Skip to content
End MillMade in USA

B-203-12

2 Flute Tuffy Ball End Standard Length Tuffy Grade Carbide End Mill

0.375-in Dia 2-Flute End Mill, 0.875-in LOC, 0.375-in Shank, 2.5-in OAL with Weldon Flats

OrderingB-203-12·Uncoated·$115.65Change finish

2 Flute Tuffy Ball End Standard Length Tuffy Grade Carbide End Mill — B-203-12
Series photo — representative of the B-203 family
OAL 2.5″Flute 0.875″Shank Ø0.375″Cutter Ø0.375″Ball
Scaled drawing — true to this tool's dimensions (inch)
Speeds & FeedsDialed to this exact tool — free
Free CAD & DataSTEP 3DDXF 2DISO CSVCAM library
RobbJack B-203-12 two-flute Tuffy grade carbide ball end mill, 3/8-inch diameter

Tuffy grade carbide ball end mills — 2, 3 and 4 flute, from 1/16-inch to 3/4-inch

  • B-203 2 flute ball end, standard length: fourteen inch sizes from 1/16-in to 3/4-in on 1-1/2-in to 4-in OALs
  • MB-203 metric line: 2 mm to 20 mm ball diameters, 38–104 mm overall lengths
  • B-300 3 flute ball end stub length and B-330 3 flute standard length: 1/8-in to 3/4-in, listed in the Steel & Hi-Temp Alloys section
  • B-440 4 flute ball end standard length with 40-degree helix (also MB-440 metric) for hardened-material finishing
  • Tuffy sub-micrograin carbide grade across the family
  • Coatings available on every size: TiN (-T), TiCN (-C), AlTiN (-A) and DLC (-DLC)

From the RobbJack Applications Guide.

About this series

B / MB Tuffy Grade Carbide Ball End Mills

Honed-edge ball end mills for 3-D work in steel & alloys

The B Series are Tuffy Grade carbide ball end mills with a T-Process honed edge for die/mold and 3-D machining. Available in 3 flute (B-300 stub and B-330 standard, 30 degree helix) and 4 flute (B-440 standard, 40 degree helix), uncoated or TiN, TiCN, AlTiN coated, plus metric MB equivalents.

  • 3 flute (B-300/B-330) and 4 flute (B-440) ball end geometries
  • 30 degree (3 flute) and 40 degree (4 flute) helix
  • T-Process honed edge
  • Available uncoated or TiN, TiCN, AlTiN coated
  • Inch (B) and metric (MB) sizes

Cast iron, steel, stainless steel and super alloys. Applications: slotting, side milling, helical interpolation, conventional, ramping, high-performance 3-D, roughing, semi-finishing and finishing.

Headline spec

Tuffy Grade carbide ball end mill with T-Process honed edge

Best for

  • 3-D and die/mold machining
  • Steel, stainless and super alloys
  • Roughing through finishing

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
0.375″
Diameter ToleranceDC tol
0.0000/-0.0020
Max Cutting DiameterDCX
0.375″
Shank DiameterDMM
0.375″
Length of Cut (LOC)APMX
0.875″
Overall Length (OAL)OAL
2.5″
Corner RadiusRE
0.1875″
Number of FlutesNOF
2
Helix AngleFHA
30°
Helix HandFHH
Right-hand
Cut Direction
Right-hand cut
End Type
Ball End
Center Cutting
Yes — plunges
Series
B-203 — 2 Flute Tuffy Ball End Standard Length Tuffy Grade Carbide End Mill

Cuts these materials

AluminumCopper & BrassMagnesiumCast IronPlasticsWood

Applications

SlottingSide MillingHelical InterpolationConventionalRampingHigh Performance3-DRoughingSemi-FinishingFinishing

See it run

Tolerances

TypeMinMax
Cutting Diameter0-0.003
Length of Cut+0.060
Overall Length+0.06-0.06
Shank Diameter-0.0001-0.0002

Choose the finish(6 options)

Compare →

Each finish is a different part number and price.

Not sure? Compare tool coatings — or leave it uncoated, the most common choice for aluminum.

Uncoated · your price$115.65

Part B-203-12

Made & shipped in the USA · lead time confirmed at order. Test this tool in your spindle at retail, or get it through your RobbJack distributor.

Performance guaranteed. Run it against the tool you use today — if it doesn't beat it, we'll make it right.

Adds B-203-12 · Uncoated · $115.65

Calculate Speeds & Feeds
CADDXF·STEP
Add to Quote
Download ISO 13399 data (.csv)

Proven in the field

See the case studies →

Uncoated

$115.65

B-203-12

Starting speeds & feeds for the B-203-12

Dial in for your machine →

RobbJack's tested starting numbers for this exact tool, from the same engine and the same default machine as the calculator: a 12,000 RPM / 400 IPM / 30 HP machining center, rigid setup, full-depth cut. A faster or smaller spindle changes the RPM and feed — enter yours in the calculator and it re-governs every number.

Starting speeds and feeds for RobbJack B-203-12
MaterialOperationSFMRPMFeed (IPM)Chip load / toothDOC (in)WOC (in)
6061(T4-T6) AluminumRoughing — full slot1,17912,000230.4.00960.3750.3750
6061(T4-T6) AluminumFinishing1,17912,000115.2.00480.3750.0188
Free-Cutting BrassRoughing — full slot7507,64073.3.00480.3750.3750
Free-Cutting BrassFinishing7507,64036.7.00240.3750.0188
AcetalRoughing — full slot1,17912,000230.4.00960.3750.3750
AcetalFinishing1,17912,000115.2.00480.3750.0188

Read before you run

Recommendations are computed starting points based on typical conditions — not guarantees of performance, tool life, or fitness for your application. Machining involves inherent risk: you are solely responsible for safe operation, for verifying every parameter against your machine, spindle, toolholding, workholding, and guarding limits, and for proving all parameters on a test cut before production. RobbJack Corporation assumes no liability for tool breakage, machine damage, scrapped parts, production loss, or personal injury arising from use of these recommendations. By using this calculator you accept RobbJack's Terms & Conditions.

More in the B-203 series

Same series, different size — what changes from this tool is shown in red.