Carbide Burr Cut Types Explained
Single cut, double cut, super coarse, fine double cut and end cut: what each flute pattern does, which metal it suits, and how to order the pitch you want
Shape Says Where, Cut Says How
The shape of a rotary burr decides where it can reach. The cut decides how it removes metal: how big the chip is, how fast the tool works, what finish it leaves and whether it loads up in soft material. Two burrs of the same shape and size can behave like different tools once the flute pattern changes.
Four things define a cut. The number of flutes, the pitch (spacing between flute edges), the direction of the spiral, and whether a second set of flutes is ground across the first. Severance grinds every pattern from the solid on both high speed steel and tungsten carbide, so the same choice applies across the Midget Mills®, Carbo-Mills™ and Sever-Cuts™ lines.
Published November 3, 2026.
Quick picks
- Steel, stainless, cast iron, heavy removal: double cut Carbo-Mills™
- Steel, finishing and edge control: single cut Midget Mills®
- Aluminum, brass, zinc, plastics: super coarse Sever-Cuts™
- Die and mold finishing: fine double cut Di-Car Mills™
- Plunging or flat bottoms: any pattern with the -EC end cut
Single Cut (Standard Spiral)
A single cut burr has one set of flutes running in a right-hand spiral around the head. Each flute takes a continuous chip, so the tool cuts smoothly, follows an edge predictably and leaves the best finish of the production patterns. It is the pattern most machinists mean when they say "a standard burr".
Single cut suits deburring, chamfering and finishing on carbon steel, stainless steel, cast iron and most bronze and brass. It is also the better choice when the burr is hand-held and the operator needs to feel the cut. The long chip is the trade-off: in gummy material it can wrap the tool, and on heavy stock removal a double cut is faster.
Severance single cut tools: HSS Midget Mills® (right-hand spiral with a light chip breaker), carbide Midget Mills® (tool number suffix -W) and Ecarno-Mills™, the spiral-flute line sold under the industry SA to SN shape codes.
Double Cut (Cross Cut, Diamond Cut)
A double cut burr starts as a single cut and then has a second set of flutes ground across the first at an opposing angle. The result is a field of small diamond-shaped teeth. Each tooth takes a short chip, so the swarf comes off as fine chips instead of long curls, the tool loads less and it cuts faster for the same spindle speed.
Double cut is the choice for heavy stock removal on ferrous metals that do not work-harden: weld dressing, casting clean-up, cutting back flash and opening up holes. The many small teeth also break up the harmonics that make a single cut chatter when it is pushed hard, which is why the pattern is easier to control under a die grinder on a big part. The finish is rougher than a single cut, so a finishing pass with a single cut or a fine pattern often follows.
Severance introduced the double cut pattern and sells it as Carbo-Mills™: tungsten carbide, 1/4″ shank, in the common cylinder, ball, radius-end, tree, cone and flame shapes, with end-cutting versions for plunge work. The Carbo-Mills™ EDP list has every size.
Super Coarse (Aluminum Cut)
Aluminum, zinc die castings, copper, brass, magnesium and most plastics defeat a standard burr the same way: the chip welds into the flutes, the tool stops cutting and the part smears. The fix is fewer, deeper flutes with wide-open chip spaces so the chip leaves the tool before it can pack. That is the super coarse pattern.
Severance Sever-Cuts™ are the super coarse line: tungsten carbide only, 1/4″ shank, shapes A, B, C, Q, R, L and H in 1/4″ to 3/4″ head diameters. They remove soft material fast and leave a medium finish. They are not a general-purpose tool: the pattern is designed for soft, gummy materials, so keep them for non-ferrous work and use a double cut on steel. The full size list is on the Sever-Cuts™ EDP page.
Fine Double Cut and Herringbone
At the other end of the scale, an extra-fine double cut gives a grinding-wheel finish from a rotary tool. The teeth are small enough that the burr can replace mounted stones and points in die and mold finishing, polishing preparation and light stock removal on hardened steel, while cutting rather than rubbing. The herringbone variant arranges the two flute sets so the chip is pushed to the ends of the head instead of the middle.
Di-Car Mills™ are the Severance fine double cut and herringbone tools, on 1/4″ shanks in flat end, radius end and ball nose forms. The carbide hand file guide covers the hand-held side of the same job.
