MXR Series Solid Carbide Micro Back Turning Bars for Small Bore Internal Machining

Solid carbide MXR micro back turning bars for machining rear faces, internal undercuts and recessed features behind shoulders in small-diameter bores. Standard models cover cutting diameters from Ø2.8 to Ø5.9 mm, with custom dimensions, application-specific coatings, OEM marking and private-label support.
Sustrato:Fine-Grain Solid Carbide
Tipo de herramienta:Micro Back Turning Bar
Series:MXR
Cutting Width:1.3 / 1.5 mm
Cutting Diameter:Ø2.8–Ø5.9 mm
Shank Diameter:Ø4 / Ø5 / Ø6 mm
Clearance Length:10 / 15 / 22 mm
Custom Options:Dimensions / Back-Turning Geometry / Coating / Marking
Standard Dispatch1–3 Working Days
OEM y herramientas personalizadasDrawings / Samples
Minimum OrderMOQ 10 Pieces

Calidad constante

Consistent geometry across repeat orders.

Pedidos flexibles

Small batches and mixed sizes available.

OEM Support

Custom marking, labels and packaging.

Herramientas estándar y personalizadas

Standard sizes and custom configurations.

MXR Micro Back Turning Bar Overview

The MXR Series is a precision-ground solid carbide micro back turning bar designed for machining rear faces, internal undercuts and recessed features behind shoulders in small-diameter bores. The tool enters through the bore, passes the internal shoulder and cuts during a controlled reverse-feed movement.

Standard models cover cutting diameters from Ø2.8 to Ø5.9 mm, cutting widths of 1.3 and 1.5 mm, and clearance lengths from 10 to 22 mm. The one-piece carbide construction provides the rigidity and dimensional stability required for restricted-access internal machining.

Key Product Features

• Reverse-Feed Back TurningDesigned to pass an internal shoulder and machine the rear face or recessed feature during reverse tool movement.
• 30° Cutting GeometryThe defined cutting geometry provides clearance for controlled back turning and internal undercut machining.
• Small-Bore AccessibilityCutting diameters from Ø2.8 mm provide access to rear-facing features in miniature and precision-turned components.
• Rigid Solid Carbide BodyFine-grain solid carbide construction helps control tool deflection and supports repeatable rear-face dimensions.

Typical Applications

Aplicación Machining Purpose
Internal Back Turning Machining a rear-facing internal surface by cutting in the reverse feed direction.
Rear Shoulder Finishing Finishing the back face of an internal shoulder that cannot be reached with a conventional boring bar.
Internal Undercutting Producing controlled relief features and recessed areas behind internal shoulders.
Recessed Feature Machining Machining hidden or restricted internal features after the cutting edge passes through the bore entrance.

Micro Internal Machining Methods

Micro internal boring grooving threading profiling and back turning methods

Recommended Workpiece Materials

Best ApplicationCarbon steel, alloy steel, stainless steel and copper alloys.
Suitable ApplicationPre-hardened steel, hardened steel below approximately 48 HRC, cast iron and titanium alloys. Application-specific coated versions are available for titanium alloys and other difficult-to-machine materials.
MXR micro back turning bar workpiece material application guide

Compatibilidad de la máquina

CNC Turning Centers
Internal back turning and recessed features.
Swiss-Type Lathes
Miniature and high-volume precision parts.
Automatic Lathes
Repeatable machining of internal rear faces.
Precision Manual Lathes
Prototype and small-batch internal machining.

Product Detail Photos

MXR Series Solid Carbide Micro Back Turning Bars for Small Bore Internal Machining 1 MXR Series Solid Carbide Micro Back Turning Bars for Small Bore Internal Machining 3MXR Series Solid Carbide Micro Back Turning Bars real photoMXR Series Solid Carbide Micro Back Turning Bars applicationMXR Series Solid Carbide Micro Back Turning Bars for Small Bore Internal Machining 5MXR Series Solid Carbide Micro Back Turning Bars for Small Bore Internal Machining 7

Product Video

Back-Turning Toolpath

1. Enter the BoreMove the tool through the bore with sufficient radial clearance.
2. Pass the ShoulderPosition the cutting edge behind the internal shoulder or recessed feature.
3. Move to Cutting PositionApply the programmed radial movement only after the cutting edge has cleared the shoulder.
4. Cut in ReverseMachine the rear face using the specified reverse-feed direction, then retract safely.
micro boring bars carbide internal tooling all sereis Solid carbide micro boring bars with bronze, black, gray-black, champagne and rainbow coatings for different workpiece materials.

Selection Recommendation

Select the MXR model according to cutting diameter d1, nose radius R, cutting width B, cutting depth Q, clearance length L1 and shank diameter D. Verify that the cutting edge can pass through the bore and move behind the shoulder without collision. Use the shortest practical clearance length to maximize tool rigidity.

