US No. 170 Bur – Busch Tapered Fissure Carbide, Made in Germany

The US No. 170 is the American number for a tapered fissure bur with a 1 mm head (ISO size 010): 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. 23 010 and Busch No. 23L 010. Every US No. 170 on this page is a genuine Busch instrument and ships from our US warehouse.

Which US No. 170 Do You Need?

US No.	Busch No.	Material	Cut	Shank	Best for	Pack
170	23 010	Carbide	Plain-cut	FG	High-speed handpiece	6
170	23 010	Carbide	Plain-cut	HP	Straight handpiece: laboratory and denture work	6
170L	23L 010	Carbide	Plain-cut	FG	Longer head for deeper preparations	6
170L	23L 010	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. 170

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 mm the No. 170 is the standard operative size for crown and inlay walls.

The 170L (Busch 23L 010) carries a longer cutting head for deeper boxes and taller walls.

The No. 170 is plain-cut; its crosscut twin in the same shape and size is the US No. 700 (Busch 38 010). 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 170 bur? Busch No. 23 010 in carbide (FG/HP). The 170L is Busch 23L 010.

What size is a No. 170 bur? The No. 170 has a 1 mm head diameter (ISO size 010) on a tapered fissure bur head, ISO shape 168 (cone, flat end).

What is the difference between a No. 170 and a No. 700? Same shape and size; one is plain-cut and the other crosscut. The No. 170 is plain-cut — crosscut cuts faster and clears debris, plain-cut leaves a smoother surface.

What do the letters after No. 170 mean? The 170L (Busch 23L 010) carries a longer cutting head for deeper boxes and taller walls.

Are Busch No. 170 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. 168, US No. 169, US No. 171, US No. 172