End Cut (-EC)
End cutting is not a pitch but it changes what a cut can do. A standard burr has flutes on the periphery only, so the end is a blank. Adding flutes across the end face lets the tool plunge straight into a surface, finish the floor of a pocket or square up a face without tipping the tool. Severance adds the suffix -EC to the tool number: CJA-EC-W is a 1/4″ carbide cylinder with 3/4″ flute length and an end cut. Ecarno-Mills™ SB and SN-82 are the end-cutting versions of the SA cylinder and SN inverted cone.
Pitch Numbers and How to Order a Cut
Within the single cut family, pitch sets how many teeth the head carries. Finer pitch means more, smaller teeth: smoother finish, slower removal, better on hard materials. Coarser pitch means fewer, larger teeth: faster removal and more chip room, better on soft materials. Severance supplies the standard pitch unless the order says otherwise. To order another pitch, add a suffix to the tool name:
- -F fine cut
- -C coarse cut
- -SC super coarse Sever-Cut pattern (carbide)
Each pitch also has a cut number that depends on head diameter, so a 1/4″ fine cut and a 1″ fine cut are not the same tooth count. If a drawing calls out a specific cut number, order by that number.
| Head diameter | Fine | Standard | Coarse | Super coarse |
|---|---|---|---|---|
| 3/32″ | 2 | 3 | 5 | — |
| 1/8″ | 3 | 4 | 5 | — |
| 3/16″ | 3 | 5 | 6 | — |
| 1/4″ | 4 | 5 | 7 | 4 |
| 5/16″ | 4 | 6 | 7 | — |
| 3/8″ | 4 | 6 | 8 | 6 |
| 7/16″ | 5 | 6 | 8 | — |
| 1/2″ | 5 | 7 | 9 | 8 |
| 9/16″ | 5 | 7 | 9 | — |
| 5/8″ | 5 | 7 | 9 | 10 |
| 3/4″ | 6 | 8 | 10 | 12 |
| 7/8″ | 6 | 8 | 10 | — |
| 1″ | 6 | 8 | 10 | 16 |
| 1-1/8″ | 6 | 9 | 11 | — |
| 1-1/4″ | 6 | 9 | 11 | — |
| 1-1/2″ | 7 | 9 | 12 | — |
Cut numbers from Severance Catalog 101. Super coarse is recommended for aluminum and other non-ferrous materials where heavy, fast stock removal is wanted.
Which Cut for Which Material
| Material | Stock removal | Finishing | Severance line |
|---|---|---|---|
| Carbon and alloy steel | Double cut | Single cut, standard or fine | Carbo-Mills™, Midget Mills® |
| Stainless steel | Double cut, carbide | Single cut, fine | Carbo-Mills™, carbide Midget Mills® |
| Cast iron | Double cut | Single cut, standard | Carbo-Mills™, Midget Mills® |
| Hardened steel, die and mold | Fine double cut | Fine double cut, herringbone | Di-Car Mills™ |
| Aluminum, magnesium, zinc die castings | Super coarse | Super coarse or coarse single cut | Sever-Cuts™, Midget Mills® -C |
| Brass, bronze, copper | Super coarse or coarse | Single cut, standard | Sever-Cuts™, Midget Mills® |
| Plastics, fiberglass, composites | Super coarse | Coarse single cut | Sever-Cuts™, Midget Mills® -C |
Speed matters as much as cut. A coarse pattern in soft material runs at the high end of the range; a fine pattern in hardened steel runs at the low end with light pressure. The rotary file speed and feed charts give RPM by head diameter and material, and HSS vs carbide explains when the carbide version earns its price.
Cut Type Questions
A single cut burr has one set of spiral flutes. It takes a longer chip, leaves a smoother finish and gives the operator more control, so it is the general-purpose and finishing pattern. A double cut burr adds a second set of flutes ground across the first, which breaks the chip into small pieces, cuts faster, grabs less and runs with less chatter, at the cost of a rougher finish. Severance introduced the double cut pattern and sells it as Carbo-Mills™.
A super coarse aluminum cut. Standard and double cut flutes pack with aluminum and stop cutting. Severance Sever-Cuts™ use wide-open super coarse flutes that clear the chip, and they also suit brass, copper, zinc die castings, magnesium and plastics.
They order a non-standard pitch: -F is fine cut, -C is coarse cut and -SC is the super coarse Sever-Cut pattern. Standard pitch is supplied when no suffix is given. Each pitch also has a cut number that depends on the head diameter, listed in the table above.
Yes. Severance Midget Mills®, Carbo-Mills™ and Sever-Cuts™ are ground from the solid and can be reground to the original pattern. The Severance regrind service accepts HSS and carbide rotary files from 1/16″ to 3″ diameter, including other brands, with a 1 to 3 week turnaround.