US No. 557 Bur – Busch Crosscut Straight Fissure Carbide, Made in Germany

The US No. 557 is the standard crosscut straight fissure bur of American operative dentistry: a flat-end cylinder with cross-cut blades and a 1.0 mm head. Busch & Co. manufactures it in Germany as Busch No. 31 010 in tungsten carbide and 36 010 in steel, plus the long-head 557L and the surgical 557X. Every 557 on this page is made by Busch in Engelskirchen and ships from our US warehouse.

Which US 557 Do You Need?

FG = friction grip, 1.6 mm shank for the high-speed handpiece. HP = 2.35 mm shank for the straight handpiece. FG-XL = 25 mm surgical-length friction grip. See the Busch Bur Size Chart for shank and head dimensions.

Clinical Uses of the 557 Bur

• Cavity preparation: opening through enamel, establishing straight walls and the flat floor of Class I and Class II preparations, and cutting proximal boxes.
• Restoration removal: the cross-cut blades break up old amalgam and composite quickly and clear the debris instead of packing with it.
• Sectioning: dividing multi-rooted teeth for surgical extraction, where the 557X puts the same cutting head on a 25 mm shank for reach and visibility.
• Laboratory and denture work: the HP carbide and steel versions trim acrylic, adjust denture bases and reduce plaster and stone models in the straight handpiece.

A crosscut fissure bur cuts fast and leaves a rougher wall. When you need a smooth cavity wall or a finish line, follow the 557 with its plain-cut twin, the US No. 57 (Busch 21 010), or a finishing bur.

Speed and Technique

Run the FG 557 in the high-speed handpiece with continuous water spray and light, intermittent pressure; let the cross-cut blades do the work rather than leaning on the bur. Use the HP versions in the straight handpiece at laboratory speeds. Maximum recommended speeds for every Busch shape are listed in our Dental Bur Speed Chart, and reprocessing steps for carbide and steel burs in the Bur Sterilization Guide.

Made in Germany by Busch & Co.

Busch & Co. has manufactured rotary instruments in Engelskirchen, Germany since 1905. Every 557 here is a genuine Busch instrument: precision-ground tungsten carbide or steel heads on concentric shanks, produced 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 557 bur? Busch No. 31 010 for the carbide 557 in FG or HP, and 36 010 for the steel 557. The long-head 557L is Busch 31L 010; the surgical 557X is Busch 31RL 010 on a 25 mm FG-XL shank.

What size is a 557 bur? The 557 has a 1.0 mm head diameter (ISO size 010) on a flat-end cylinder with cross-cut blades. The FG carbide carries the full ISO code 500 314 107 007 010.

What is the difference between a 557 and a 57? Same shape and size. The 557 is crosscut for fast, aggressive cutting and debris clearance; the 57 (Busch 21 010) is plain-cut and leaves a smoother wall. Many clinicians open with the 557 and refine with the 57.

557 vs 557L vs 557X? The 557L has a longer cutting head for deeper preparations. The 557X is the surgical version: a 25 mm FG-XL shank for reach when sectioning teeth and roots, with a rounded end.

Can I cut a crown off with a 557? It will cut through metal, but it dulls quickly on it. For crown removal, the Busch Crown Cutter burs are built for the job and last far longer.

Are Busch 557 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 · All Straight Fissure (Cylinder) Burs