US No. 63 Bur – Busch Straight Fissure Carbide, Made in Germany

The US No. 63 is the American number for a straight fissure bur with a 2.3 mm head (ISO size 023): a parallel-sided cylinder with a flat end, so it cuts straight walls and a flat floor in one motion. Busch & Co. manufactures it in Germany as Busch No. 21 023. Every US No. 63 on this page is a genuine Busch instrument and ships from our US warehouse.

Which US No. 63 Do You Need?

HP (2.35 mm shank, straight handpiece). See the Busch Bur Size Chart for head and shank dimensions.

Clinical Uses of the US No. 63

• 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 2.3 mm the No. 63 is a wide head for bulk reduction, sectioning and laboratory cutting.

The No. 63 is plain-cut; its crosscut twin in the same shape and size is the US No. 563 (Busch 36 023). 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.

FAQ

What is the Busch number for a US 63 bur? Busch No. 21 023 in carbide (HP).

What size is a No. 63 bur? The No. 63 has a 2.3 mm head diameter (ISO size 023) on a straight fissure bur head, ISO shape 107 (cylinder, flat end).

What is the difference between a No. 63 and a No. 563? Same shape and size; one is plain-cut and the other crosscut. The No. 63 is plain-cut — crosscut cuts faster and clears debris, plain-cut leaves a smoother surface.

Are Busch No. 63 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. 61, US No. 62