MSTR-303-06
3 Flute Standard Length Metric Super Tuffy Grade Carbide Rougher
6mm Dia 3-Flute Metric End Mill 14mm LOC, 6mm Shank, 57mm OAL
OrderingMSTR-303-06·Uncoated·$106.05Change finish
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
- 6 mm
- Diameter ToleranceDC tol
- -0.075/-0.180
- Shank DiameterDMM
- 6 mm
- Length of Cut (LOC)APMX
- 14 mm
- Overall Length (OAL)OAL
- 57 mm
- Corner ChamferCHW
- 0.25MM/0.50MM
- 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
- MSTR-303 — 3 Flute Standard Length Metric Super Tuffy Grade Carbide Rougher
Cuts these materials
Applications
Features
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| 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.
Part MSTR-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.
Uncoated
$106.05
MSTR-303-06
Starting speeds & feeds for the MSTR-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.
| Material | Operation | SFM | RPM | Feed (IPM) | Chip load / tooth | DOC (in) | WOC (in) |
|---|---|---|---|---|---|---|---|
| Gray Iron | Roughing — full slot | 500 | 8,086 | 72.8 | .00300 | .1181 | .2362 |
| 4140 Steel | Roughing — full slot | 220 | 3,558 | 8.5 | .00080 | .1181 | .2362 |
| 303 Stainless | Roughing — full slot | 500 | 8,086 | 26.7 | .00110 | .1181 | .2362 |
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-303 series
Same series, different size — what changes from this tool is shown in red.
- MSTR-303-08$156.70Ø 8 mmLOC 16 mmOAL 63 mm3 FL
- MSTR-303-10$221.80Ø 10 mmLOC 20 mmOAL 72 mm3 FL
- MSTR-303-12$278.30Ø 12 mmLOC 25 mmOAL 83 mm3 FL
- MSTR-303-16$475.85Ø 16 mmLOC 32 mmOAL 92 mm3 FL
- MSTR-303-20$739.65Ø 20 mmLOC 38 mmOAL 104 mm3 FL
- MSTR-301-06$94.10LOC 8 mmØ 6 mm3 FLOAL 57 mm
- MSTR-301-08$142.05Ø 8 mmLOC 12 mmOAL 63 mm3 FL
- MSTR-301-10$221.80Ø 10 mmOAL 72 mm3 FLLOC 14 mm
- MSTR-301-12$259.70Ø 12 mmLOC 16 mmOAL 83 mm3 FL
- MSTR-301-16$442.40Ø 16 mmLOC 20 mmOAL 92 mm3 FL
- MSTR-301-20$695.15Ø 20 mmLOC 25 mmOAL 104 mm3 FL
- MSTR-401-06$97.154 FLLOC 8 mmØ 6 mmOAL 57 mm