Overview of Carbide Brazed Blanks
Carbide brazed blanks are an innovative type of cutting tool substrate made by brazing a carbide alloy onto a steel shank. They combine the hardness and wear resistance of carbide with the toughness and machinability of steel.
Some key features of carbide brazed blanks:
- Hard carbide alloy providing wear resistance is brazed to tough and machinable steel shank.
- Allows complex tool geometries to be machined into the steel shank.
- Wide range of carbide grades and coatings available.
- Simpler manufacturing than solid carbide tools.
- Lower cost alternative to solid carbide tools.
- Used for high production machining applications.
Carbide brazed tools are ideal for hard milling, turning, drilling and other cutting operations on steels, high temperature alloys, and hard-to-machine materials. They are commonly used in automotive, aerospace, die & mold, oil & gas industries.
Types of Carbide Brazed Blanks
There are two main types of carbide brazed blank configurations:
Tip Brazed Blanks
- Carbide tip is brazed to front end of steel shank.
- Provides wear resistance only at cutting tip.
- Simpler brazing method.
- Lower cost than full carbide tools.
- Used for light machining applications.
Full Face Brazed Blanks
- Entire front face is brazed with carbide.
- Maximizes wear resistance.
- Withstands heavy machining.
- Allows complex geometries.
- Higher cost than tip brazed tools.
- Used for heavy duty machining.
| Tip Brazed Blanks | Full Face Brazed Blanks |
|---|---|
| Carbide tip only | Full carbide brazed face |
| Light machining | Heavy machining |
| Lower cost | Higher cost |
| Simple brazing | Complex brazing |
Characteristics of Carbide Brazed Blanks
Key characteristics and design considerations for carbide brazed blanks:
- Carbide grade – Varies from fine grain grades for high hardness to more fracture resistant grades. Controls wear resistance and toughness.
- Carbide thickness – Thicker carbide layer improves wear life but can reduce toughness. Typical thickness 0.8mm to 3mm.
- Braze material – Nickel based alloy with high temperature brazing. Crucial for carbide-steel bond strength.
- Shank material – Medium/high carbon steel provides strength and machinability. Can be heat treated.
- Shank diameter – Available in standard sizes from 3mm to 32mm dia. Match to toolholder.
- Shank geometry – Cylindrical, square or hexagonal. Impacts stiffness and machining access.
- Coatings – TiAlN, TiN, TiCN, AlCrN used for higher hardness, heat resistance and friction reduction.
| Parameter | Options |
|---|---|
| Carbide grade | Fine, medium, coarse grain |
| Carbide thickness | 0.8mm to 3mm typically |
| Braze material | Nickel based high temp alloy |
| Shank material | Medium/high carbon steel |
| Shank diameter | 3mm to 32mm standard sizes |
| Shank geometry | Round, square, hexagonal |
| Coatings | TiAlN, TiN, TiCN, AlCrN |
Applications of Carbide Brazed Tools
Carbide brazed blank tools are designed for the following machining applications:
- Turning – Excellent for high production turning of steel and alloy parts. Used for roughing, finishing, grooving, threading.
- Milling – For face milling, slotting, side & face milling of steels, titanium and nickel alloys.
- Drilling – Provides good hole quality and tool life for deep hole drilling in alloy steels.
- Threading – Carbide tipped blanks ideal for high volume tapping applications.
- Reaming – Finish reamers made from full face brazed blanks for steel components.
- Boring – Better boring accuracy in steel parts versus high speed steel.
| Application | Uses |
|---|---|
| Turning | Roughing, finishing, grooving, threading |
| Milling | Face, slot, side & face milling |
| Drilling | Deep hole drilling in steels |
| Tapping | High volume tapping |
| Reaming | Finish reaming in steels |
| Boring | Boring in alloy steels |
Specifications of Carbide Brazed Blanks
Typical specifications and design standards for carbide brazed blank tools:
| Parameter | Specifications |
|---|---|
| Carbide grades | ISO K, P, M, H10-H40 |
| Carbide thickness | 0.8-3mm |
| Braze material | ISO 3613 Ni alloy |
| Shank hardness | Up to 60 HRC |
| Shank tolerances | ISO 2768 |
| Shank diameter | 3-32mm |
| Shank geometry | ISO 698, 13399 |
| Coatings | ISO 2316, 3325, 3326 |
- Carbide grade follows ISO 513 classifications from fine micrograin (K) to coarse (H).
- Shank production tolerances per ISO 2768 medium tolerance class.
- Shank dimensions and fits follow ISO 698 and 13399 standards.
- Coatings conform to ISO coating standards.
