast, Accurate

In this review the BOSCH HC5091 1-1/2 in x 21 in SDS-max Speed-X carbide rotary hammer bit is judged as a specialist bit for deep concrete work where durability and speed matter. The bottom line: it is best for professional tradespeople and serious DIYers who need a long, aggressive bit that cuts quickly and holds an accurate line through reinforced concrete. The review focuses on fit, cutting performance, longevity of the solid carbide head and practical suitability for SDS-max and compatible Hilti TE-Y/TE-FY hammers.

Key Features

• Universal fit: Fits all SDS-max hammers and Hilti hammers with TE-Y/TE-FY shanks so users can swap it into most heavy rotary hammers with no adapters required.
• Solid carbide head: The solid carbide head offers unrivaled hardness for drilling masonry and concrete, giving longer usable life before regrinding or replacement.
• Speed-X S-cutter design: Inclined side cutters provide an aggressive cutting edge to remove material faster, reducing time on long holes.
• Centric tip: The centric tip guides the bit through hard and reinforced concrete to improve accuracy and reduce wandering on deep holes.
• ANSI manufacture: Made to ANSI specification B212.14, ensuring consistent dimensions and performance across batches for predictable results on site.

Who It's For

The bit is aimed at professionals and experienced DIYers who drill deep holes in concrete, block or masonry and need a reliable, fast-cutting SDS-max solution that stays on line. Its 21 in length and aggressive cutters make it especially useful for anchor holes, through-holes for conduit runs and heavy-duty installations where speed matters.

Casual users who only drill occasional shallow holes, or those working with smaller rotary hammers or SDS-plus systems, should look for shorter or smaller-diameter bits to avoid unnecessary cost and to match their tool. Those seeking a bit guaranteed to survive extreme abuse should remember some users reported tip breakage under heavy misuse, so proper feed pressure and correct hammer settings are advised.

Pros & Cons

Pros

• Fast cutting thanks to the inclined side cutters and S-cutter geometry, reducing hole time on long runs.
• Accurate hole placement from the centric tip that resists walking in reinforced concrete.
• Strong compatibility with SDS-max and Hilti TE-Y/TE-FY drive hammers for flexible tool use.
• Durable solid carbide head stays sharp longer than many competitor bits under normal use.

Cons

• Some users report mixed durability under extreme conditions, with a few instances of tip breakage after heavy use.
• Long 21 in length may be unnecessary for light or occasional drilling and can be harder to control for novice users.

Specifications

Brand	Bosch
Model	HC5091
Shank type	SDS-max (fits TE-Y/TE-FY)
Diameter	1-1/2 in
Length	21 in
Tip material	Solid carbide head
Standard	Manufactured to ANSI B212.14

Our Verdict

The BOSCH HC5091 1-1/2 in x 21 in SDS-max bit is a sensible purchase for professionals who need a long, fast, and accurate carbide bit for concrete and masonry. It offers strong cutting speed and centric accuracy at a reasonable value, though users should respect proper drilling technique to avoid the isolated tip failures reported by some customers.

Frequently Asked Questions

Will this fit my rotary hammer?
It fits SDS-max hammers and Hilti hammers with TE-Y/TE-FY shanks, so check your tool uses SDS-max or one of the compatible Hilti shank types.

Is the bit suitable for reinforced concrete?
Yes, the centric tip and carbide head are designed to guide through hard and reinforced concrete, improving accuracy compared with standard bits.

How long will the tip stay sharp?
The solid carbide head stays sharper longer than many competitors under normal use, but longevity depends on material, feed pressure and operator technique.