Ever struggled to get that perfect textured grip on your metal projects? Cutting with a knurling tool can seem tricky if you’re new to machining or just looking to refine your technique. Mastering this skill opens the door to safer, more professional-looking tools and parts.
In this article, you’ll discover exactly how to use a knurling tool, step-by-step instructions, and practical tips to ensure sharp, consistent results every time.
Related Video
How to Cut with a Knurling Tool: A Comprehensive Guide
Cut knurling is an essential technique for achieving precise, high-quality patterns on cylindrical workpieces. Unlike form knurling—which displaces metal by pressing—it actually removes material, resulting in crisp, sharp knurls. In this guide, you’ll learn what cut knurling is, how to use a cut knurling tool, and tips for success, along with common questions and their answers.
What Is Cut Knurling?
Cut knurling involves machining a pattern—often straight, diamond, or cross-hatch—onto the surface of a workpiece using special wheels. Instead of compressing the material, the cutting knurling tool actually shears away metal to create clean, well-defined grooves. This technique is commonly used on lathes.
Why Use Cut Knurling?
- Crisper edges: Cut knurls have sharper, deeper, and more consistent profiles.
- Less force: It requires less pressure on the part and the machine, reducing stress and the risk of bending slender or soft components.
- Works with harder materials: Unlike form knurling, cut knurling is better suited for tough or brittle metals.
Tools and Setup for Cut Knurling
To successfully cut knurls, you’ll need:
- A lathe capable of steady, consistent speeds.
- Cut knurling tool holder, designed to position and support the cutting wheels.
- High-quality cut knurling wheels, available in various pitch and patterns.
- Appropriate workpiece material, such as steel, stainless steel, brass, or aluminum.
Basic Setup Steps
- Prepare the Workpiece:
- Ensure the material is cylindrical.
- Clean it to remove oil or debris.
- Select the Knurl Pattern and Pitch:
- Choose the wheel pattern (straight, diamond, etc.) based on your desired result.
- Match the pitch to your workpiece diameter for even patterning.
- Mount the Tool:
- Secure the cut knurling tool into the lathe holder.
- Align it so the wheels are perpendicular to the workpiece for consistent cuts.
- Double-Check Alignment:
- Misalignment may cause double-tracking or poor definition.
How to Cut Knurling: Step-by-Step
Here’s a step-by-step guide to getting sharp, professional results:
- Set Lathe Speed:
- Use lower speeds, typically 60-200 RPM, depending on material hardness.
- For harder materials, use slower speeds to avoid tool wear and chatter.
- Position the Cutting Wheels:
- Bring the wheels gently into contact with the rotating workpiece.
- Engage both wheels at the same depth for symmetrical results.
- Engage the Feed:
- Set the lathe to automatic feed mode.
- Ensure the feed rate matches the pitch of the knurl pattern.
- Start the Cut:
- Gradually feed the tool into the workpiece. Do not rush the process to avoid tool damage.
- Maintain steady pressure as the pattern develops.
- Monitor Progress:
- Watch for build-up or chatter.
- If chips do not clear naturally, pause and clean them out.
- Reverse Feed:
- For double-sided knurling tools, reverse direction to complete the pattern.
- Finish and Inspect:
- Once desired depth is achieved, retract the tool.
- Inspect pattern sharpness and depth.
- Deburr the workpiece edges if necessary for safety.
Benefits of Cut Knurling
Cut knurling offers several advantages over form knurling:
- Better Quality: Produces highly defined and repeatable patterns.
- Material Range: Effective with almost any machinable metal.
- Less Distortion: Reduces risk of warping or deforming thin parts.
- Easier on Equipment: Lower operational forces mean less wear on your machine.
Common Challenges and How to Overcome Them
Despite its many benefits, cut knurling has a few unique challenges:
1. Wheel Wear
- Challenge: Knurling wheels can dull or chip, especially with tough materials.
- Solution: Use quality wheels and replace or re-sharpen them regularly.
2. Chatter and Surface Finish
- Challenge: Excessive vibration can ruin the pattern.
- Solution: Reduce speed, increase rigidity, and make sure the tool and workpiece are solidly clamped.
3. Double-Tracking
- Challenge: The pattern does not align with itself, causing a double image.
- Solution: Carefully match the workpiece diameter and knurl pitch. Precise alignment is vital.
4. Chip Build-Up
- Challenge: Chips may clog the knurling teeth.
- Solution: Pause and use a brush or air blast to clear chips from the tool and workpiece.
Practical Tips and Best Practices
- Lubrication: Use cutting oil or coolant to reduce friction, improve tool life, and produce a cleaner finish.
- Tool Maintenance: Regularly inspect the knurling tool and holders for wear or misalignment.
- Consistent Feed: Maintain steady feed rates for an even pattern depth.
- Test Before Production: Try your setup on scrap material before starting your final workpiece.
- Choose the Right Tool Holder: Some knurling tool holders are designed with built-in adjustments for ease of use and consistency.
Cost and Shipping Tips
If you are purchasing cut knurling tools or holders:
- Buy Quality: Higher-grade wheels and holders may cost more upfront but last longer and produce better results.
- Look for Bundles: Some suppliers offer kits including multiple wheels and holders, often at a savings.
- Consider Shipping Options: When ordering from industrial suppliers or toolmakers, compare shipping rates and times.
- Local Distributors: Purchasing from local suppliers can save on shipping costs and reduce wait time.
- Bulk Orders: If your shop uses cut knurling tools frequently, ordering in bulk may provide discounts and lower overall shipping fees.
Frequently Asked Questions (FAQs)
1. What is the main difference between cut knurling and form knurling?
Cut knurling removes material using sharp wheels to create a pattern, while form knurling compresses the surface to imprint the design. Cut knurling produces sharper, cleaner patterns and is better for harder materials or delicate workpieces.
2. Can I use cut knurling on any type of metal?
Cut knurling works on most machinable metals, including steel, stainless steel, brass, and aluminum. It is especially useful for hard or brittle materials where form knurling may cause distortion.
3. What lathe speed should I use for cut knurling?
Lower speeds, typically 60-200 RPM, are best. Adjust speed based on the hardness of the material and the size of your workpiece. Slower speeds help prevent overheating and tool wear.
4. How do I prevent double-tracking on my knurl pattern?
To prevent double-tracking, carefully match the workpiece diameter with the knurl pitch, and ensure your tool is aligned perpendicular to the workpiece. Take your time during setup and verify alignment before starting the cut.
5. How do I maintain my cut knurling tools for long life?
Regularly clean your tools after use, inspect the cutting wheels for chips or wear, and replace them as needed. Proper lubrication during cutting also extends tool life and maintains pattern quality.
Summary
Cut knurling is a precise, effective method for adding professional patterns to cylindrical parts. It produces cleaner, deeper, and more durable patterns compared to form knurling. By following the right steps—choosing quality tools, setting up carefully, and maintaining your equipment—you can achieve excellent results every time. Remember to test your settings on scrap, use lubrication, and keep your tools clean for the best knurling experience.