US No. 171 Bur – Busch Tapered Fissure Carbide, Made in Germany

The US No. 171 is the American number for a tapered fissure bur with a 1.2 mm head (ISO size 012): a cone that narrows toward the tip, so the walls it cuts diverge toward the occlusal: the geometry crown and inlay preparations depend on. Busch & Co. manufactures it in Germany as Busch No. 23 012 and Busch No. 23L 012. Every US No. 171 on this page is a genuine Busch instrument and ships from our US warehouse.

Which US No. 171 Do You Need?

US No.	Busch No.	Material	Cut	Shank	Best for	Pack
171	23 012	Carbide	Plain-cut	FG	High-speed handpiece	6
171	23 012	Carbide	Plain-cut	HP	Straight handpiece: laboratory and denture work	6
171L	23L 012	Carbide	Plain-cut	FG	Longer head for deeper preparations	6
171L	23L 012	Carbide	Plain-cut	HP	Longer head for deeper preparations	6

FG (friction grip, 1.6 mm shank, high-speed handpiece). HP (2.35 mm shank, straight handpiece). See the Busch Bur Size Chart for head and shank dimensions.

Clinical Uses of the US No. 171

Crown preparation: axial reduction with built-in taper for full-coverage crowns and bridge abutments.
Inlay and onlay preparation: cavity walls that diverge toward the occlusal for a path of insertion.
Cavity preparation: extending and shaping preparations where a flat floor and tapered walls are wanted.
Sectioning and laboratory work: the surgical-length versions section teeth and roots; the HP carbide and steel versions cut acrylic and plaster in the straight handpiece.

At 1.2 mm the No. 171 is the standard operative size for crown and inlay walls.

The 171L (Busch 23L 012) carries a longer cutting head for deeper boxes and taller walls.

The No. 171 is plain-cut; its crosscut twin in the same shape and size is the US No. 701 (Busch 38 012). Crosscut blades cut faster and clear debris; plain-cut blades leave a smoother wall.

Speed and Technique

Keep the bur parallel to the intended path of insertion so the taper of the head becomes the taper of the wall; use water spray with the FG versions and laboratory speed for HP. Maximum recommended speeds for every Busch shape are in our Dental Bur Speed Chart, and reprocessing steps in the Bur Sterilization Guide.

Made in Germany by Busch & Co.

Busch & Co. has manufactured rotary instruments in Engelskirchen, Germany since 1905. Every instrument on this page is a genuine Busch product, precision-ground on a concentric shank under ISO-certified quality management and guaranteed to arrive free of manufacturing defects under our Busch arrival guarantee.

Dental Instruments, Tools, Burs, Diamonds and Polishers Made In Germany

FAQ

What is the Busch number for a US 171 bur? Busch No. 23 012 in carbide (FG/HP). The 171L is Busch 23L 012.

What size is a No. 171 bur? The No. 171 has a 1.2 mm head diameter (ISO size 012) on a tapered fissure bur head, ISO shape 168 (cone, flat end).

What is the difference between a No. 171 and a No. 701? Same shape and size; one is plain-cut and the other crosscut. The No. 171 is plain-cut — crosscut cuts faster and clears debris, plain-cut leaves a smoother surface.

What do the letters after No. 171 mean? The 171L (Busch 23L 012) carries a longer cutting head for deeper boxes and taller walls.

Are Busch No. 171 burs reusable? Yes. Carbide and steel burs are cleaned, disinfected and sterilized between patients and replaced when they dull; the Bur Sterilization Guide gives the validated steps.

Related resources: US Bur Number Finder · Bur Comparison Chart · Speed Chart · Bur Glossary · Nearby sizes: US No. 169, US No. 170, US No. 172