US No. 1159 Busch Carbide Straight Fissure (Cylinder) Round Bur | Busch No. 21R 014 – HP | Pack of 6

Pack of 6. The Busch No. 21R 014 – HP (US No. 1159) is a round-end (domed) carbide cylinder cutter with a 1.4 mm (ISO 014) head on an HP shank for straight handpieces — the laboratory-oriented version of the 21R, distinct from the friction-grip 21R 014 FG. Made in Germany by Busch & Co. GmbH.

Why choose the HP version

In a straight handpiece, typically running up to roughly 40,000 rpm at the laboratory bench, the domed 1.4 mm cylinder gives both side- and end-cutting action for shaping acrylic, finishing crown and bridge frameworks and detailing plaster models without the sharp internal corners a flat-end cylinder leaves. Choose the FG version instead when the rounded No. 1159 profile is needed chairside in a high-speed turbine.

Also available: No. 21 012 – RA, No. 21 010 – FG, No. 21 010 – RA, No. 21 012 – FG, No. 21 016 – FG, No. 21 016 – HP, No. 21R 014 – FG.

Product Classification

This carbide cylinder round bur is classified under ISO standard 500 104 137 006 014 (US No. 1159), ensuring full compatibility and traceability within regulated professional environments. It is supplied as a convenient pack of 6, reducing downtime and ensuring a ready supply for high-volume workflows.

Instrument Dimensions

Per ISO 6360, the size number is the maximum head diameter in tenths of a millimeter. See our Busch Bur Size Chart for the full size conversion table, shank codes, and color ring guide.

Applications

The carbide cylinder round bur is well-suited for the following dental laboratory applications:

	Crown and Bridge Technology — Shaping, trimming and finishing of crown and bridge frameworks in the laboratory.
	Plastics Technology — Shaping, trimming and finishing of acrylic dentures and appliances.
	Model Making — Trimming and detailing of plaster and stone models.
	Model Casting Technique — Finishing and adjustment of cast metal frameworks.

Why Choose This Carbide Bur?

As a carbide cylinder round bur, this instrument combines a robust carbide cutting head with a cylindrical round geometry that facilitates both lateral and end-cutting action. The result is versatile, efficient material removal with minimal vibration and superior surface finish. Every bur in this product line is proudly made in Germany, reflecting decades of precision engineering expertise.

FAQ

What ISO classification does this bur carry? This bur is classified as ISO 500 104 137 006 014.

How many burs are included in each pack? Each pack contains 6 burs.

Is this a genuine Busch & Co. GmbH product? Yes, this carbide cylinder round bur is manufactured by Busch & Co. GmbH in Germany.

Compare With

Manufacturer literature: Busch catalogs and product brochures for this line are available in our Busch Burs Catalog Library.

Specifications: Busch No. 21R 014

With parallel sides and a domed end, the straight fissure round head cuts straight walls while leaving a rounded floor, which is kinder to the material than a sharp internal corner. A 1.4 mm head gives enough edge for shaping while still following tooth-sized contours.

Read the guides: Dental Laboratory Burs, Polishers & Abrasives · Bur Speed Chart · Dental Bur Glossary · All lab carbide cutters