MXR Series Specifications

The MXR Series includes solid carbide micro back turning bars for machining internal rear faces, undercuts and recessed features behind shoulders. Standard models cover cutting diameters from Ø2.8 to Ø5.9 mm. All dimensions shown below are in millimeters.

Model Designation

MXR49R020L220550
Código Meaning Example Value
MXR Tool series Micro back turning bar
49 Cutting diameter d1 Ø4.9 mm
R020 Nose radius R R0.20 mm
L220 Clearance length L1 22 mm
550 Shank diameter D and overall length L Ø5 mm shank, 50 mm overall length

Custom tools and special geometries may use different model coding. Confirm all dimensions on the approved production drawing before ordering.

Dimension Definitions

Symbol Dimension Descripción
d1 Diámetro de corte Diameter represented by the cutting edge and used to identify the MXR model size.
R Radio de la nariz Cutting-edge radius affecting edge strength, profile accuracy and surface finish.
B Cutting Width Width of the back-turning cutting geometry shown in the technical drawing.
Q Cutting Depth Catalog depth dimension available for machining the rear feature.
L1 Clearance Length Reduced-neck length available for reaching behind an internal shoulder.
D Diámetro del vástago Nominal cylindrical shank diameter used for toolholding.
L Longitud total Total length from the cutting edge to the end of the carbide shank.

Dimensions and Standard Sizes

Click the dimension chart to open the full-size image.

Standard Model Range

Modelo d1 R B Q L1 D L
MXR3.0 2.8 0.10 1.3 0.6 10 4 50
MXR4.0 3.9 0.10 1.3 0.8 10 / 15 4 50
MXR5.0 4.9 0.20 1.5 1.3 15 / 22 5 50
MXR6.0 5.9 0.20 1.5 1.8 15 / 22 6 50

Specification Range Summary

Cutting Diameter d1Ø2.8–Ø5.9 mm
Nose Radius RR0.10 / R0.20 mm
Cutting Width B1.3 / 1.5 mm
Cutting Depth Q0.6–1.8 mm
Clearance Length L110 / 15 / 22 mm
Shank Diameter DØ4 / Ø5 / Ø6 mm

Selection Guidance

1. Check Entry ClearanceConfirm that the tool tip and neck can pass through the bore before moving behind the shoulder.
2. Confirm Rear ClearanceCheck that sufficient space is available behind the shoulder for radial positioning and reverse-feed cutting.
3. Select Width and DepthThe selected cutting width B and depth Q must cover the required rear-face or undercut dimensions.
4. Minimize Tool OverhangUse the shortest practical L1 and the largest compatible shank diameter to improve rigidity.

Recommended Starting Conditions

  • Set the cutting edge accurately on the spindle centerline.
  • Confirm the spindle direction and programmed reverse-feed direction.
  • Simulate the complete entry, positioning, cutting and retraction path.
  • Do not move the tool radially into cutting position before it has cleared the shoulder.
  • Begin with a conservative cutting depth and feed, especially on the 22 mm clearance-length models.
  • Use suitable coolant or compressed air to prevent chip accumulation behind the shoulder.
  • Reduce the cutting load if vibration, taper or rear-face dimensional variation occurs.

Related Micro Internal Tool Series

Internal Profiling: MUR Series

Complex Profiling: MQR Series

General Internal Boring: MTR Series

Internal Grooving: MGR Series

We support distributors, tooling suppliers and industrial partners with flexible OEM and private label solutions for micro internal tooling products. From laser marking and customized packaging to product identification and technical documentation, we help customers build their own tooling product lines with reliable manufacturing support.

OEM Product Scope

We provide OEM and private label manufacturing solutions for micro internal tooling products, supporting distributors and tooling suppliers with standard series, customized specifications and drawing-based production.

● Micro Boring Bars

MPR series and customized small-diameter boring tools for precision internal machining and anti-vibration applications.

● Micro Internal Threading Bars

MIR/MIL series with customized thread profiles, dimensions and product identification requirements.

● Micro Grooving Tools

Internal grooving and special groove solutions for miniature precision components.

● Custom Micro Tooling

Non-standard dimensions, special geometries and customer drawing-based tooling solutions are available.

mini boring bars

Customization Options

Custom laser marking for micro internal tooling

Laser Marking & Product Identification

Custom logo, model number and product identification marking can be provided according to distributor and brand requirements.

Custom packaging solution for micro tooling

Custom Packaging

Individual packaging, labels and product information can be customized to support reseller sales channels and private brand development.

Technical documentation support for tooling OEM

Technical Documents & Product Support

Support technical drawings, specifications and product information to help distributors promote and manage their tooling products.

OEM Workflow

01. Requirement Review

Confirm drawings, specifications, materials and packaging requirements.

02. Tool Confirmation

Finalize tool design, marking details and production requirements.

03. Sample Approval

Provide samples for testing and approval before batch production.

04. Batch Production

Produce and inspect according to confirmed requirements.

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Private Label Support for Distributors

For distributors and tooling resellers, we provide flexible private label support including customized marking, packaging solutions and product documentation to help establish a professional tooling product range.

