CR-402-08
4 Flute Compression Composite Router
0.25-in Dia 4-Flute End Mill, 0.75-in LOC, 0.25-in Shank, 2.5-in OAL
OrderingCR-402-08·Uncoated·$121.45Change finish
Compression router geometry — clean edges on both faces of the laminate, 10-20X tool life.
- Compression geometry: up-shear flutes at the tip transition to down-shear flutes above, pressing both skins of the laminate inward so neither face frays or delaminates
- 4 flute on 1/4" diameter (CR-402-08), 6 flute on 3/8" and 1/2" diameters (CR-602-12, CR-602-16)
- Dedicated up-shear length per size: 3/16" on 1/4" dia, 1/4" on 3/8" and 1/2" dia
- Three finishes: uncoated, Black Widow DLC coated (-DLC), and Diamond Coated DCC (-D)
- Metric MCR line in 6mm (4 flute), 10mm and 12mm (6 flute) with 5-6mm upshear lengths
- 10-20X tool life with diamond coating
- Tolerances: cutting dia -.001/-.003, shank dia -.0001/-.0002, OAL +/-.060
- Runs dry, wet, cold air, or spray mist; slotting, side milling, helical interpolation, ramping through finishing
From the RobbJack Applications Guide.
About this series
CR / MCR Compression Routers
4- and 6-flute compression routing for composites.
The CR Series is a 4- and 6-flute compression router (square end) for composites, with an up-shear/down-shear geometry. Available uncoated, Black Widow DLC coated, and diamond coated; metric MCR versions are also offered.
- 4- and 6-flute compression (up/down shear) geometry
- Available uncoated, Black Widow Diamond-Like Carbon (DLC) coated, and Diamond Coated (DCC)
- Inch (CR) and metric (MCR) sizes
Composites. Dry, Wet, Cold Air, or Spray Mist. Applications: slotting, side milling, helical interpolation, ramping, roughing, semi-finishing, finishing.
Headline spec
10-20X tool life
Best for
- Routing composite panels without top/bottom delamination
Specifications
US machining terms with ISO 13399 codes.
- Cutting DiameterDC
- 0.25″
- Diameter ToleranceDC tol
- -0.0010/-0.0030
- Max Cutting DiameterDCX
- 0.249″
- Shank DiameterDMM
- 0.25″
- Length of Cut (LOC)APMX
- 0.75″
- Overall Length (OAL)OAL
- 2.5″
- Number of FlutesNOF
- 4
- Helix HandFHH
- Right-hand
- Cut Direction
- Right-hand cut
- End Type
- Square End
- Center Cutting
- Yes — plunges
- Shear Direction
- Compression (up + down)
- Series
- CR-402 — 4 Flute Compression Composite Router
Cuts these materials
Applications
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| Cutting Diameter | -0.001 | -0.003 |
| Length of Cut | +0.02 | +0.03 |
| Overall Length | +0.06 | -0.06 |
| Shank Diameter | -0.0001 | -0.0002 |
Choose the finish(3 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 CR-402-08
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
$121.45
CR-402-08
Starting speeds & feeds for the CR-402-08
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) |
|---|---|---|---|---|---|---|---|
| Carbon Fiber CFRP | Roughing — full slot | 786 | 12,000 | 96 | .00200 | .2500 | .2500 |
| Carbon Fiber CFRP | Finishing | 786 | 12,000 | 48 | .00100 | .2500 | .0125 |
| Lab Top (Laminate) | Roughing — full slot | 750 | 11,460 | 91.7 | .00200 | .2500 | .2500 |
| Lab Top (Laminate) | Finishing | 750 | 11,460 | 45.8 | .00100 | .2500 | .0125 |
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 CR-402 series
Same series, different size — what changes from this tool is shown in red.