Midget Mills® - Ground Rotary Files & Burs

The Original Ground Rotary File

Invented by Rollin M. Severance in 1931, Midget Mills revolutionized precision deburring and finishing operations.

Severance Midget Mills are precision ground rotary files designed for deburring, finishing, and shaping operations. Unlike stamped or milled burs, each Midget Mill is individually ground to exacting tolerances, ensuring consistent performance and extended tool life.

"We are the originators; we have been copied but not surpassed."

Ordering Tip

All tools are ordered by their EDP Number (Electronic Data Processing). Find your tool in the tables below and use the EDP number when placing orders.

Key Features

Precision ground flutes
Available in 24 shapes (A-Z, FL)
HSS and Carbide options
1/4" standard shank
Resharpenable
Made in USA

Midget Mills® Identification System

Midget Mills are identified by a three-letter "tool number" that describes the tool's diameter, length, and shape.

First Letter - Diameter

A - 1/8"
B - 3/16"
C - 1/4"
D - 5/16"
E - 3/8"
F - 7/16"
G - 1/2"
H - 9/16"
I - 5/8"
J - 3/4"
K - 7/8"
L - 1"

Second Letter - Length

A - 1/8"
C - 1/4"
E - 3/8"
G - 1/2"
I - 5/8"
J - 3/4"
L - 1"
N - 1-1/4"
P - 1-1/2"
R - 1-3/4"
S - 2"
X - 4"

Third Letter - Shape

A - Cylindrical Square End
B - Ball
C - Cylindrical Rounded
D - Cylindrical w/Radius
E-M - Tapered (various angles)
N - Inverted Cone
P - Pear
Q - Olive
R - Tree (Radius Nose)
S - Tree (Small Radius)
T - Tree (Pointed)
U - Concave
V - Convex
W - Radius End Only
X - Double Angle
BI - Bi-Convex
FL - Flame

Example: CJA-EC-W

C = 1/4" diameter | J = 3/4" flute length | A = Cylindrical Square End | EC = End Cutting | W = Carbide (Tungsten)

Material Types

H.S.S. Midget Mills

Premium M2 High-Speed Steel hardened to Rockwell 63-65. Ideal for general-purpose deburring on steel, aluminum, brass, and plastics.

Standard cut patterns available

Carbide Midget Mills

Custom tungsten-cobalt carbide blend for extended tool life. Excellent for hardened steels, cast iron, and abrasive materials.

10-20x longer life than HSS

Carbo-Mills

Double-cut carbide burs with aggressive cutting action. Designed for rapid stock removal on all materials.

Cross-cut flute pattern

Sever-Cuts

Super coarse cut pattern specifically designed for aluminum and soft non-ferrous metals. Prevents loading and galling.

For aluminum & soft metals

Shape A - Cylindrical Square End

Cylindrical shape with flat end. The most versatile shape for general deburring, side cutting, and surface finishing. Ideal for flat surfaces, slots, and keyways.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	1/4"	AGA	22930	23280
1/8"	1/2"	AGA-EC	22960	23300
3/16"	3/8"	AIA	22931	23281
3/16"	5/8"	AIA-EC	22961	23301
1/4"	1/2"	AKA	22932	23282
1/4"	3/4"	AKA-EC	22962	23302
5/16"	5/8"	AMA	22933	23283
5/16"	1"	AMA-EC	22963	23303
3/8"	3/4"	AOA	22934	23284
3/8"	1-1/8"	AOA-EC	22964	23304
1/2"	1"	ASA	22935	23285
1/2"	1-1/2"	ASA-EC	22965	23305
5/8"	1-1/4"	AWA	22936	23286
3/4"	1-1/2"	BAA	22937	23287
1"	2"	BIA	22938	23288

EC = Extended Cut (longer flute length)

Shape B - Ball

Spherical head for contoured surfaces, radius blending, and concave areas. Excellent for die work and mold finishing.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	1/8"	BGB	22990	23320
3/16"	5/32"	BIB	22991	23321
1/4"	7/32"	BKB	22992	23322
5/16"	9/32"	BMB	22993	23323
3/8"	11/32"	BOB	22994	23324
1/2"	15/32"	BSB	22995	23325
5/8"	19/32"	BWB	22996	23326
3/4"	23/32"	CAB	22997	23327
1"	31/32"	CIB	22998	23328

