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End MillMade in USA

STR-301-10

3 Flute Stub Length Super Tuffy Grade Carbide Rougher

0.3125-in Dia 3-Flute End Mill, 0.5-in LOC, 0.3125-in Shank, 2.5-in OAL

3 Flute Stub Length Super Tuffy Grade Carbide Rougher — STR-301-10
Series photo — representative of the STR-301 family
OAL 2.5″Flute 0.5″Shank Ø0.3125″Cutter Ø0.3125″Square
Scaled drawing — true to this tool's dimensions (inch)
Speeds & FeedsDialed to this exact tool — free
Free CAD & DataSTEP 3DDXF 2DISO CSVCAM library
RobbJack STR Series Super Tuffy grade carbide Ruffer roughing end mill with T-Process honed edges

3 and 4 flute Super Tuffy grade carbide Ruffers for steel and stainless -- T-Process honed roughing tools in stub and standard lengths, inch (STR) and metric (MSTR).

  • Dedicated roughing (Ruffer) geometry in Super Tuffy carbide for cast iron, steel, and stainless steel
  • Four sub-series: STR-301 (3 flute stub), STR-303 (3 flute standard), STR-401 (4 flute stub), STR-404 (4 flute standard), all square end with corner break and 30-degree helix
  • The whole STR Series comes with T-Process honed edges
  • Inch sizes from 1/4" to 3/4" (stub) and 1/4" to 1" (standard); metric MSTR-301/303/401/404 from 6 mm to 20 mm
  • Applications: slotting (3 flute stub), side milling, ramping, and roughing; run dry, wet, cold air, or spray mist
  • Shank flats on 3/8", 1/2", 5/8", 3/4", and 1" sizes (asterisked sizes and all metric tools do not come with flats); order without flats by adding 'NF' to the tool number
  • Roughing tolerances: cutting diameter -.003/-.007 (MSTR -.075/-.180 mm), shank diameter -.0001/-.0002, OAL +/-.060 (MSTR +/-10 mm)
  • Available uncoated or in TiN, TiCN, and AlTiN coatings

From the RobbJack Applications Guide.

About this series

STR / MSTR Super Tuffy Grade Carbide Ruffers

Honed-edge roughers for steel & stainless

The STR Series are Super Tuffy Grade carbide ruffers (roughing end mills) with T-Process honed edges and a 30 degree helix, square end with corner break. Available in 3 flute (STR-301 stub, STR-303 standard) and 4 flute (STR-401 stub, STR-404 standard), uncoated or TiN, TiCN, AlTiN coated, plus metric MSTR equivalents. STR Series comes with T-Process honed edges; any tool can be ordered without flats by adding -NF.

  • 3 flute and 4 flute roughing geometries
  • Square end with corner break, 30 degree helix
  • T-Process honed edge
  • Available uncoated or TiN, TiCN, AlTiN coated
  • Order without flats by adding -NF (metric tools do not have flats)
  • Inch (STR) and metric (MSTR) sizes

Cast iron, steel and stainless steel. Applications: slotting, side milling, ramping and roughing (dry, wet, cold air or spray mist).

Headline spec

Super Tuffy Grade carbide ruffer, T-Process honed edge, 30 degree helix

Best for

  • High-material-removal roughing in steel
  • Stainless steel
  • Slotting and side milling

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
0.3125″
Diameter ToleranceDC tol
-0.0030/-0.0070
Shank DiameterDMM
0.3125″
Length of Cut (LOC)APMX
0.5″
Overall Length (OAL)OAL
2.5″
Corner ChamferCHW
0.010/0.020
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
STR-301 — 3 Flute Stub Length Super Tuffy Grade Carbide Rougher

Cuts these materials

Cast IronSteelStainless Steel

Applications

SlottingSide MillingRampingRoughingDryWetCold AirSpray Mist

Features

T-Process Hone

See it run

Tolerances

TypeMinMax
Cutting Diameter-0.003-0.007
Length of Cut+0.030
Overall Length+0.06-0.06
Shank Diameter-0.0001-0.0002
Starting at$100.75

Made & shipped in the USA · lead time confirmed at order. Buy at retail or through your distributor.

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

Adds Aluminum Titanium Nitride (AlTiN) · $107.65 — our pick for your material. Choose another finish below.

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Proven in the field

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Finishes (4)

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Starting at

$100.75

Performance guaranteed

More in the STR-301 series

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