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End MillRouterMade in USA

AL3-304-32-BN

3 Flute Aluminum Chatter Reduction Hi-Performance Long Len. Carbide End Mill

1-in Dia 3-Flute End Mill, 4-in LOC, 1-in Shank, 7-in OAL, 0.5 CR, with Chip Breakers

3 Flute Aluminum Chatter Reduction Hi-Performance Long Len. Carbide End Mill — AL3-304-32-BN
Series photo — representative of the AL3-304 family
OAL 7″Flute 4″Shank Ø1″Cutter Ø1″Ball
Scaled drawing — true to this tool's dimensions (inch)
Speeds & FeedsDialed to this exact tool — free
RobbJack AL3 3-flute high-performance aluminum carbide end mill with long flute length and polished flutes

Next-generation 3-flute aluminum end mills with Mirror Edge chatter reduction — standard, long, and extra-long lengths to 5" of flute, with corner radii, ball ends, thru-coolant, and chip breakers on the long tools.

  • 3 flute, 35° helix, with Mirror Edge and polished flutes — the guide's 'NEXT GENERATION' chatter-and-vibration eliminator for aluminum
  • Three lengths per diameter: AL3-303 standard, AL3-304 long, AL3-305 extra-long — up to 5" flute length on an 8" OAL at 1" diameter
  • Inch sizes 1/8"–1"; corner options from sharp corner through radii of .01", .03", .06", .09", .12", .19", and .25" (by diameter) plus ball-end (-BN) versions
  • All AL3-304 (long) and AL3-305 (extra-long) tools come standard with chip breakers to control chips
  • Four ways to buy every geometry: uncoated, DLC coated, thru-coolant uncoated (-TC), and thru-coolant DLC (-TC-DLC); on 1/8" and 3/16" diameters the thru-coolant version is a non-center-cutting single thru hole
  • Guide depth-of-cut guidance by length: AL3-303 at 50% radial width and 2–3 × diameter axial depth; AL3-304 at 30% radial and 4 × diameter at 70% CLPT; AL3-305 at 10% radial and 5 × diameter at 70% CLPT
  • Spring passes with long and extra-long tools may be needed to improve finish and deflection — RobbJack tested up to 4 spring passes with AL3-305 using the entire cutting length
  • Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, and finishing — wet; materials: aluminum, copper, magnesium, brass
  • h4 shank tolerance for up to 150% more gripping force; series tolerances: cutting dia −.0007/−.0015, shank −.0001/−.0002, flute length +.060/−.000, OAL ±.060
  • Due to the large offering, many AL3 items are made to order and non-returnable (per the guide)

From the RobbJack Applications Guide.

Engage the flutes, not just the tip
Engage the flutes, not just the tipStraight from the guide's AL3 profiling guidance: don't just use the tip of longer-length tools — engage most of the cutting edge (green check) instead of tip-only cuts (red X). RobbJack tested up to 4 spring passes with the AL3-305 using the entire cutting length.
Mirror Edge under magnification
Mirror Edge under magnificationThe polished, honed cutting edge of RobbJack's patented Mirror Edge treatment — the smooth edge dampens vibration to help eliminate chatter in thin walls and deep pockets.
A standard ground edge
A standard ground edgeFor comparison: a conventionally ground edge under the same magnification, with visible grinding striations — the serrated micro-edge that Mirror Edge polishing removes.

About this series

AL3 3 Flute High Performance Aluminum Carbide End Mill

Aluminum Machining Without Chatter!

The AL3 is RobbJack's 3-flute high-performance aluminum carbide end mill, engineered for chatter reduction with a polished, mirror-edge finish. It is available in Standard, Long, and Extra-Long lengths, square end, corner radius, and ball end, in uncoated, DLC-coated, thru-coolant, and thru-coolant DLC-coated configurations.

  • 3 flute
  • 35° helix
  • Polished mirror edge
  • Eliminates chatter and vibration
  • Thru coolant holes available
  • DLC (Diamond-Like Carbon) coating available
  • Long (AL3-304) and Extra-Long (AL3-305) lengths come standard with chip breakers to control chips
  • Standard, Long, and Extra-Long lengths with radii

Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, finishing, profiling (wet). Tested up to 4 spring passes without problems on AL3-305 using the entire cutting length.

Headline spec

h4 shank tolerance for up to 150% more gripping force — tightest in the industry

Best for

  • Aluminum (incl. 6061-T6, 6061-T3, 7075, 2024)
  • Copper
  • Magnesium
  • Brass

Specifications

US machining terms with ISO 13399 codes.

Cutting DiameterDC
1″
Diameter ToleranceDC tol
-0.0010/-0.0015
Max Cutting DiameterDCX
0.999″
Shank DiameterDMM
1″
Length of Cut (LOC)APMX
4″
Overall Length (OAL)OAL
7″
Corner RadiusRE
0.5″
Number of FlutesNOF
3
Helix AngleFHA
35°
Helix HandFHH
Right-hand
Cut Direction
Right-hand cut
End Type
Ball End
Center Cutting
Yes — plunges
Series
AL3-304 — 3 Flute Aluminum Chatter Reduction Hi-Performance Long Len. Carbide End Mill

Cuts these materials

AluminumCopper & BrassMagnesium

Applications

SlottingSide MillingHelical InterpolationRampingHigh PerformanceRoughingSemi-FinishingFinishingWet

Features

Mirror EdgePolished

See it run

Tolerances

TypeMinMax
Cutting Diameter-0.001-0.0015
Length of Cut+0.060
Overall Length+0.06-0.06
Shank Diameter-0.0001-0.0002
Starting at$872.75

Made & shipped in the USA · lead time confirmed at order. Buy at retail or through your distributor.

Performance guaranteed. Run it against the tool you use today — if it doesn't beat it, we'll make it right.

Adds Diamond-Like Carbon (DLC) · $945.35 — our pick for your material. Choose another finish below.

Calculate Speeds & FeedsDownload ISO 13399 data (.csv)

Finishes (2)

  • Uncoated

    AL3-304-32-BN

    $872.75

    Available to order

  • AL3-304-32-BN-DLC

    $945.35

    Available to order

Compare tool coatings →

Starting at

$872.75

Performance guaranteed

More in the AL3-304 series

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