S1-301-16
3 Flute Stub Length C-2 Grade Carbide End Mill
0.5-in Dia 3-Flute End Mill, 0.625-in LOC, 0.5-in Shank, 3-in OAL
OrderingS1-301-16·Uncoated·$139.40Change finish


2, 3 & 4 Flute C-2 Grade Carbide End Mills — stub length workhorses for aluminum and non-ferrous milling
- C-2 grade carbide end mills in stub length — 2 flute (S1-201), 3 flute (S1-301), and 4 flute (S1-401), all square end with 30° helix
- S1-201 inch sizes 1/16"–3/4" cutting diameter; metric MS1-201 2 flute in 2mm–20mm cutting diameters (38mm–92mm OAL)
- Applications: slotting, side milling, helical interpolation — from high performance roughing through semi-finishing and finishing, run dry, wet, cold air, or spray mist
- Materials: aluminum, copper, magnesium, plastics, composites, brass
- Uncoated or Diamond-Like Carbon (DLC) coated — every size in the series is offered in a -DLC version
- S1 tolerances: cutting dia. +.000/−.002 (1/16"–1/4") and +.000/−.003 (9/32"–3/4"); shank dia. −.0001/−.0002; flute length +.030/−.000 (1/16"–5/16") and +.060/−.000 (3/8"–3/4"); OAL ±.060
- MS1 tolerances: cutting dia. +.000/−.075mm; shank dia. −.002/−.005mm; flute length +0.500/+1.500mm; OAL ±10mm
- Available with wiper flats (guide p.17), coolant grooves (guide p.16), and 45° chamfer (guide p.17)
- S1-301/S1-401 available with shank flats to eliminate slippage in the tool holder (guide p.18)
From the RobbJack Applications Guide.



About this series
S1 C-2 Grade Carbide Stub Length End Mills
Stub-length C-2 carbide end mills in 2, 3, and 4 flute.
The S1 series is an inch-sized line of stub length C-2 grade solid carbide end mills offered in 2-flute (S1-201), 3-flute (S1-301), and 4-flute (S1-401) styles with a 30-degree helix and square end. Cutting diameters range from 1/16 inch up to 3/4 inch. Available with wiper flats, coolant grooves, and a 45-degree chamfer option; flats are available to eliminate slippage in the tool holder.
- C-2 grade carbide
- Stub length
- 30-degree helix
- Square end
- 2, 3, and 4 flute versions
- Available with wiper flats
- Available with coolant grooves
- Available with 45-degree chamfer
Aluminum, Copper, Magnesium, Plastics, Composites, Brass. Diamond-Like Carbon (DLC) coating available; dry, wet, cold air, or spray mist.
Headline spec
Cutting diameters 1/16 inch to 3/4 inch; C-2 grade carbide, stub length.
Best for
- Slotting
- Side Milling
- Helical Interpolation
- High Performance machining
- Roughing
- Semi-Finishing
- Finishing
Specifications
US machining terms with ISO 13399 codes.
- Cutting DiameterDC
- 0.5″
- Diameter ToleranceDC tol
- 0.0000/-0.0020
- Max Cutting DiameterDCX
- 0.5″
- Shank DiameterDMM
- 0.5″
- Length of Cut (LOC)APMX
- 0.625″
- Overall Length (OAL)OAL
- 3″
- 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
- S1-301 — 3 Flute Stub Length C-2 Grade Carbide End Mill
Cuts these materials
Applications
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| Cutting Diameter | 0 | -0.003 |
| Length of Cut | +0.06 | 0 |
| Overall Length | +0.06 | -0.06 |
| Shank Diameter | -0.0001 | -0.0002 |
Choose the finish(2 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 S1-301-16
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
$139.40
S1-301-16
Starting speeds & feeds for the S1-301-16
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) |
|---|---|---|---|---|---|---|---|
| 6061(T4-T6) Aluminum | Roughing — full slot | 1,572 | 12,000 | 400 | .01111 | .4800 | .5000 |
| 6061(T4-T6) Aluminum | Finishing | 1,572 | 12,000 | 230.4 | .00640 | .5000 | .0250 |
| Free-Cutting Brass | Roughing — full slot | 750 | 5,730 | 110 | .00640 | .5000 | .5000 |
| Free-Cutting Brass | Finishing | 750 | 5,730 | 55 | .00320 | .5000 | .0250 |
| Acetal | Roughing — full slot | 1,572 | 12,000 | 400 | .01111 | .4800 | .5000 |
| Acetal | Finishing | 1,572 | 12,000 | 230.4 | .00640 | .5000 | .0250 |
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 S1-301 series
Same series, different size — what changes from this tool is shown in red.
- S1-301-02$28.50Ø 0.0625″LOC 0.125″OAL 1.5″3 FL
- S1-301-03$28.40Ø 0.0937″LOC 0.1875″OAL 1.5″3 FL
- S1-301-04$27.90Ø 0.125″LOC 0.25″OAL 1.5″3 FL
- S1-301-06$36.30Ø 0.1875″LOC 0.375″OAL 2″3 FL
- S1-301-08$36.30Ø 0.25″LOC 0.5″OAL 2″3 FL
- S1-301-10$57.50Ø 0.3125″LOC 0.5″OAL 2.5″3 FL
- S1-301-12$79.65Ø 0.375″OAL 2.5″3 FLLOC 0.625″
- S1-301-14$112.20Ø 0.4375″OAL 2.75″3 FLLOC 0.625″
- S1-201-02$28.50Ø 0.0625″2 FLLOC 0.125″OAL 1.5″
- S1-201-03$28.40Ø 0.0937″2 FLLOC 0.1875″OAL 1.5″
- S1-201-04$27.90Ø 0.125″2 FLLOC 0.25″OAL 1.5″
- S1-201-06$36.30Ø 0.1875″2 FLLOC 0.375″OAL 2″