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End MillMade in USA

MNS-401-25

4 Flute Variable Helix Stub Length Metric Solid carbide End Mill for Steels

25mm Dia 4-Flute Metric End Mill Square End Mill 25mm LOC, 25mm Shank, 121mm OAL, 0.5mm Chamfer with Weldon Flats

OrderingMNS-401-25·Aluminum Titanium Nitride (AlTiN)·$821.75Change finish

4 Flute Variable Helix Stub Length Metric Solid carbide End Mill for Steels — MNS-401-25
Series photo — representative of the MNS-401 family
OAL 121 mmFlute 25 mmShank Ø25 mmCutter Ø25 mmSquare
Scaled drawing — true to this tool's dimensions (mm)
Speeds & FeedsDialed to this exact tool — free
Free CAD & DataSTEP 3DDXF 2DISO CSVCAM library
NS Series recommended engagement diagrams: slotting at 1 x diameter width and .5 x diameter depth, profiling at .5 x diameter radial width and 1 x diameter axial depth

4-flute variable-helix Tuffy grade end mills for cast iron and steels to 40 HRc — stub, standard, and long lengths, AlTiN coated, with optional flats for high-torque cuts.

  • 4 flute, variable helix — the variable pitch damps harmonics for stable cuts in cast iron and steel up to 40 HRc hardness
  • Three lengths per diameter: NS-401 stub, NS-402 standard, NS-403 long (e.g. 1/2": 3/4", 1-1/8", and 1-1/2" flute lengths)
  • Inch sizes 3/16"–1"; metric MNS line runs 4–20 mm
  • Every tool AlTiN (aluminum titanium nitride) coated, in flats (-FL) and no-flats versions — 'Slippage? Tool Holder — Add Flats!' for high-torque cuts
  • Protective corner chamfer on every size, .008 to .02 by diameter (metric 0.2–0.5 mm)
  • Guide engagement guidance: slot at 1 × diameter width and .5 × diameter depth; profile at .5 × diameter radial width and 1 × diameter axial depth
  • Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, and finishing — dry or wet
  • Tolerances: NS cutting dia −.001/−.002, shank −.0001/−.0002, flute length +.060/−.000; MNS cutting dia −0.025/−0.050 mm, shank −0.002/−0.005 mm

From the RobbJack Applications Guide.

About this series

MNS Metric Tuffy Grade Carbide End Mills

Metric variable-helix 4-flute tools for titanium, steel & high-temp alloys

MNS is the metric variant of the NS Series: 4-flute variable-helix Tuffy Grade carbide end mills, AlTiN coated, for titanium, steel and high-temp alloys. Available in standard length (MNS-402) in 4-25 mm sizes, with or without flats. NS/MNS speeds & feeds are published for cast iron, steel, tool steel and other alloys.

  • 4 flute, square end
  • Variable helix geometry
  • AlTiN coated
  • Metric sizes 4 mm to 25 mm
  • Available with flats for high-torque cuts

Cast iron, steel, tool steel and high-temp alloys up to 40 HRc; titanium. Slotting, side milling, helical interpolation, ramping, roughing and finishing.

Headline spec

Metric 4-flute variable-helix Tuffy Grade carbide, AlTiN coated

Best for

  • Metric titanium and steel machining
  • High-temp alloys
  • Slotting and profiling

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
25 mm
Diameter ToleranceDC tol
0.001/0.000
Shank DiameterDMM
25 mm
Length of Cut (LOC)APMX
25 mm
Overall Length (OAL)OAL
121 mm
Corner ChamferCHW
0.50MM/0.80MM
Chamfer AngleKCH
45°
Number of FlutesNOF
4
Helix AngleFHA
Variable
Helix HandFHH
Right-hand
Cut Direction
Right-hand cut
End Type
Chamfer
Center Cutting
Yes — plunges
Series
MNS-401 — 4 Flute Variable Helix Stub Length Metric Solid carbide End Mill for Steels

Cuts these materials

Cast IronSteel

Applications

SlottingSide MillingHelical InterpolationRampingHigh PerformanceRoughingSemi-FinishingFinishingDryWetCold AirSpray Mist

See it run

Tolerances

TypeMinMax
Cutting Diameter+0.0010
Length of Cut+0.060
Overall Length+0.06-0.06
Shank Diameter-0.0001-0.0002

Choose the finish(2 options)

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Each finish is a different part number and price.

AlTiN · your price$821.75

Part MNS-401-25

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 MNS-401-25 · Aluminum Titanium Nitride (AlTiN) · $821.75

Calculate Speeds & Feeds
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Download ISO 13399 data (.csv)

Proven in the field

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AlTiN

$821.75

MNS-401-25

Starting speeds & feeds for the MNS-401-25

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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 MNS-401-25
MaterialOperationSFMRPMFeed (IPM)Chip load / toothDOC (in)WOC (in)
Gray IronRoughing — full slot5252,03835.9.00440.6799.9843
Gray IronFinishing5252,03835.9.00440.9843.0246
4140 SteelRoughing — full slot4001,55217.4.00280.6890.9843
4140 SteelFinishing4001,55217.4.00280.9843.0246
303 StainlessRoughing — full slot5502,13526.5.00310.6449.9843
303 StainlessFinishing5502,13526.5.00310.9843.0246

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 MNS-401 series

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