4-Flute Stub-Length Solid Carbide Internal-Radius End Mill for Steel

Это 4-flute stub-length solid carbide internal-radius end mill is designed for precision radius profiling, mold details and smooth curved transitions in steel machining. Its compact tool length helps improve rigidity and machining stability, while the 4-flute cutting geometry supports consistent radius formation and smooth profile finishing on CNC machining centers.

  • ◆Form-ground internal-radius profile for consistent corner and transition geometry
  • ◆Stub-length design provides a compact, rigid setup for precision CNC milling
  • ◆4-flute geometry supports stable cutting engagement and smooth profile finishing
  • ◆Standard R1–R6 sizes with custom radius, shank, length and coating options available

Product Configurations
Workpiece Materials: Carbon steel, alloy steel, mold steel
Standard Radius Options: R1 / R1.5 / R2 / R2.5 / R3 / R4 / R5 / R6
Варианты покрытия: AlTiN / TiAlN / TiSiN / AlTiSiN / TiN
Helix Options: 30° / 35° / 45° — availability confirmed according to the selected radius and tool specification

Consistent Quality

Consistent geometry across repeat orders.

Гибкие заказы

Small batches and mixed sizes available.

OEM Support

Custom marking, labels and packaging.

Стандартные и индивидуальные

Standard sizes and custom configurations.

Carbide Internal-Radius End Mill Overview

This 4-flute stub-length solid carbide internal-radius end mill is designed for precision radius machining, mold details and smooth curved transitions in steel components. The formed radius profile allows defined internal-radius features to be machined with consistent geometry, while the compact tool length provides a rigid setup for CNC milling. Four cutting edges support stable engagement during profile machining and finishing, and the micro-grain solid carbide substrate provides the strength and dimensional stability required for steel-oriented applications. Standard 4-flute configurations cover radius sizes from R1 to R6 mm.

Радиус действия
R1–R6 mm
Флейта
4 флейты
Tool Material
Micro-Grain Carbide
Standard OAL
50 / 60 / 75 mm

Internal-Radius Cutting Configuration

Form-Ground Radius Profile

The cutting profile is ground to the specified radius for machining defined internal-radius features, mold details and smooth transitions between adjacent surfaces.

Stub-Length Rigid Design

Compact 50–75 mm standard overall lengths help maintain tool rigidity and reduce unnecessary overhang during precision radius machining.

4-Flute Cutting Geometry

Four cutting edges provide repeated cutting engagement for stable profile machining and consistent surface finishing in steel applications.

Application-Specific Advantages

R

Defined Radius Geometry

Standard R1–R6 configurations cover common internal-radius and transition requirements.

4F

Four Cutting Edges

The 4-flute layout supports stable cutting engagement during radius profiling and finishing.

ST

Compact Tool Length

Stub-length configurations provide a compact cutting setup where extended reach is not required.

OEM

Custom Radius Options

Radius, shank diameter, overall length, coating and profile geometry can be reviewed for non-standard orders.

Recommended Machining Operations

Internal Radius Machining
RECOMMENDED
Curved Transitions
RECOMMENDED
Mold Detail Profiling
RECOMMENDED
Profile Finishing
SUITABLE

Application Note:
Match the cutter radius to the required component radius and confirm adequate tool clearance around adjacent walls and features. Use a low-runout holder and the shortest practical overhang for precision radius finishing.

Workpiece Material Compatibility

MATERIAL GROUP APPLICATION LEVEL
P Carbon Steel Radius profiling, mold details and curved transitions Primary
P Alloy / Mold Steel Coating selected according to steel grade and hardness Primary
M Stainless Steel Application-specific coating and machining parameters recommended Application Review
K Cast Iron Suitable configuration selected according to workpiece condition Suitable

Product Details

Product views showing the internal-radius cutting profile, 4-flute geometry and compact solid carbide tool construction.

4 flute solid carbide internal radius end mill for steel
stub length internal radius carbide end mill
solid carbide internal R milling cutter
internal radius end mill cutting geometry
4 flute internal radius end mill standard sizesinner R carbide end mill main photo internal R carbide end mill carbide inner R end mill for steel4-Flute Stub-Length Solid Carbide Internal-Radius End Mill for Steel 1 4-Flute Stub-Length Solid Carbide Internal-Radius End Mill for Steel 3 4-Flute Stub-Length Solid Carbide Internal-Radius End Mill for Steel 5

Tool Nomenclature & Dimensions

Reference dimensions for the 4-flute stub-length solid carbide internal-radius end mill. Select the radius according to the required component profile, then confirm shank diameter and overall length according to machining access and holder requirements. All listed dimensions are in millimeters.

solid carbide internal radius end mill dimension drawing
R: Радиус дуги d: Диаметр хвостовика L: Общая длина T: Cutting Edge Count
Radius Note: Select the cutter radius according to the required finished component radius. Confirm adjacent-wall clearance and the complete profile geometry when replacing an existing form cutter.

