Dental bur numbers explained: US numbers, ISO 6360 codes and shanks

Updated October 19, 2026

A bur order is usually a list of numbers: a box of 330s, some 557s, a few 856 diamonds. Two numbering systems are in use, and the same shape can carry different numbers depending on whose catalog you read. This guide explains both systems, the three shank types, and the color bands on diamonds, so a number on an old invoice can be matched to the right bur.

The two systems

In the United States, carbide burs are usually named by a shape number from the traditional American (S.S. White) system: 330, 245, 557, 169L. The number names the shape and size together, and the shank is written in front of it: FG 330 is a 330 on a friction-grip shank.

The international system is ISO 6360, a number coding system for dental rotary instruments. It describes a bur in five groups of three digits, in this order: the material of the working part, the shank type and length, the shape, a specific characteristic of the shape (such as a cross-cut or a particular grit), and the nominal diameter of the head. European makers print these codes on their packaging, often in a shortened form.

Reading an ISO code

Take a Komet diamond labeled 813 314 016. Its three groups read: shape 813, shank 314 (friction grip, standard length), diameter 016. The full ISO code would also name the material at the front, for example 806 for a diamond with an electroplated bond or 500 for tungsten carbide.

The last group is the one most often seen on its own: the head diameter in tenths of a millimeter. A size 016 head is 1.6 mm across; size 010 is 1.0 mm. Many diamonds are sold under the maker's shape number with the ISO size after a point, which is why you will see names like NeoDiamond #856.016 coarse round-end taper: shape 856, 1.6 mm. The same disposable diamond in a smaller head is the 856.014.

The shank codes that come up most:

• 314: friction grip (FG), standard length, for high-speed handpieces
• 204: right-angle latch (RA, also called latch-type or contra-angle), for slow-speed contra-angles
• 104: straight handpiece (HP), the long shank used in lab and some surgical work

Common US carbide numbers

These are the shape families most practices reorder. The number range is the same family in increasing sizes.

• Round (¼ to 11): the FG2 round carbide for access and caries removal at high speed; the RA4 round carbide for slow-speed excavation.
• Pear (330 to 333): the FG330 pear carbide, a standard for conservative preparations. The longer pear, 245, is the classic amalgam preparation bur: FG245 carbide.
• Tapered fissure, plain cut (168 to 172, with L for the long version): FG169L tapered fissure.
• Straight fissure, cross-cut (556 to 560): the FG557 straight cross-cut, clinic pack of 100. Cross-cut blades cut faster and leave a rougher surface.
• Tapered fissure, cross-cut (699 to 703): FG701 tapered cross-cut.

A 1 in front of a cross-cut number, as in 1557 or 1701, usually means the round-end version of that shape: FG1557 round-end cross-cut. A suffix such as SL or L means a longer neck or a surgical length, as with the FG557 surgical length.

Diamond grit and color bands

Diamond instruments carry a colored band on the neck that shows the grit, under the color code in ISO 7711-3. The usual sequence, from coarsest to finest, is: black (super coarse), green (coarse), blue or no band (medium), red (fine), yellow (extra fine) and white (ultra fine). Coarse grits remove tooth structure quickly for gross reduction; fine and extra-fine grits finish margins and smooth the preparation. Check the maker's chart for the particle size behind each color, because the exact sizes differ between manufacturers.

Matching an old invoice

When a number on an invoice will not match, check these in order:

1. The shank. The same shape number exists in FG, RA and sometimes HP, and they do not fit the same handpiece.
2. The system. A five- or six-digit number with groups of three is ISO; 330 or 557 is the US system.
3. The size. An ISO size of 016 and 014 are the same shape at different diameters.
4. The pack. Burs come in packs of 5, 10, 25 and clinic packs of 100. Our listings state the pack in the name and the pack column, for example the FG330 in a 100-pack at $150.00 against $17.00 for the 10-pack.

Our search understands catalog numbers with or without the space, so "FG 330", "FG330" and "330 FG" find the same bur. Quick order accepts the same numbers in a pasted list.

A note on carbide versus diamond

Carbide burs cut with blades and tend to leave a smoother surface at the same speed; diamonds abrade with bonded particles and are the usual choice for crown and veneer preparation and for cutting ceramics. Both are single-patient or multi-use depending on the product, and reusable burs must be cleaned and sterilized between patients according to the manufacturer's instructions.

Everything is in Burs & Diamonds, listed by number. For how ordering works here, see ordering without a rep.