US No. 1157 Bur – Busch Straight Fissure Carbide, Made in Germany

The US No. 1157 is the American number for a straight fissure bur with a 1 mm head (ISO size 010): a parallel-sided cylinder with a rounded end, so it cuts straight walls with rounded internal line angles. Busch & Co. manufactures it in Germany as Busch No. 21R 010. Every US No. 1157 on this page is a genuine Busch instrument and ships from our US warehouse.

Which US No. 1157 Do You Need?

US No.	Busch No.	Material	Cut	Shank	Best for	Pack
1157	21R 010	Carbide	Plain-cut	FG	High-speed handpiece, rounded end	6
1157	21R 010	Carbide	Plain-cut	HP	Straight handpiece: laboratory and denture work, rounded end	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. 1157

Cavity preparation: opening through enamel and establishing the straight walls and flat floor of Class I and Class II preparations, including proximal boxes.
Restoration removal: cutting out old amalgam and composite; crosscut versions clear the debris instead of packing with it.
Sectioning: dividing crowns and multi-rooted teeth, where the surgical-length versions add reach and visibility.
Laboratory and denture work: the HP carbide and steel versions trim acrylic, adjust denture bases and reduce plaster models in the straight handpiece.

At 1 mm the No. 1157 is the standard operative size.

The No. 1157 is plain-cut; its crosscut twin in the same shape and size is the US No. 1557 (Busch 31R 010). Crosscut blades cut faster and clear debris; plain-cut blades leave a smoother wall.

Speed and Technique

Run the FG versions in the high-speed handpiece with continuous water spray and light, intermittent pressure; let the blades do the work. HP versions run at laboratory speed in the straight handpiece. 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 1157 bur? Busch No. 21R 010 in carbide (FG/HP).

What size is a No. 1157 bur? The No. 1157 has a 1 mm head diameter (ISO size 010) on a straight fissure bur head, ISO shape 137 (cylinder, round end).

What is the difference between a No. 1157 and a No. 1557? Same shape and size; one is plain-cut and the other crosscut. The No. 1157 is plain-cut — crosscut cuts faster and clears debris, plain-cut leaves a smoother surface.

Are Busch No. 1157 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. 1158, US No. 1159