Technical Configuration

PARAMETER REFERENCE CONFIGURATION
Тип инструмента Internal-Radius End Mill / Inner-R Form Cutter
Tool Material Микрозернистый карбид вольфрама
Флейта 4 флейты
Standard Radius Range R1 / R1.5 / R2 / R2.5 / R3 / R4 / R5 / R6 mm
Shank Diameter Range Ø4–Ø14 mm for listed 4-flute standard sizes
Общая длина 50 / 60 / 75 mm standard 4-flute configurations
Варианты покрытий AlTiN / TiAlN / TiSiN / AlTiSiN / TiN / application-specific options
Reference Tolerance 0 ~ ±0.01 mm reference; final tolerance confirmed according to feature and specification
Primary Materials Carbon Steel / Alloy Steel / Mold Steel / Tool Steel
Совместимость с машинами CNC Machining Centers / Milling Machines
Настройка Radius, shank diameter, overall length, cutting profile, coating and marking can be reviewed according to drawings and application requirements.

Standard 4-Flute Size Matrix

Reference 4-flute configurations for the stub-length internal-radius end mill series.

SPECIFICATION ARC RADIUS R SHANK DIA. d OVERALL LENGTH L FLUTES
R1 × 4 × 50 × 4T 1 4 50 4
R1.5 × 6 × 50 × 4T 1.5 6 50 4
R2 × 6 × 50 × 4T 2 6 50 4
R2.5 × 8 × 50 × 4T 2.5 8 50 4
R3 × 8 × 50 × 4T 3 8 50 4
R4 × 10 × 60 × 4T 4 10 60 4
R5 × 12 × 75 × 4T 5 12 75 4
R6 × 14 × 75 × 4T 6 14 75 4
Size Note: The listed dimensions are standard 4-flute references. Non-standard radii, shank diameters and overall lengths can be reviewed according to the workpiece drawing and machining requirements.

Internal-Radius Milling Application Guidance

  • Radius Selection: Match the cutter radius directly to the required component radius or existing tool specification.
  • Profile Clearance: Check adjacent walls, shoulders and surrounding geometry to ensure the formed cutter can reach the radius without interference.
  • Toolholding: Use a clean, low-runout precision holder for consistent radius geometry and surface quality.
  • Tool Overhang: Use the shortest practical overhang to take advantage of the stub-length tool configuration.
  • Coating Selection: Select the coating according to steel grade, hardness and machining conditions.

4-Flute Internal-Radius End Mill Customization

Arc radius, cutting profile, shank diameter, overall length, cutting-edge preparation and coating can be configured for internal-radius machining, mold details, curved transitions and profile finishing in steel components. Standard 4-flute stub-length configurations cover R1–R6 mm radius sizes with Ø4–Ø14 mm shank diameters and 50–75 mm overall lengths. Non-standard radius profiles and dimensions can be reviewed according to the component drawing, adjacent-wall clearance, workpiece material, machining depth, holder configuration and required profile accuracy.

PARAMETER MANUFACTURING CAPABILITIES
Радиус дуги Standard 4-flute radius configurations include R1, R1.5, R2, R2.5, R3, R4, R5 and R6 mm. Non-standard radii can be reviewed according to the finished component profile or existing cutter sample.
Internal-R Profile The formed cutting profile can be matched to the required internal radius, curved transition or mold feature. Critical profile geometry should be confirmed from the component drawing for non-standard applications.
4-Flute Configuration The standard configuration uses four cutting edges for repeated engagement during radius profiling and finishing. Final edge geometry can be reviewed according to workpiece material, cutting engagement and surface-finish requirements.
Stub-Length Design Standard overall lengths of 50, 60 and 75 mm provide a compact tool configuration where additional reach is not required. Shorter tool projection helps maintain a rigid machining setup.
Диаметр хвостовика Standard 4-flute configurations use Ø4, Ø6, Ø8, Ø10, Ø12 and Ø14 mm shank diameters according to radius size. Non-standard shank dimensions can be reviewed for holder compatibility.
Общая длина Reference overall lengths are 50, 60 and 75 mm for the standard 4-flute series. Drawing-defined lengths can be reviewed where different holder clearance or machining access is required.
Profile Clearance Tool body and profile dimensions can be reviewed according to adjacent walls, shoulders and surrounding features to provide adequate access to the required internal radius.
Cutting-Edge Preparation Rake geometry, relief, edge preparation and flute finishing can be reviewed according to the steel grade, hardness, cutting load and required radius-surface quality.
Coating Selection AlTiN, TiAlN, TiSiN, AlTiSiN, TiN and other application-specific coatings can be reviewed according to steel grade, hardness, cutting conditions and required tool life.
Материал заготовки The product is positioned mainly for carbon steel, alloy steel, mold steel and tool-steel applications. Stainless-steel and other materials can be reviewed with the appropriate geometry and coating.
Machining Application Geometry can be reviewed for internal-radius machining, curved-surface transitions, mold-detail profiling and profile finishing on CNC machining centers and milling machines.
Dimensional Requirements Drawing-defined requirements can be reviewed for arc radius, profile geometry, shank diameter, overall length, feature clearance, profile accuracy and tool runout.
Replacement Tool Matching Existing cutter dimensions and profile geometry can be reviewed from a tool drawing or physical sample for replacement and equivalent-tool requirements.
OEM & Private Label Laser marking, custom tool codes, private labels and packaging can be reviewed for distributors and OEM customers according to specification and order quantity.
Примечание инженера: Please provide the workpiece material and hardness, required arc radius R, shank diameter d, overall length L, internal-radius or transition profile, machining depth, adjacent-wall clearance, coating preference, holder information and order quantity. A component drawing, existing tool drawing or physical sample is strongly recommended for replacement and non-standard radius tools. Final profile geometry, coating and custom dimensions are confirmed after technical review.

