A1-201-10
2 Flute Stub Length High Performance Carbide End Mill for Non-ferrous Material
0.3125-in Dia 2-Flute End Mill, 0.4687-in LOC, 0.3125-in Shank, 2.5-in OAL, 0.005-in Chamfer
OrderingA1-201-10·Uncoated·$81.85Change finish


2 and 3 flute high-performance aluminum end mills — the stub-length A1-201 cuts the horsepower a cut demands, and the polished Mirror Edge A1-303 is the chatter-killer a defense manufacturer called 'the only tool that could make the part.'
- Two geometries: A1-201 2-flute stub length (30° helix) designed to reduce required horsepower, and A1-303 3-flute standard length (35° helix) with Mirror Edge and polished flutes for chatter reduction
- Inch sizes 1/8"–1" cutting diameter; metric MA1 line runs 3–20 mm in both 201 and 303 geometries
- Corner break (chamfer) on every size — .005 on 1/8"–5/16", .010 on 3/8"–3/4", .015 on 1" (MA1: 0.1–0.3 mm)
- Guide-published speeds & feeds run at Max RPM in aluminum 6061/7075/2024 with chip loads scaling from .0032 (1/8") to .0160 (1") per tooth
- Axial depth of cut up to 1.5 × diameter with 50% radial step-over per the guide's A1 speeds & feeds pages
- Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, and finishing; A1-201 runs dry, wet, cold air, or spray mist (A1-303: wet)
- Materials: aluminum, copper, magnesium, brass — plus plastics on the 2-flute A1-201
- Available uncoated or Diamond-Like Carbon (DLC) coated on every size
- Guide case story: in deep-pocket/thin-wall aluminum at a major defense manufacturer, the A1-303 was the only tool that could make the part — 8 other high-performance tools tried and failed (6 broke, 2 loaded up with aluminum)
- h4 shank tolerance — up to 150% more gripping force to eliminate tool pull-out ('tightest in the industry'); A1 tolerances: cutting dia −.0007/−.0015, shank −.0001/−.0002, flute length +.060/−.000
From the RobbJack Applications Guide.

About this series
A1 High Performance Tools for Aluminum
Polished & Mirror Edge!
The A1 is RobbJack's high-performance carbide line for aluminum, offered as a 2-flute stub-length tool (A1-201) to reduce required horsepower and as a 3-flute standard-length tool (A1-303) for chatter reduction with a polished mirror edge. Tools feature a corner break/chamfer and are available uncoated or DLC coated.
- 2 flute stub length (A1-201) to reduce required horse-power
- 3 flute standard length (A1-303) for chatter reduction
- 30° helix (2 flute) / 35° helix (3 flute)
- Polished mirror edge (3 flute)
- Corner break / corner chamfer
- DLC (Diamond-Like Carbon) coating available
- Available with Wiper Flats and Coolant Grooves
Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, finishing (dry, wet, cold air, spray mist). A1-201 axial depth of cut up to 1 × tool diameter up to a full slot; A1-303 axial depth up to 1.5 × diameter with 50% radial step over.
Headline spec
Cutting dia. tolerance −.0007/−.0015, shank dia. −.0001/−.0002
Best for
- Aluminum (6061-T6, 7075, 2024)
- Copper
- Magnesium
- Brass
- Plastics
Specifications
US machining terms with ISO 13399 codes.
- Cutting DiameterDC
- 0.3125″
- Diameter ToleranceDC tol
- -0.0010/-0.0015
- Max Cutting DiameterDCX
- 0.3115″
- Shank DiameterDMM
- 0.3125″
- Length of Cut (LOC)APMX
- 0.4687″
- Overall Length (OAL)OAL
- 2.5″
- Corner ChamferCHW
- 0.005″
- Chamfer AngleKCH
- 45°
- Number of FlutesNOF
- 2
- Helix AngleFHA
- 30°
- Helix HandFHH
- Right-hand
- Cut Direction
- Right-hand cut
- End Type
- Chamfer
- Center Cutting
- Yes — plunges
- Series
- A1-201 — 2 Flute Stub Length High Performance Carbide End Mill for Non-ferrous Material
Cuts these materials
Applications
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| Cutting Diameter | -0.001 | -0.0015 |
| 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 A1-201-10
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
$81.85
A1-201-10
Starting speeds & feeds for the A1-201-10
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 | 983 | 12,000 | 192 | .00800 | .3125 | .3125 |
| 6061(T4-T6) Aluminum | Finishing | 983 | 12,000 | 96 | .00400 | .3125 | .0156 |
| Free-Cutting Brass | Roughing — full slot | 750 | 9,168 | 73.3 | .00400 | .3125 | .3125 |
| Free-Cutting Brass | Finishing | 750 | 9,168 | 36.7 | .00200 | .3125 | .0156 |
| Acetal | Roughing — full slot | 983 | 12,000 | 192 | .00800 | .3125 | .3125 |
| Acetal | Finishing | 983 | 12,000 | 96 | .00400 | .3125 | .0156 |
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 A1-201 series
Same series, different size — what changes from this tool is shown in red.
- A1-201-04$30.95Ø 0.125″LOC 0.1875″OAL 1.5″2 FL
- A1-201-06$46.95Ø 0.1875″LOC 0.2812″OAL 2″2 FL
- A1-201-08$55.15Ø 0.25″LOC 0.375″OAL 2″2 FL
- A1-201-12$99.20Ø 0.375″LOC 0.5625″2 FLOAL 2.5″
- A1-201-16$164.25Ø 0.5″LOC 0.75″OAL 3″2 FL
- A1-201-20$298.85Ø 0.625″LOC 0.9375″OAL 3.5″2 FL
- A1-201-24$452.75Ø 0.75″LOC 1.125″OAL 4″2 FL
- A1-201-32$691.30Ø 1″LOC 1.5″OAL 4″2 FL
- A1-303-04$35.80Ø 0.125″3 FLLOC 0.375″OAL 1.5″
- A1-303-06$53.65Ø 0.1875″3 FLLOC 0.5625″OAL 2″
- A1-303-08$81.05Ø 0.25″3 FLLOC 0.75″OAL 2.5″
- A1-303-10$81.553 FLLOC 0.875″Ø 0.3125″OAL 2.5″