Shape C - Cylindrical Rounded End (Ball Nose)

Midget Mill Shape C - Cylindrical Rounded End diagram

Cylindrical body with radiused end. Combines the side-cutting of Shape A with the radius blending of Shape B.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	1/4"	CGC	23000	23330
3/16"	3/8"	CIC	23001	23331
1/4"	1/2"	CKC	23002	23332
5/16"	5/8"	CMC	23003	23333
3/8"	3/4"	COC	23004	23334
1/2"	1"	CSC	23005	23335
5/8"	1-1/4"	CWC	23006	23336
3/4"	1-1/2"	DAC	23007	23337
1"	2"	DIC	23008	23338

Shape D - Cylindrical with Radius End

Cylindrical body with corner radius. Prevents corner digging while maintaining flat-bottom capability.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	1/2"	DKD	23010	23340
3/8"	3/4"	DOD	23011	23341
1/2"	1"	DSD	23012	23342
5/8"	1-1/4"	DWD	23013	23343
3/4"	1-1/2"	EAD	23014	23344

Shape E - Oval (Egg)

Egg-shaped head for blending radii and contoured surfaces. Ideal for die sinking and sculptured work.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	5/16"	EIE	23020	23350
1/4"	3/8"	EKE	23021	23351
5/16"	1/2"	EME	23022	23352
3/8"	5/8"	EOE	23023	23353
1/2"	7/8"	ESE	23024	23354
5/8"	1-1/8"	EWE	23025	23355
3/4"	1-5/16"	FAE	23026	23356

Shape F - Tree (Radius End)

Tapered body with radiused end. For contour blending and tapered cavities with smooth bottom finish.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	3/8"	FGF	23030	23360
3/16"	1/2"	FIF	23031	23361
1/4"	5/8"	FKF	23032	23362
3/8"	3/4"	FOF	23033	23363
1/2"	1"	FSF	23034	23364
5/8"	1-1/4"	FWF	23035	23365
3/4"	1-1/2"	GAF	23036	23366

Shape G - Tree (Pointed End)

Tapered body with pointed end. For reaching into corners and V-grooves with aggressive cutting action.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	3/8"	GGG	23040	23370
3/16"	1/2"	GIG	23041	23371
1/4"	5/8"	GKG	23042	23372
3/8"	3/4"	GOG	23043	23373
1/2"	1"	GSG	23044	23374
5/8"	1-1/4"	GWG	23045	23375
3/4"	1-1/2"	HAG	23046	23376

Shape H - Flame

Flame-shaped head for intricate work and detailed finishing. Excellent for tight areas and fine detail work.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	7/16"	HIH	23050	23380
1/4"	9/16"	HKH	23051	23381
3/8"	13/16"	HOH	23052	23382
1/2"	1-1/16"	HSH	23053	23383

Shape I - Tapered (12° C/L Angle)

Midget Mill Shape I - 12 Degree Tapered Cone diagram

Cone shape mills having 12° C/L angle. For precision tapered work and gradual angle transitions.

Head Dia.	Flute Length	Nose	Tool Name	HSS EDP
1/4"	5/16"	1/16"	CDI	23113
3/8"	1/2"	3/32"	EGI	23114
3/8"	3/4"	1/32"	EJI	23115
1/2"	5/8"	9/64"	GII	23116
1/2"	1"	3/64"	GLI	23117
5/8"	3/4"	3/16"	IJI	23118
3/4"	9/16"	5/16"	JHI	23119

Shape J - 60° Included Angle Cone

Midget Mill Shape J - 60 Degree Cone diagram

60° included angle cone for countersinking, chamfering, and deburring holes.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	3/16"	JKJ	23060	23390
3/8"	9/32"	JOJ	23061	23391
1/2"	3/8"	JSJ	23062	23392
5/8"	15/32"	JWJ	23063	23393
3/4"	9/16"	KAJ	23064	23394

