US No. 7 Bur – Busch Round Carbide & Steel, Made in Germany
The US No. 7 is the American number for a round bur with a 2.1 mm head (ISO size 021): a spherical head that cuts on every surface, so it excavates, opens and shapes in any direction. Busch & Co. manufactures it in Germany as Busch No. 1 021 and Busch No. 1S 021 (plus 2 further variants below). Every US No. 7 on this page is a genuine Busch instrument and ships from our US warehouse.
Busch & Co. GmbH
US No. 7 Busch Carbide Round Bur | Busch No. 1 021 – FG | Pack of 6
Regular price $35.99Unit price-
Busch & Co. GmbH
US No. 7 Busch Carbide Round Bur | Busch No. 1 021 – HP | Pack of 6
Regular price $35.99Unit price -
Busch & Co. GmbH
US No. 7 Busch Carbide Round Bur | Busch No. 1 021 – RA | Pack of 6
Regular price $35.99Unit price -
Busch & Co. GmbH
US No. 7 Busch Steel Round Bur | Busch No. 1 021 – HP | Pack of 6
Regular price $17.99Unit price -
Busch & Co. GmbH
US No. 7S Busch Carbide Round Bur | Busch No. 1S 021 – FG | Pack of 6
Regular price $37.99Unit price -
Busch & Co. GmbH
US No. 7S Busch Carbide Round Bur | Busch No. 1S 021 – RA | Pack of 6
Regular price $38.99Unit price -
Busch & Co. GmbH
US No. 7SX Busch Carbide Round Bur | Busch No. 1SX 021 – SX-Cut – RA | Pack of 6
Regular price $41.99Unit price -
Busch & Co. GmbH
US No. 7SXM Busch Carbide Round Bur | Busch No. 1SXM 021 – SXM-Cut – HP | Pack of 2
Regular price $22.99Unit price -
Busch & Co. GmbH
US No. 7SXM Busch Carbide Round Bur | Busch No. 1SXM 021 – SXM-Cut – RA | Pack of 6
Regular price $47.99Unit price -
Busch & Co. GmbH
US No. 7SXM Busch Carbide Round Bur | Busch No. 1SXM 021 – SXM-Cut – RA-L | Pack of 2
Regular price $24.99Unit price
Reference pages already linked from this collection, in one place.
Which US No. 7 Do You Need?
Choose by shank first, then by cut; every active product in the collection is linked once below by its Busch number.
FG (high-speed handpiece)2 items
RA and RA-L (slow-speed contra-angle and surgical length)5 items
| Busch No. | US No. | Material | Cut | Shank | Best for | Pack |
|---|---|---|---|---|---|---|
| 1 021 | 7 | Carbide | Plain-cut | RA | Slow-speed contra-angle | 6 |
| 1S 021 | 7S | Carbide | Fast-cut | RA | Fast-cutting S version (green ring) | 6 |
| 1SX 021 | 7SX | Carbide | SX-Cut | RA | SX-cut: fast cutting, low vibration | 6 |
| 1SXM 021 | 7SXM | Carbide | SXM-Cut | RA | SXM-cut: fast cutting on a slender neck for visibility | 6 |
| 1SXM 021 | 7SXM | Carbide | SXM-Cut | RA-L (26 mm) | SXM-cut: fast cutting on a slender neck for visibility | 2 |
HP and HP-SH (straight handpiece)3 items
| Busch No. | US No. | Material | Cut | Shank | Best for | Pack |
|---|---|---|---|---|---|---|
| 1 021 | 7 | Carbide | Plain-cut | HP | Straight handpiece: laboratory and denture work | 6 |
| 1 021 | 7 | Steel | Plain-cut | HP | Economical laboratory cutting of acrylics and plaster | 6 |
| 1SXM 021 | 7SXM | Carbide | SXM-Cut | HP | SXM-cut: fast cutting on a slender neck for visibility | 2 |
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). RA-L (latch, 26 mm surgical length). See the Busch Bur Size Chart for head and shank dimensions.
Speed and Technique
In the high-speed handpiece use the FG versions with water spray and a light touch; the RA versions belong in the slow-speed contra-angle for caries removal, where lower speed gives better tactile feedback; HP versions run in the straight handpiece for laboratory work. 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 13485-certified quality management and covered by our Busch warranty.
Clinical Use
- Caries excavation: removing softened dentin from the cavity floor and walls with light, sweeping strokes.
- Access: initial penetration of enamel and the first opening of a cavity or endodontic access.
- Retention and shaping: undercuts and retention grooves where a rounded form is wanted, and smoothing rounded internal line angles.
- Laboratory work: the HP and steel versions hollow out, relieve and adjust acrylic, plaster and wax in the straight handpiece.
At 2.1 mm the No. 7 is a large head for gross excavation, prosthetic and laboratory reduction.
The 7S is Busch’s fast-cutting version (green ring); the 7SX adds the SX-cut geometry that cuts fast with noticeably less vibration (green ring, gold-plated neck); the 7SXM puts the same SX-cut on an extra-slender neck for a clear view of the working area in minimally invasive excavation.
Care and Reconditioning
Busch carbide and steel burs are reusable: clean, disinfect and sterilize them between patients following the manufacturer instructions and replace them once they dull. Our Dental Bur Reprocessing & Sterilization Guide gives the steps for Busch rotary instruments.
Compare With
Related Busch collections: Round Burs, 1SX Cavity Preparation Burs, 1SXM Excavation Burs, Endodontic Burs, and Dental Lab Carbide Burs. For bur numbering, dimensions and ring colors, see the Busch Bur Size Chart and the Dental Bur Color Coding and ISO Guide.
Related resources: US Bur Number Finder · Bur Comparison Chart · Speed Chart · Bur Glossary · Nearby sizes: US No. 5, US No. 6, US No. 8, US No. 9
FAQ
What is the Busch number for a US 7 bur?
Busch No. 1 021 in carbide (FG/RA/HP); Busch No. 1 021 in steel (HP). The 7S is Busch 1S 021; the 7SX is Busch 1SX 021; the 7SXM is Busch 1SXM 021.
What size is a No. 7 bur?
The No. 7 has a 2.1 mm head diameter (ISO size 021) on a round bur head, ISO shape 001 (ball).
What do the letters after No. 7 mean?
The 7S is Busch’s fast-cutting version (green ring); the 7SX adds the SX-cut geometry that cuts fast with noticeably less vibration (green ring, gold-plated neck); the 7SXM puts the same SX-cut on an extra-slender neck for a clear view of the working area in minimally invasive excavation.
Carbide or steel?
Tungsten carbide for enamel, dentin, composite and amalgam in the clinic; the steel No. 7 is the economical choice for acrylics, plaster and other soft materials in the laboratory.
Are Busch No. 7 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.
