MST-430-20
4 Flute Standard Length Metric Super Tuffy Grade Carbide End Mill
20mm Dia 4-Flute Metric End Mill 38mm LOC, 20mm Shank, 104mm OAL


Super Tuffy grade carbide end mills for steel and high-temp alloys -- 3, 4, and 6 flute geometries with T-Process honed edges, corner breaks, and helix angles from 30 to 60 degrees, in inch (ST) and metric (MST).
- Super Tuffy carbide grade built for cast iron, steel, stainless steel, and super alloys
- ST-341 (3 flute stub) and ST-343 (3 flute standard): 40-degree helix with corner break and T-Process hone, rated high performance from slotting and ramping through finishing, 1/8" to 3/4"
- ST-360 (3 flute standard): 60-degree high-helix finisher for side milling, 1/8" to 3/4"
- ST-430 (4 flute standard, sharp edges) and ST-434 (4 flute standard, corner break with T-Process hone): 30-degree helix for side milling from roughing through finishing, 1/8" to 3/4" including half sizes on ST-430
- ST-630 (6 flute square end, 30-degree helix) and ST-646 (6 flute corner radius, 40-degree helix, honed radius): 3/8" to 1"; ST-646 available with coolant grooves (see guide page 13)
- Corner break sizes scale with diameter, from .003/.005 at 1/8" up to .011/.014 at 3/4"; ST-646 corner radii run .005/.007 to .012/.015
- Metric MST line mirrors the geometry: MST-341, MST-360, MST-430, MST-434 from 3 mm to 20 mm, and MST-646 from 10 mm to 20 mm
- Available uncoated or in TiN, TiCN, and AlTiN coatings
- Inch tolerances (ST-341/343): cutting diameter +.000/-.002 (1/8" to 1/4") or +.000/-.003 (5/16" to 3/4"), shank -.0001/-.0002, OAL +/-.060; ST-630/646 cutting diameter +.001/-.000; metric MST cutting diameter +.000/-.075 mm
- Need reach? See End Mill Modifications, guide page 14
From the RobbJack Applications Guide.
About this series
MST Metric Super Tuffy Grade Carbide End Mills
Metric honed-edge Super Tuffy tools for steel & high-temp alloys
MST is the metric variant of the ST Series: Super Tuffy Grade carbide end mills with T-Process honed edge in 3, 4 and 6 flute geometries (MST-341, MST-360, MST-430, MST-434, MST-646), available uncoated or TiN, TiCN, AlTiN coated, in 3-20 mm sizes.
- 3, 4 and 6 flute configurations
- Square end and corner-radius / corner-break options
- T-Process honed edge
- Available uncoated or TiN, TiCN, AlTiN coated
- Metric sizes 3 mm to 20 mm
Cast iron, steel, stainless steel and super alloys. Slotting, side milling, ramping, roughing and finishing.
Headline spec
Metric Super Tuffy Grade carbide with T-Process honed edge
Best for
- Metric steel and stainless machining
- Super alloys
- Roughing through finishing
Specifications
US machining terms with ISO 13399 codes.
- Cutting DiameterDC
- 20 mm
- Diameter ToleranceDC tol
- 0.025/0.000
- Shank DiameterDMM
- 20 mm
- Length of Cut (LOC)APMX
- 38 mm
- Overall Length (OAL)OAL
- 104 mm
- Number of FlutesNOF
- 4
- Helix AngleFHA
- 30°
- Helix HandFHH
- Right-hand
- Cut Direction
- Right-hand cut
- End Type
- Square End
- Center Cutting
- Yes — plunges
- Series
- MST-430 — 4 Flute Standard Length Metric Super Tuffy Grade Carbide End Mill
Cuts these materials
Applications
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| Cutting Diameter | +0.025 | 0 |
| Length of Cut | +0.5 | +1.5 |
| Overall Length | +1 | -1 |
| Shank Diameter | -0.002 | -0.005 |
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 Aluminum Titanium Nitride (AlTiN) · $460.10 — our pick for your material. Choose another finish below.
Proven in the field
- $548,290saved per year drilling carbon-fiber aircraft
- $216,000saved per year trimming aircraft skins
- 1,000%metal-removal increase in Inconel 718 (SPS)
Finishes (4)
Uncoated
MST-430-20
$442.20
Available to order
MST-430-20-A
$460.10
Available to order
MST-430-20-C
$458.15
Available to order
MST-430-20-T
$454.05
Available to order
Starting at
$442.20
Performance guaranteed
More in the MST-430 series
Same series, different size — what changes from this tool is shown in red.
- MST-430-03$37.95Ø 3 mmLOC 12 mmOAL 38 mm4 FL
- MST-430-04$44.30Ø 4 mmLOC 12 mmOAL 50 mm4 FL
- MST-430-05$60.25Ø 5 mmLOC 14 mmOAL 50 mm4 FL
- MST-430-06$58.30Ø 6 mmLOC 14 mmOAL 57 mm4 FL
- MST-430-08$108.70Ø 8 mmLOC 16 mmOAL 63 mm4 FL
- MST-430-10$116.45Ø 10 mmLOC 20 mmOAL 72 mm4 FL
- MST-430-12$179.75Ø 12 mmLOC 25 mmOAL 83 mm4 FL
- MST-430-16$290.20Ø 16 mmLOC 32 mmOAL 92 mm4 FL
- MST-341-03$35.25Ø 3 mm3 FLLOC 6 mmOAL 38 mm
- MST-341-04$60.20Ø 4 mm3 FLLOC 8 mmOAL 50 mm
- MST-341-05$75.80Ø 5 mm3 FLLOC 8 mmOAL 50 mm
- MST-341-06$55.55Ø 6 mm3 FLLOC 8 mmOAL 57 mm