US No. 59 Bur – Busch Straight Fissure Carbide, Made in Germany

The US No. 59 is the American number for a straight fissure bur with a 1.4 mm head (ISO size 014): 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. 21 014 and Busch No. 21L 014. Every US No. 59 on this page is a genuine Busch instrument and ships from our US warehouse.

Which US No. 59 Do You Need?

US No.	Busch No.	Material	Cut	Shank	Best for	Pack
59	21 014	Carbide	Plain-cut	FG	High-speed handpiece	6
59	21 014	Carbide	Plain-cut	RA	Slow-speed contra-angle	6
59	21 014	Carbide	Plain-cut	HP	Straight handpiece: laboratory and denture work	6
59L	21L 014	Carbide	Plain-cut	HP	Longer head for deeper preparations	6

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

Clinical Uses of the US No. 59

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 1.4 mm the No. 59 is a wide head for bulk reduction, sectioning and laboratory cutting.

The 59L (Busch 21L 014) carries a longer cutting head for deeper boxes and taller walls.

The No. 59 is plain-cut; its crosscut twin in the same shape and size is the US No. 559 (Busch 36 014). 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 59 bur? Busch No. 21 014 in carbide (FG/RA/HP). The 59L is Busch 21L 014.

What size is a No. 59 bur? The No. 59 has a 1.4 mm head diameter (ISO size 014) on a straight fissure bur head, ISO shape 107 (cylinder, flat end).

What is the difference between a No. 59 and a No. 559? Same shape and size; one is plain-cut and the other crosscut. The No. 59 is plain-cut — crosscut cuts faster and clears debris, plain-cut leaves a smoother surface.

What do the letters after No. 59 mean? The 59L (Busch 21L 014) carries a longer cutting head for deeper boxes and taller walls.

Are Busch No. 59 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. 57, US No. 58, US No. 60, US No. 61