US No. 58 Busch Carbide Straight Fissure (Cylinder) Bur | Busch No. 21 012 – FG | Pack of 6

Pack of 6. Busch No. 21 012 – FG (US No. 58) is the 1.2 mm (ISO 012) friction-grip member of the 21 carbide straight fissure (cylinder) family — a step up in diameter from the No. 57 and below the No. 60. Its FG shank is intended for high-speed turbine handpieces; Busch & Co. GmbH manufactures it in Germany, and a latch RA version of the same head is listed separately.

Why choose the FG version

The 1.2 mm flat-end cylinder is typically the everyday high-speed fissure bur for Class I and Class II preparations — wide enough for efficient outline form and flat pulpal floors, yet still conservative. In a turbine or electric high-speed handpiece it cuts enamel cleanly under water spray; choose the RA-shank 21 012 for low-speed contra-angle work, or the 21 010 / 21 016 FG for narrower or wider preparations.

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

Product Specifications

• Type: Carbide, Cylinder Flat, Excavating and Fissure Bur
• US Number: 58
• Catalog Reference: 21 012
• ISO Classification: 500 314 107 006 012
• Shank: FG (Friction Grip)
• Pack Quantity: 6 burs per pack

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

This carbide cylinder fissure dental bur is particularly suited for cavity and fissure preparation, where precise, controlled cutting geometry is essential. The flat-end cylinder form allows the clinician to establish clean, defined cavity walls and floors with minimal risk of over-extension.

The carbide cylinder fissure dental bur is well-suited for the following clinical procedures:

Cavity/Fissure Preparation — Opening, extending and shaping cavities and fissures with controlled removal of enamel and dentin.

German Engineering Quality

Every carbide cylinder fissure dental bur in this range is produced in Germany, reflecting Busch & Co. GmbH's longstanding commitment to precision manufacturing. The result is an instrument that maintains its cutting edge through extended clinical use, reducing the need for frequent replacement and supporting consistent procedural outcomes.

FAQ

What shank type does this bur use? This bur features an FG (Friction Grip) shank, compatible with standard high-speed handpieces.

How many burs are included per pack? Each pack contains 6 individual carbide cylinder fissure dental burs.

What is the ISO classification for this bur? The ISO classification is 500 314 107 006 012.

Compare With

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