Shape K - 90° Included Angle Cone

Midget Mill Shape K - 90 Degree Cone diagram

90° included angle (45° per side) for standard countersinking and chamfering applications.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	1/8"	KKK	23070	23400
3/8"	3/16"	KOK	23071	23401
1/2"	1/4"	KSK	23072	23402
5/8"	5/16"	KWK	23073	23403
3/4"	3/8"	LAK	23074	23404

Shape L - Inverted Cone (Bevel)

Midget Mill Shape L - Inverted Cone diagram

Inverted taper for deburring back side of holes, undercuts, and reverse chamfering.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	3/32"	LKL	23080	23410
3/8"	5/32"	LOL	23081	23411
1/2"	7/32"	LSL	23082	23412
5/8"	9/32"	LWL	23083	23413
3/4"	11/32"	MAL	23084	23414

Shape M - Cone (Pointed End)

14° included angle cone with sharp point. For engraving, scribing, and precision V-groove work.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	1/2"	MIM	23090	23420
1/4"	11/16"	MKM	23091	23421
3/8"	1"	MOM	23092	23422
1/2"	1-3/8"	MSM	23093	23423

Shape N - Inverted Taper (Radius End)

Midget Mill Shape N - Inverted Taper diagram

Inverted taper with radiused end for undercuts and back chamfering with smooth finish.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	3/8"	NKN	23100	23430
3/8"	1/2"	NON	23101	23431
1/2"	5/8"	NSN	23102	23432
5/8"	3/4"	NWN	23103	23433

Shape P - Pear (Bud)

Pear or bud shaped head for blend work and contoured surfaces requiring smooth transitions.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	5/16"	PIP	23110	23440
1/4"	7/16"	PKP	23111	23441
3/8"	5/8"	POP	23112	23442
1/2"	13/16"	PSP	23113	23443
5/8"	1"	PWP	23114	23444

Shape Q - Olive

The very useful olive-shaped mills. Ideal for blending contours, smoothing inside corners, and finishing curved surfaces.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	5/16"	BDQ	23032	23372
1/4"	3/8"	CEQ	—	23373
1/4"	7/16"	CFQ	23033	—
5/16"	1/2"	DGQ	23034	—
3/8"	5/8"	EIQ	23035	23374
3/8"	3/4"	EJQ	23036	—
1/2"	7/8"	GKQ	23037	23375
5/8"	1"	ILQ	23038	23376
3/4"	1"	JLQ	23039	23377
1"	1-3/8"	LOQ	23040	—

Shape R - Tree (Radius Nose)

Tree-shape mills with rounded noses. Excellent for reaching into cavities while providing smooth bottom finish.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/8"	7/16"	AFR	23041	23345
3/16"	5/16"	BDR	23042	—
3/16"	1/2"	BGR	23043	—
1/4"	3/8"	CER	23044	—
1/4"	1/2"	CGR	—	23346
1/4"	3/4"	CJR	23045	23348
1/4"	1"	CLR	23046	—
3/8"	7/16"	EFR	23047	—
3/8"	3/4"	EJR	23048	23349
3/8"	1"	ELR	23049	—
1/2"	3/4"	GJR	23078	23351
1/2"	1"	GLR	23050	23352
1/2"	1-1/8"	GMR	23051	—
5/8"	5/8"	IIR	23052	—
5/8"	1"	ILR	—	23353
5/8"	1-1/8"	IMR	23053	—
3/4"	3/4"	JJR	23054	—
3/4"	1"	JLR	23055	23354
3/4"	1-1/4"	JNR	23056	23355
3/4"	1-1/2"	JPR	—	23356
3/4"	1-5/8"	JQR	23057	—
1-1/8"	1-3/4"	MRR	23058	—
1-1/4"	2"	NSR	23059	—

Shape S - 14° Taper (Radius End)

Midget Mill Shape S - 14 Degree Taper diagram

14° included angle taper with radius end. Combines reach with smooth bottom finishing capability.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
3/16"	5/8"	SIS	23120	23450
1/4"	7/8"	SKS	23121	23451
3/8"	1-1/8"	SOS	23122	23452
1/2"	1-1/2"	SSS	23123	23453

Shape T - Tree (Pointed)

Tree-shape mills with pointed noses. For reaching into corners and V-shaped cavities with aggressive cutting action.

