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End MillMade in USA

MTL-303-06

3 Flute Extra Length Metric Tuffy Grade Carbide End Mill

6mm Dia 3-Flute Metric End Mill 32mm LOC, 6mm Shank, 75mm OAL

OrderingMTL-303-06·$166.75

3 Flute Extra Length Metric Tuffy Grade Carbide End Mill — MTL-303-06
Series photo — representative of the MTL-303 family
OAL 75 mmFlute 32 mmShank Ø6 mmCutter Ø6 mmSquare
Scaled drawing — true to this tool's dimensions (mm)
Speeds & FeedsDialed to this exact tool — free
Free CAD & DataSTEP 3DDXF 2DISO CSVCAM library
RobbJack TL-303 3-flute extra length Tuffy grade carbide end mill

3-flute extra-length Tuffy grade square end mills — long flutes for deep side milling, with shank flats on the larger inch sizes.

  • 3 flute square end extra-length Tuffy grade carbide with 30° helix
  • Long flute lengths for deep walls — up to 3" of flute on the 3/4" tool (5" OAL); metric MTL runs up to 75 mm flute on the 20 mm tool (130 mm OAL)
  • Inch sizes 1/8"–3/4" (TL-303); metric sizes 3–20 mm (MTL-303)
  • Shank flats on the 3/8", 1/2", 5/8", and 3/4" inch sizes for secure holding; 1/8"–5/16" and 7/16" sizes and all metric tools do not have flats
  • Rated for side milling, semi-finishing, and finishing — wet, cold air, or spray mist
  • Broad material range: aluminum, copper, magnesium, cast iron, steel, stainless steel, plastics, brass, and wood
  • Tolerances: cutting dia −.001/−.002 at 1/8" and +.001/−.000 from 3/16"–3/4"; shank −.0001/−.0002; flute length +.060/−.000 (MTL cutting dia +.025/−.000 mm from 4–20 mm)
  • Guide cross-reference for chatter on long reaches: consider the FM Series or add Mirror Edge treatment

From the RobbJack Applications Guide.

Lengthened TL-303 3-flute extra length end mill showing the long flute section

About this series

TL / MTL Extra Length Tuffy Grade Carbide End Mills

3 flute extra-length square-end mills for deep-reach work

The TL-303 is a 3 flute, extra-length, square-end Tuffy Grade carbide end mill with a 30 degree helix. MTL-303 is the metric extra-length version (metric tools do not have flats). Available in inch sizes 1/8" to 3/4" and metric sizes 3 mm to 20 mm.

  • Extra length, 3 flute square end, 30 degree helix
  • Inch (TL) and metric (MTL) versions
  • Metric tools do not have flats

Aluminum, copper, magnesium, cast iron, steel, stainless steel, plastics, brass, wood

Headline spec

Extra length, 3 flute, 30 degree helix

Best for

  • Side milling
  • Semi-finishing and finishing

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
6 mm
Diameter ToleranceDC tol
0.025/0.000
Shank DiameterDMM
6 mm
Length of Cut (LOC)APMX
32 mm
Overall Length (OAL)OAL
75 mm
Number of FlutesNOF
3
Helix AngleFHA
30°
Helix HandFHH
Right-hand
Cut Direction
Right-hand cut
End Type
Square End
Center Cutting
Yes — plunges
Series
MTL-303 — 3 Flute Extra Length Metric Tuffy Grade Carbide End Mill

Cuts these materials

AluminumCopper & BrassMagnesiumCast IronSteelStainless SteelPlastics

Applications

Side MillingSemi-FinishingFinishingWetCold AirSpray Mist

See it run

Tolerances

TypeMinMax
Cutting Diameter+0.0250
Length of Cut+0.5+1.5
Overall Length+1-1
Shank Diameter-0.002-0.005
MTL-303-06In stock$166.75
Uncoated · your price$166.75

Part MTL-303-06

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 MTL-303-06 · · $166.75

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Download ISO 13399 data (.csv)

Proven in the field

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Starting at

$166.75

MTL-303-06

Starting speeds & feeds for the MTL-303-06

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 MTL-303-06
MaterialOperationSFMRPMFeed (IPM)Chip load / toothDOC (in)WOC (in)
6061(T4-T6) AluminumRoughing — full slot74312,000216.00600.2362.2362
6061(T4-T6) AluminumFinishing74312,000108.00300.2362.0118
Free-Cutting BrassRoughing — full slot74312,000108.00300.2362.2362
Free-Cutting BrassFinishing74312,00054.00150.2362.0118
AcetalRoughing — full slot74312,000216.00600.2362.2362
AcetalFinishing74312,000108.00300.2362.0118

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 MTL-303 series

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