We follow strict quality control procedures from raw material inspection to final shipment. Each tool is inspected to ensure consistent dimensions, cutting performance and reliable quality for industrial machining applications.

Proceso de control de calidad

Quality control inspection for carbide cutting tools
01 Material Inspection

Verify carbide material quality and consistency before production.

02 Precision Grinding Control

Control tool geometry, dimensions and cutting edge accuracy during manufacturing.

03 Cutting Edge Inspection

Inspect edge quality and surface finish to maintain stable cutting performance.

04 Final Quality Inspection

Confirm product specifications before packing and shipment.

Inspection Standards

Inspection Item Purpose
Material Inspection Verify carbide quality and material consistency.
Dimension Inspection Confirm tool size and tolerance requirements.
Cutting Edge Inspection Check edge geometry and surface quality.
Final Inspection Ensure products meet confirmed specifications before delivery.

Packing & Protection

Carbide cutting tool packing and protection

Individual protection and export packaging help prevent tool damage during storage and international transportation.

  • Individual tool protection
  • Product identification labels
  • Batch traceability support
  • Export shipment protection

Production & Delivery Workflow

01

Confirmación del pedido

02

Production Scheduling

03

Quality Inspection

04

Packing

05

Shipment

export packing way hy cutting toolsShipping and payment hy cutting tools end mill drills

Delivery Support

Standard products can usually be shipped within 1–3 working days after order confirmation. Customized products require confirmation according to tool design, quantity and production requirements.

FAQ & Downloads

Product FAQs

What are MXR micro back turning bars used for?
MXR solid carbide micro back turning bars are designed for machining rear-facing surfaces, internal undercuts and recessed features behind shoulders in small-diameter bores. The tool passes through the bore and machines the feature using a controlled reverse-feed movement.
What cutting diameters are available?
Standard MXR models cover cutting diameters from Ø2.8 to Ø5.9 mm. Available shank diameters include Ø4, Ø5 and Ø6 mm, with clearance lengths of 10, 15 and 22 mm depending on the model.
What cutting widths and depths are available?
Standard cutting widths B are 1.3 and 1.5 mm. Depending on the model, the catalog cutting depth Q ranges from 0.6 to 1.8 mm. Both dimensions should be compared with the required rear-face or undercut geometry.
What does the 30° geometry represent?
The 30° value identifies the back-turning cutting geometry shown in the technical drawing. It provides clearance for machining behind an internal shoulder. The component geometry and complete tool path must still be checked before machining.

Selection & Application FAQs

How do I select the correct MXR back turning bar?
Select the model according to cutting diameter d1, nose radius R, cutting width B, cutting depth Q, clearance length L1 and shank diameter D. Verify that the tool can enter the bore, pass the shoulder and move into the cutting position without collision.
How is an MXR tool different from a conventional boring bar?
A conventional boring bar normally machines the bore diameter and forward-facing internal surfaces. The MXR cutting edge is oriented for reverse-feed machining of rear faces and recessed features positioned behind an internal shoulder.
What materials can be machined with MXR back turning bars?
Typical applications include carbon steel, alloy steel, stainless steel and copper alloys. Selected tools can also machine pre-hardened steel, cast iron and titanium alloys. Application-specific coated versions are available for titanium and other difficult-to-machine materials.
How can I prevent a collision during back turning?
Simulate the complete entry, radial positioning, reverse cutting and retraction sequence before production. Do not move the tool radially into the cutting position until the cutting edge has completely passed the internal shoulder.
How can I improve machining stability?
Use the shortest practical clearance length and tool overhang, select the largest shank diameter permitted by the bore, and use a high-precision holder. Reduce the cutting depth and feed if vibration or rear-face dimensional variation occurs.

Ordering & OEM FAQs

Can you manufacture custom MXR back turning bars?
Yes. Cutting diameter, nose radius, cutting width, cutting depth, back-turning profile, clearance length, shank diameter, coating and overall length can be customized according to the component drawing or application requirements.
Can I order mixed models or trial quantities?
Yes. Mixed-model requirements and small trial orders can be reviewed according to the selected sizes and available stock. The standard minimum order quantity is normally 10 pieces, subject to final model confirmation.
Is OEM marking and private-label packaging available?
Yes. OEM services can include laser marking, custom model identification, private labels and distributor packaging. Please provide the logo file, marking position and packaging requirements when requesting a quotation.
What information is required for a quotation?
Please provide the standard model or component drawing, bore entrance diameter, shoulder diameter, rear-face width, machining depth, workpiece material, tolerance, quantity and any coating, marking or packaging requirements.
What is the lead time for MXR back turning bars?
In-stock standard models can normally be dispatched within 1–3 working days after order confirmation. Customized tools require separate lead-time confirmation according to the geometry, coating, quantity and inspection requirements.

Recursos técnicos

Catálogo de microherramientas internas HY Micro Internal Tooling Catalog (PDF)

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