Head Dia.	Flute Length	Tool Name	HSS EDP	Carbide EDP
1/4"	1/2"	CGT	23069	23357
1/4"	5/8"	CIT	—	23358
1/4"	3/4"	CJT	23070	23359
5/16"	3/4"	DJT	—	23360
3/8"	5/8"	EIT	23071	—
3/8"	3/4"	EJT	23072	23361
1/2"	3/4"	GJT	23073	23362
1/2"	1"	GLT	23074	23363
1/2"	1-1/8"	GMT	23075	—
5/8"	1"	ILT	23076	23364
3/4"	1"	JLT	23077	23365
3/4"	1-1/2"	JPT	—	23366

Shape U - Concave Radius

Concave radius mills with cutting teeth on radius only. For creating and finishing concave radii and blending operations.

Head Dia.	Flute Length	Radius	Tool Name	HSS EDP	Carbide EDP
1/4"	1/8"	3/32"	CAU	23186	—
1/4"	3/16"	3/16"	CBU	23187	—
5/16"	3/16"	3/32"	DBU	23189	—
3/8"	1/8"	1/16"	EAU	23190	—
3/8"	3/16"	1/8"	EBU	23191	—
3/8"	1/4"	3/16"	ECU	23192	—
3/8"	5/16"	1/4"	EDU	23193	—
7/16"	1/4"	5/32"	FCU	23194	—
1/2"	1/4"	3/16"	GCU	23195	23421
1/2"	5/16"	1/4"	GDU	23196	23422
1/2"	3/8"	5/16"	GEU	23197	23423
1/2"	7/16"	3/8"	GFU	23198	23424
5/8"	1/2"	7/16"	IGU	23199	—
3/4"	3/8"	1/4"	JEU	23200	—
3/4"	7/16"	5/16"	JFU	23201	—
3/4"	1/2"	3/8"	JGU	23202	—
3/4"	5/8"	1/2"	JIU	23203	—
7/8"	5/8"	7/16"	KIU	23204	—
7/8"	3/4"	5/8"	KJU	23205	—

Shape V - Convex Radius

Convex radius mills with cutting teeth on the radius only. For creating convex radii and blending curved surfaces.

Head Dia.	Flute Length	Radius	Tool Name	HSS EDP
1/4"	3/8"	1/4"	CEV	23206
5/8"	7/16"	1/4"	IFV	23207
3/4"	1/2"	1/2"	JGV	23208
1"	3/16"	3/32"	LBV	23209
1-1/4"	7/8"	5/8"	NKV	23210

Shape W - Wheel (Disc)

Disc-shaped head for slotting, grooving, and reaching into narrow channels.

Head Dia.	Thickness	Tool Name	HSS EDP	Carbide EDP
3/8"	3/32"	WOW	23130	23460
1/2"	1/8"	WSW	23131	23461
5/8"	3/16"	WWW	23132	23462
3/4"	1/4"	XAW	23133	23463

Shape X - Double Angle

Convex shape mills combining forward and reverse angles. Forward angle is given first, followed by reverse angle. Angles are given with centerline. Special angles available at nominal extra charge.

Head Dia.	Head Length	Angle A	Angle B	Tool Name	HSS EDP
1/4"	3/8"	80°	10°	CEX	23217
5/8"	5/8"	40°	20°	IIX	23218
3/4"	1/2"	120°	60°	JGX	23219
1"	3/4"	90°	30°	LJX	23220
1/4"	1/4"	20°	20°	CCX	23221
5/16"	1/4"	30°	30°	DCX	23222
3/8"	1/4"	60°	60°	ECX	23223
1/2"	1/4"	50°	50°	GCX	23224
5/8"	1/4"	60°	60°	ICX	23225
1"	1/4"	90°	90°	LCX	23226
1-1/2"	1/4"	60°	60°	PCX-30	23227
1-1/2"	1/4"	90°	90°	PCX-45	23228
1-1/2"	1/4"	120°	120°	PCX-60	23229

Shape BI - Bi-Convex

Convex shape mills with cutting teeth on the radius only. Different from Shape X which has dual angles - Shape BI provides smooth convex cutting action for blending and finishing operations.