Suppliers and Cost of Carbide Brazed Blanks
Carbide brazed blanks are available from tooling manufacturers and tool suppliers. Here are some sample suppliers and prices:
| Supplier | Shank Size | Carbide Grade | Cost |
|---|---|---|---|
| Kennametal | 1/2″ dia x 4″ | KC725M | $45 |
| Mitsubishi | 20mm dia x 75mm | VP15TF | $60 |
| Sandvik Coromant | 16mm sq x 100mm | GC4215 | $75 |
| Walter Tools | 3/4″ sq x 5″ | H10F | $55 |
| WIDIA | 25mm dia x 150mm | KC5500 | $90 |
- Cost range is approximately $45 to $100 per blank depending on size and grade.
- Economical versus solid carbide costing 2X to 5X more.
Installation of Carbide Brazed Tools
Steps for installing and using carbide brazed blank tooling:
1. Inspect – Check carbide edge, braze joint, shank condition.
2. Measure – Confirm shank is within tolerance for tool holder bore.
3. Clean – Remove any debris, grease from holder bore, shank.
**4. Insert – Place coated shank into cleaned holder. Avoid touching brazed edge.
5. Tighten – Tighten holder even and firmly per manufacturer torque setting.
6. Check – Verify secure tool clamping, no movement in holder.
7. Set heights – Set working heights, lengths per application. Account for brazed edge.
8. Check runout – Test runout to ensure tool concentricity.
| Step | Procedure |
|---|---|
| 1 | Inspect tool |
| 2 | Measure shank size |
| 3 | Clean holder & shank |
| 4 | Insert into holder |
| 5 | Tighten holder |
| 6 | Check clamping |
| 7 | Set working heights |
| 8 | Check runout |
Operation and Maintenance
Follow these carbide brazed blank best practices:
- Choose suitable carbide grade and coating for workpiece material. Harder carbide for harder metals.
- Reduce speeds/feeds if carbide edge chips or cracks form. Maintain sharp cutting edge.
- Use heavy depths of cut that suit rigid shank and thick carbide. Reduce for small diameters.
- Apply correct insert geometries for turning, facing, boring based on operation.
- Ensure holder and machine have sufficient rigidity to avoid edge chipping.
- Replace worn inserts promptly. Re-sharpening not typically done.
- Avoid rubbing on workpiece, especially with coated edge. Prevent edge buildup.
- Clean chips from tool regularly to minimize carbide temperature. Use coolant if possible.
| Practice | Description |
|---|---|
| Proper carbide grade | Match grade to work material |
| Adjust speeds/feeds | Prevent carbide chipping |
| Use heavy depths of cut | Suit thick carbide and rigid shank |
| Correct insert geometry | Per turning, milling, boring etc. |
| Rigid setup | Prevent brazed edge chipping |
| Replace worn inserts | Don’t re-sharpen |
| Avoid rubbing workpiece | Prevent edge buildup |
| Clean chips regularly | Control carbide temperature |
How to Select Carbide Brazed Tool Suppliers
Follow these guidelines for choosing carbide brazed blank suppliers:
- Select established tooling manufacturers with proven brazing methods.
- Ensure supplier has suitable carbide grades and coatings for your applications.
- Consider custom blank engineering services for optimal tool design.
- Choose suppliers able to produce complex carbide geometries if required.
- Request samples to test tool performance before full purchase orders.
- Review technical data sheets for accurate tool specifications and tolerances.
- Compare prices from multiple vendors to get competitive quotes.
- Consider total value – service, delivery, quality rather than just lowest cost.
- Seek suppliers able to meet potential high volume production demands.
- Confirm braze joint warranty and insert replacement policy.
| Guideline | Description |
|---|---|
| Proven manufacturers | Use reliable brazing methods |
| Suitable materials | Grades and coatings for your needs |
| Custom engineering | Optimize tool design |
| Complex geometries | If required for your parts |
| Test samples first | Validate performance before full purchase |
| Review technical data | Confirm specifications |
| Compare prices | Get quotes from multiple vendors |
| Consider total value | Not just lowest cost |
| Meet volume demands | Scale up production |
| Warranty on braze joint | Insert replacement policy |
Pros and Cons of Carbide Brazed Tools
Advantages of Carbide Brazed Blanks:
- Low cost alternative to solid carbide tools.
- Tailorable carbide grades and coatings for specific applications.
- Complex cutting geometries can be ground into steel shank.
- Productivity benefits of carbide at lower price point.
- Consistent quality from advanced brazing methods.
- Good performance in high production environments.
- Easier to clamp and index versus small solid carbide tools.
Limitations of Carbide Brazed Blanks:
- Not as robust as solid carbide tools for extreme machining.
- Limited edge toughness and thicker cutting geometry versus solid carbide.
- Brazed edge integrity subject to quality control of brazing process.
- Still more expensive than high speed or tool steel tools.
- Re-sharpening not practical. Worn inserts must be replaced.
- Small diameters have size and geometry limitations.
| Advantages | Disadvantages |
|---|---|
| Lower cost than solid carbide | Less robust than solid carbide |
| Tailorable grades and coatings | Thicker geometry than solid carbide |
| Complex cutting geometries | Braze quality dependent on process control |
| Productivity of carbide | More costly than steel tools |
| Consistent braze quality | No re-sharpening |
| Good for high production | Size limits at small diameters |
Carbide Grades for Brazed Tools
Carbide alloys used in brazed tools offer a range of hardness, wear resistance, toughness and temperature properties. Key carbide grades include:
- K grades – Very fine micrograin with highest hardness and wear resistance. Brittle, used for light finishing cuts.
