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End MillMade in USA

MSTR-404-12

4 Flute Standard Length Metric Super Tuffy Grade Carbide Rougher

12mm Dia 4-Flute Metric End Mill 25mm LOC, 12mm Shank, 83mm OAL

OrderingMSTR-404-12·Uncoated·$278.30Change finish

4 Flute Standard Length Metric Super Tuffy Grade Carbide Rougher — MSTR-404-12
Series photo — representative of the MSTR-404 family
OAL 83 mmFlute 25 mmShank Ø12 mmCutter Ø12 mmSquare
Scaled drawing — true to this tool's dimensions (mm)
Speeds & FeedsDialed to this exact tool — free
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

MSTR Metric Super Tuffy Grade Carbide Ruffers

Metric honed-edge roughers for steel & stainless

MSTR is the metric variant of the STR Series: Super Tuffy Grade carbide ruffers with T-Process honed edge and 30 degree helix, in 3 flute (MSTR-301, MSTR-303) and 4 flute (MSTR-401, MSTR-404) geometries, uncoated or TiN, TiCN, AlTiN coated, 6-20 mm sizes. Metric tools do not have flats.

  • 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
  • Metric sizes 6 mm to 20 mm; metric tools do not have flats

Cast iron, steel and stainless steel. Slotting, side milling, ramping and roughing.

Headline spec

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

Best for

  • Metric high-removal roughing
  • Steel and stainless steel

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
12 mm
Diameter ToleranceDC tol
-0.075/-0.180
Shank DiameterDMM
12 mm
Length of Cut (LOC)APMX
25 mm
Overall Length (OAL)OAL
83 mm
Corner ChamferCHW
0.50MM/0.80MM
Number of FlutesNOF
4
Helix AngleFHA
30°
Helix HandFHH
Right-hand
Cut Direction
Right-hand cut
End Type
Square End
Center Cutting
Yes — plunges
Series
MSTR-404 — 4 Flute Standard Length Metric Super Tuffy Grade Carbide Rougher

Cuts these materials

Cast IronSteelStainless Steel

Applications

Side MillingRampingRoughingDryWetCold AirSpray Mist

Features

T-Process Hone

See it run

Tolerances

TypeMinMax
Cutting Diameter-0.075-0.18
Length of Cut+0.5+1.5
Overall Length+1-1
Shank Diameter-0.002-0.005

Choose the finish(4 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$278.30

Part MSTR-404-12

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 MSTR-404-12 · Uncoated · $278.30

Calculate Speeds & FeedsDownload ISO 13399 data (.csv)

Uncoated

$278.30

MSTR-404-12

Starting speeds & feeds for the MSTR-404-12

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 MSTR-404-12
MaterialOperationSFMRPMFeed (IPM)Chip load / toothDOC (in)WOC (in)
Gray IronRoughing — full slot5004,04397.00600.2362.4724
4140 SteelRoughing — full slot2201,77910.7.00150.2362.4724
303 StainlessRoughing — full slot5004,04337.2.00230.2362.4724

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 MSTR-404 series

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