Head Dia.	Head Length	Tool Name	HSS EDP
3/16"	5/16"	BIRU	23230
1/4"	3/8"	CJCU	23231
1/4"	5/8"	CLRU	23232
1/4"	3/4"	CLTU	23233
5/16"	5/8"	DMRU	23234
3/8"	1/2"	ELCU	23235
3/8"	3/4"	ELTU	23236
1/2"	1/2"	GKCU	23237

Shape FL - Flame

A very handy shape for blending operations. The flame shape provides excellent access to contoured surfaces and tight radii.

Head Dia.	Flute Length	Tool Name	Carbide EDP	Carbo-Mill EDP
1/4"	5/8"	CIFL-W	23367	22415
5/16"	3/4"	DJFL-W	23368	22569
1/2"	1-1/4"	GNFL-W	23369	22570
5/8"	1-7/16"	IOFL-W	23370	22571
3/4"	1-5/8"	JQFL-W	23371	22572

Long Shank Midget Mills

Extended reach tools for deep cavity and hard-to-access deburring operations.

Long Shank Midget Mills feature special flute geometry optimized for extended reach applications. Standard long shank length is 8" with 1/4" shank diameter. Other shank lengths available upon request.

Long Shank Specifications

Shank Diameter: 1/4"
Shank Length: 8" (standard)

Feature: Special Flute Geometry
Reference #: 51926

Long shank versions are available for most standard shapes. Contact us for specific shape availability and custom shank lengths.

Custom Lengths Available

Need a different shank length? We can manufacture long shank tools to your specifications.

Request Quote

Pitch/Cut Number Reference

Midget Mills are available in various cut patterns (pitch). The standard cut is optimized for general use. Fine cuts provide smoother finishes; coarse cuts offer faster stock removal.

Cut Number	Description	Application
Standard	Medium pitch, right-hand spiral	General purpose deburring on steel, stainless, brass
Fine	Closer pitch spacing	Finishing work, smooth surface requirements
Coarse	Wider pitch spacing	Rapid stock removal, soft materials
Sever-Cut	Super coarse, wide chip clearance	Aluminum, zinc, copper, soft non-ferrous metals
Double Cut	Cross-hatch pattern (Carbo-Mills)	Aggressive cutting, all materials

Ordering Special Cuts

To order non-standard cuts, add the suffix to the tool name:

-F for Fine cut
-C for Coarse cut
-SC for Sever-Cut

Cut Numbers by Tool Diameter

Standard pitch will always be supplied unless otherwise specified. If an unlisted pitch is required, order by cut number.

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	—

*Super Coarse cuts are recommended for aluminum and other nonferrous materials for heavy, fast stock removal.

Technical Data & Speed/Feed Recommendations

The following guidelines will help you achieve optimal performance from your Midget Mills. Actual speeds and feeds may vary based on material hardness, machine rigidity, and specific application requirements.

HSS Midget Mills (M2 Steel)

Material	SFM	Feed/Tooth
Aluminum	300-500	.002-.004"
Brass/Bronze	200-300	.001-.003"
Mild Steel	80-120	.001-.002"
Stainless Steel	40-80	.0005-.001"
Cast Iron	60-100	.001-.002"

Carbide Midget Mills

Material	SFM	Feed/Tooth
Aluminum	500-1000	.002-.005"
Brass/Bronze	300-500	.001-.003"
Mild Steel	200-400	.001-.002"
Stainless Steel	100-200	.0005-.001"
Hardened Steel (40-50 HRC)	50-100	.0003-.0005"

Coolant

Use flood coolant or mist for best results. Air blast acceptable for aluminum and non-ferrous materials.

Rotation

Clockwise rotation (conventional). Use die grinders, flexible shafts, or CNC machines rated for the required RPM.

Cut Selection

Coarse cuts (8-10 pitch) for soft materials. Fine cuts (14-16 pitch) for finishing and hard materials.

Safety

Always wear safety glasses. Secure workpiece firmly. Never exceed maximum RPM for tool diameter.

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Regrind Service

Save up to 70% by resharpening your Midget Mills. We restore them to factory specs.

Learn More

Need Help Selecting the Right Midget Mill?

Our application engineers can help you choose the optimal shape, material, and cut for your specific operation.

Contact Us 989-777-5500