- P grades – Fine grain with good hardness and toughness balance. For steel machining.
- M grades – Medium grain for versatility across materials, suitable for roughing.
- H grades – Coarse grain grades from H10 to H40. Tougher for intermittent cuts.
| Grade | Hardness | Wear Resistance | Toughness | Best Uses |
|---|---|---|---|---|
| K | Very high | Excellent | Low | Finishing steels |
| P | High | Very good | Moderate | Steels |
| M | Medium | Good | Higher | Roughing, steels, alloys |
| H | Low-medium | Fair | Best | Interrupted cuts |
The choice of carbide grade depends on workpiece material, cutting pressures, and whether an application is continuous or interrupted cutting. A reputable carbide brazed tool supplier can recommend the optimal grade for specific applications.
Carbide Coatings for Brazed Blanks
A range of coatings are applied to the carbide tip and edge via PVD or CVD deposition processes. Common options include:
- TiAlN – Titanium aluminum nitride. Provides high hardness up to 3500 HV and heat resistance to 1000°C. Good general purpose coating.
- TiN – Titanium nitride. Imparts a gold color. Hardness around 2000 HV. Good corrosion and adhesion resistance.
- TiCN – Titanium carbon nitride. Hardness of 3000 HV. Excellent abrasion resistance. Used for high production machining of steels and cast irons.
- AlCrN – Aluminum chromium nitride. Temperature resistance over 1000°C. Oxidation and adhesion resistant. Used for high feed milling and drilling.
| Coating | Hardness HV | Temperature | Key Features |
|---|---|---|---|
| TiAlN | 3500 | 1000°C | High hardness and heat resistance |
| TiN | 2000 | 800°C | Corrosion resistant, lubricious |
| TiCN | 3000 | 800°C | Abrasion resistant |
| AlCrN | 2800 | 1000°C+ | Oxidation resistant |
Coatings enhance wear life, lubricity, and heat resistance. Multiple coats are sometimes applied. The coating choice depends on work material and cutting conditions.
Carbide Brazed End Mills
Carbide brazed end mills provide an economical option for face milling, slotting, side milling, and contouring operations on steels and alloys. Some examples include:
- Face mills – Full face carbide brazed for heavy milling. Helical flute design preferred.
- Square end mills – For slot and pocket milling. Available in various lengths and carbide grades.
- Ball nose end mills – For 3D contour profiling with smaller corner radii available.
- Chamfer mills – Angled cutting edge to mill chamfers and angled faces.
| Type | Uses | Features |
|---|---|---|
| Face mills | Heavy facing | Full carbide face, helical flute |
| Square end mills | Slot/pocket milling | Lengths up to 8x diameter |
| Ball nose mills | 3D contouring | Small corner radii |
| Chamfer mills | Chamfers, angles | Angled cutting edge |
Brazed end mills provide cost-effective tool life relative to high speed steel, with better performance in alloy steels. Proper speeds, feeds, depths must be applied.
Carbide Brazed Turning Inserts
Indexable carbide inserts made from brazed blanks have advantages for high production CNC turning of steels and alloys. Some options are:
- External Turning – Positive rake inserts for facing, straight turning, profiling.
- Internal Turning – Negative rake inserts with thicker centerline for boring bars.
- Threading – Ground chipbreaker geometries for tapping and thread turning.
- Grooving – Inserts with sharper cutting edge, radiused corner.
- Parting – Narrow inserts to optimize parting off process. Thin profile inserts also.
| Turning Operation | Insert Features |
|---|---|
| External turning | Positive rake, sharp edges |
| Internal turning | Negative rake, stronger core |
| Threading | Ground chipbreakers |
| Grooving | Sharp edge, radiused corner |
| Parting | Narrow width, thin profile |
Indexable inserts allow multiple cutting edges to be used cost effectively. Tool holders properly position and secure the inserts during turning operations.
FAQ
Q: Are carbide brazed tools as strong as solid carbide tools?
A: No. Solid carbide tools are typically stronger in terms of edge toughness and resistance to chipping. However, modern carbide brazed tools can approach solid carbide performance while being more cost effective. Proper selection of carbide grade and application is key.
Q: Can carbide brazed tools be sharpened?
A: Typically no. The hard brazed carbide edge does not allow re-sharpening by grinding. The benefit is that inserts are simply replaced when worn, returning the tool to like-new condition.
Q: What causes carbide edges to chip or break?
A: Excessive cutting forces, speeds/feeds, or depths for a given carbide grade can cause fracturing. Insufficient workpiece rigidity or tool clamping can also contribute to edge chipping. Proper selection of cutting parameters and tool/work setup is critical.
