Busch Bur Measurement Size Chart
Every Busch bur is sized according to the international ISO 6360 numbering system used across the Busch & Co. catalog. The rule is simple: the size number is the maximum head diameter in tenths of a millimeter. A Busch bur in size 010 has a 1.0 mm head; size 023 is 2.3 mm; size 060 is 6.0 mm. This chart converts every standard Busch bur size to millimeters and inches, explains the shank codes, and shows how to read a full ISO number — so you can match any figure in the Busch burs catalog to the exact dimensions you need.
Busch Bur Size to mm Conversion Chart
| ISO Size | Head Ø (mm) | Head Ø (inches) | Typical Use Range |
|---|---|---|---|
| 003 | 0.3 mm | 0.012" | Micro-preparation, retention grooves |
| 005 | 0.5 mm | 0.020" | Fine cavity preparation, endo access |
| 006 | 0.6 mm | 0.024" | Small round burs, fissure work, pediatric |
| 007 | 0.7 mm | 0.028" | |
| 008 | 0.8 mm | 0.031" | |
| 009 | 0.9 mm | 0.035" | |
| 010 | 1.0 mm | 0.039" | |
| 012 | 1.2 mm | 0.047" | Standard operative sizes — excavating, fissure burs, crown cutters |
| 014 | 1.4 mm | 0.055" | |
| 016 | 1.6 mm | 0.063" | |
| 018 | 1.8 mm | 0.071" | |
| 021 | 2.1 mm | 0.083" | Large round burs, finishing burs, surgical instruments |
| 023 | 2.3 mm | 0.091" | |
| 025 | 2.5 mm | 0.098" | |
| 027 | 2.7 mm | 0.106" | |
| 029 | 2.9 mm | 0.114" | Bone cutters, laboratory burs |
| 031 | 3.1 mm | 0.122" | |
| 035 | 3.5 mm | 0.138" | |
| 040 | 4.0 mm | 0.157" | |
| 045 | 4.5 mm | 0.177" | |
| 050 | 5.0 mm | 0.197" | |
| 060 | 6.0 mm | 0.236" | Large lab cutters (HP shank) for plaster, acrylic, alloys |
| 070 | 7.0 mm | 0.276" | |
| 080 | 8.0 mm | 0.315" |
Per the official Busch technical data, working-part diameters range from 0.3–8.0 mm for carbide instruments, 0.5–12.0 mm for steel, and 1.4–6.0 mm for KERA ceramic cutters, with concentricity superior to DIN, EN, and ISO standard requirements.
Busch Shank Types & Dimensions
The middle section of every ISO number identifies the shank. Busch manufactures all shanks to tighter-than-standard tolerances: FG shanks at 1.60 mm +0/−0.010 mm and RA/HP shanks at 2.35 mm +0/−0.016 mm.
| Shank Type | Shank Ø | Overall Length | ISO Code | Handpiece |
|---|---|---|---|---|
| FG (Friction Grip) | 1.60 mm | 19 mm | 314 | High-speed turbine |
| FG x-long | 1.60 mm | 25 mm | 316 | High-speed turbine (deep access) |
| RA / CA (Right Angle) | 2.35 mm | 22 mm | 204 | Contra-angle, low speed |
| RA long | 2.35 mm | 26 mm | 205 | Contra-angle (surgical/deep) |
| RA x-long | 2.35 mm | 34 mm | 206 | Contra-angle (surgical) |
| HP short | 2.35 mm | 34 mm | 103 | Straight handpiece (milling technique) |
| HP (Handpiece) | 2.35 mm | 44.5 mm | 104 | Straight handpiece / laboratory |
| HP long | 2.35 mm | 64.5 mm | 105 | Straight handpiece (extended reach) |
How to Read a Busch ISO Number
Every Busch instrument carries a full ISO 6360 number on its packaging. Example: ISO 500 314 001 001 010 breaks down as:
| Segment | Value | Meaning |
|---|---|---|
| Material | 500 | Tungsten carbide (310 = tool steel, 330 = stainless steel, 806 = diamond-coated) |
| Shank | 314 | FG shank, 1.6 mm Ø, 19 mm length (see shank table above) |
| Head shape | 001 | Round (e.g. 107 = cylinder, 168 = pear, 194 = taper round) |
| Cut type | 001 | Standard cut (e.g. 019 = power SX-cut, 072 = finishing cut, 140 = fine cross-cut) |
| Size | 010 | Head diameter 1.0 mm |
The short Busch figure number (e.g. 1SXM, 21R, 429GX) printed on the shank identifies the same instrument in catalog shorthand — our Bur Comparison Chart cross-references Busch figures against US bur numbers.
Busch Color Ring Codes
Busch marks cut and grit variants with a colored ring on the shank so easily-confused cuts can be identified at a glance:
| Ring | Carbide Cut | Diamond Grit |
|---|---|---|
| Black | — | Very coarse |
| Green | Power cut (high material removal) | Coarse |
| Blue | — | Medium (standard, often unmarked) |
| Red | — | Fine |
| Yellow | Fine finishing cut (16–22 blades) | Extra fine |
| White | Ultra-fine finishing cut (30 blades) | Ultra fine |
Cooling note from the Busch usage recommendations: FG instruments with an overall length above 22 mm or a head diameter above 2 mm may require additional water cooling beyond the standard minimum of 50 ml/min — as may long-shank surgical instruments. Always observe the maximum permissible RPM printed on each Busch package; see our Dental Bur Speed Chart for recommended operating speeds by instrument type.
Find Your Busch Bur by Size
Every product page in our Busch dental burs collection lists the Busch figure number, ISO size, shank type, and pack quantity, so you can order the exact instrument dimension you need. For cross-referencing American bur numbers to Busch figures, use our Bur Comparison Chart; for terminology, see the Dental Bur Glossary; and for reprocessing workflows, see the Bur Reprocessing & Sterilization Guide. Official manufacturer documentation is available on the Busch Burs Catalog page.