Услуги по производству под брендом OEM и под частной торговой маркой

OEM manufacturing and private-label supply options are available for industrial distributors, tooling brands and repeat-production customers. Laser identification, label content, protective packaging and coating presentation can be configured according to the approved product specification and order requirements.

OEM laser marking custom labels coatings and packaging for solid carbide square end mills

Laser Etching

Custom logos, tool codes, cutting dimensions, coating identification and batch numbers can be marked according to the available shank area.

Custom Labels & Packaging

Individual protective tubes, product labels, specification details, colored packaging tubes and private-label packaging can be reviewed.

Commercial Terms

MOQ, sample evaluation, custom-size trials, repeat orders and scheduled supply programs are confirmed according to the selected configuration.

Technical Workflow

A structured review process is used to confirm standard, customized and private-label square end mill requirements before production.

STAGE 01

Inquiry

Submit the material, hardness, milling operation, dimensions, tolerance and quantity.

STAGE 02

Engineering

Review flute geometry, helix angle, edge preparation, coating, ap and ae.

STAGE 03

Commercial

Confirm quotation, MOQ, sample requirements, production schedule and delivery terms.

STAGE 04

Production

CNC grinding, end-face formation, edge preparation, coating and laser marking.

STAGE 05

Quality Control

Inspect diameter, flute length, shank, runout, square-end geometry and cutting edges.

Quality, Inspection & Delivery

Our solid carbide square end mills are controlled through material verification, precision grinding, in-process measurement and final inspection. Key dimensions, square-end geometry, cutting-edge condition, coating appearance and product identification are reviewed according to the approved specification or drawing before packing.

Controlled manufacturing and final inspection for solid carbide square end mills

Three-Stage Quality Control

Inspection checkpoints are arranged around the manufacturing process to support dimensional consistency and repeat-order control.

STAGE 01

Incoming Material Control

Carbide substrate grade, blank dimensions and supplied material information are checked against the production requirement.

STAGE 02

In-Process Grinding Control

Cutting diameter, flute geometry, flute length, square-end profile and shank dimensions are monitored during CNC grinding.

STAGE 03

Final Tool Inspection

Finished tools are reviewed for specified dimensions, runout, cutting-edge condition, coating appearance, marking and packing identification.

Key Inspection Characteristics

Inspection requirements are confirmed according to the standard product specification or the approved custom drawing.

INSPECTION ITEM CONTROL FOCUS CONFIRMATION BASIS
Cutting Diameter (DC) Diameter and dimensional consistency Standard specification or approved drawing
Flute Length (APMX) Effective cutting length Confirmed product size or drawing requirement
Shank Diameter (DCON) Clamping-section dimension and surface condition Applicable shank specification
Общая длина (OAL) Total tool length Standard size matrix or approved drawing
Радиальное биение Concentricity between cutting section and shank Agreed inspection requirement
Square-End Geometry End-face profile, corner condition and center-cutting form Selected tool configuration
Flute & Helix Profile Flute count, helix form and grinding consistency Approved manufacturing configuration
Cutting Edge & Coating Edge condition, visible defects and coating appearance Application-specific production requirement
Marking & Identification Tool code, dimensions and batch information where applicable Confirmed order and packaging specification

Measurement & Batch Traceability

Optical measuring systems, tool inspection equipment and appropriate dimensional gauges are selected according to the feature being checked.

Optical Measurement

Profile and dimensional review of specified cutting features.

Runout Verification

Concentricity review based on the agreed product requirement.

Edge Inspection

Magnified review of the end face, corners and cutting-edge condition.

Batch Identification

Order, product and batch information are linked where required for repeat supply.

Inspection Documentation: Dimensional records, sample inspection requirements or additional documentation can be reviewed according to the order specification before production.

Protective Packaging Process

Finished end mills are protected to reduce contact between cutting edges and to support clear product identification during storage and transportation.

Protective packaging process for solid carbide end mills
01 Individual ProtectionProtective tubes or cases help shield cutting edges.
02 Batch IdentificationLabels identify the applicable tool and order information.
03 Carton ProtectionInternal cushioning is selected according to the shipment.
04 Ready for DispatchCartons are closed and prepared for the confirmed shipping method.

Bulk-Order & Export Packaging

Bulk shipments can be arranged with reinforced cartons, protective wrapping, palletized loading or export cases according to order quantity, shipment weight and agreed transportation requirements.

Bulk-order and export packaging for HY Cutting Tools shipments

Delivery Coordination

Production completion, packing method and dispatch arrangements are confirmed according to the approved order. Courier, air, sea or customer-designated shipping options can be reviewed according to shipment size and destination. Final lead time is confirmed after product specifications, quantity and packaging requirements are approved.

Product & Application FAQs

Common questions about selecting and applying the 4-Flute Stub-Length Solid Carbide Internal-Radius End Mill for steel radius machining, mold details and curved-profile finishing.

What is this internal-radius end mill designed for?
It is designed for machining defined internal-radius profiles, mold details and smooth transitions between adjoining surfaces. The formed cutting profile should be matched to the radius specified on the component drawing.
How should I select the correct radius?
Select the cutter according to the finished radius required on the component. Standard 4-flute configurations range from R1 to R6 mm. For replacement tools or non-standard profiles, a component drawing or existing tool sample is recommended.
What is the benefit of the stub-length design?
The compact overall length reduces unnecessary tool overhang when additional reach is not required. This provides a more rigid setup for precision radius machining and profile finishing.
What is the advantage of the 4-flute configuration?
The 4-flute configuration provides four cutting edges for repeated engagement during profile machining. It is suited to stable radius finishing where sufficient chip clearance is available for the selected material and cutting conditions.
Which steel materials can this cutter machine?
The product is positioned mainly for carbon steel, alloy steel, mold steel and tool-steel applications. Stainless steel and other materials can be reviewed with the appropriate coating and machining conditions.
Which coatings are available?
Available coating options include AlTiN, TiAlN, TiSiN, AlTiSiN, TiN and application-specific configurations. Final coating selection should be based on steel grade, hardness, machining conditions and required tool life.

Ordering & Customization FAQs

Ordering information for distributors, tooling suppliers and OEM customers requiring standard or customized internal-radius end mills.

What standard 4-flute sizes are available?
Reference 4-flute configurations cover R1, R1.5, R2, R2.5, R3, R4, R5 and R6 mm, with Ø4–Ø14 mm shank diameters and 50–75 mm overall lengths.
Are 2-flute internal-radius cutters also available?
Yes. Related 2-flute configurations are available in the internal-radius cutter series. This page focuses on the 4-flute stub-length version for steel machining.
Can a non-standard radius be customized?
Yes. Non-standard radius profiles, shank diameters, overall lengths, coating and related geometry can be reviewed according to a component drawing, existing tool drawing or physical sample.
Are OEM marking and private-label packaging available?
Yes. Laser marking, custom tool codes, private labels and packaging can be reviewed according to order quantity and available marking space.
Каковы обычные сроки выполнения заказа?
When available from stock, standard specifications are generally ready for shipment within 1–3 working days. Lead time for customized radius profiles or dimensions is confirmed after specification and quantity review.
What information should I provide for quotation?
Please provide the workpiece material and hardness, required radius R, shank diameter d, overall length L, machining feature, available tool clearance, coating preference and order quantity. A component drawing or existing cutter sample is recommended for non-standard profiles.

Technical Downloads

Reference documents for solid carbide cutter selection and starting machining-data review.

Solid Carbide End Mill Catalog

Review internal-radius cutters and related solid carbide milling tool series.

View Catalog

End Mill Speeds & Feeds Guide

Access reference starting parameters for machining trials and application review.

View Guide

Need Sizes, Pricing or Custom Options?

Send us the required tool type, sizes, quantities, workpiece material and any OEM or custom requirements. We will confirm suitable specifications, availability, lead time and quotation details.

Standard Sizes Small Trial Orders Mixed Sizes OEM & Custom Options
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Drawings, size lists and reference photos are welcome.