Ultra-machining efficiency and stability in steel applications

- Takahiro Yamamoto, OSG Corporation Applications Engineer (Drill Development Division)

Three-flute drills are commonly employed in manufacturing. However, they are mostly used in the processing of materials with short cutting chips and low cutting resistance, such as cast iron, ductile cast iron and aluminum alloy. Three-flute drills are sometimes advertised to be suitable for steel materials such as carbon steel, alloy steel and mild steel. However, with a smaller chip room geometry than 2-flute drills, the cutting thrust resistance in 3-flute drills is also greater.

Due to constraints in workpiece configuration, equipment and setup, conventional 3-flute drills often are unable to maximize both speed and precision as advertised. Moreover, in steel processing, the strength of the work material and viscosity are high, making chip separation and stable processing a challenge. With high thrust force and poor chip evacuation, sudden machining troubles such as tool breakage and chipping are common headaches of 3-flute drills.

To help manufacturers maximize productivity, OSG has recently introduced a new revolutionary drilling innovation – the ADO-TRS – nicknamed as the ‘Triple Revolution’ drill, for ultra-machining efficiency and stability in steel materials.

Features of ADO-TRS ‘Triple Revolution’ Drill

There are three major features that enable the ADO-TRS to stably process steel applications.

The most notable key feature is the newly engineered R gash geometry (pat. P) as illustrated in figure 1.

Figure 1. ADO-TRS’ unique R gash geometry enables low cutting resistance and creates short and compact chips stably.

The optimized R shape geometry is designed to control chip flow direction to facilitate trouble-tree chip-evacuation. With this new feature, the ADO-TRS is able to significantly improve chip separation even in steel materials by breaking them into small pieces and consistent shape. In addition, this new geometry can reduce cutting resistance (thrust resistance), by as much as 30 percent versus conventional tooling, enabling it to outperform even 2-flute drills in high-feed processing with minimal cutting resistance.

The second key feature of the ADO-TRS is its wide chip pocket configuration.

In 3-flute drills, chips are difficult to be discharged from the center of the drill. The ADO-TRS employs a wide chip room flute geometry to improve chip ejection. Combined with the R gash specification, chips are curled for greater separation capability, which leads to smooth and stable chip evacuation.

Last but not least, the ADO-TRS is coated with OSG’s original EgiAs coating for high durability. The EgiAs coating is consist of overlapping nano-periodical layers and wear-resistance layers, engineered to suppress the propagation of cracks that are likely to occur during drilling. The wear-resistance layer is composed of multiple hard layers; while the nano-periodical is a combination of hard and soft layers. With a mixture of hard and soft layers, internal stress can be relieved, allowing the EgiAs coating to achieve both high wear resistance and extreme toughness to ensure stable and consistent tool life under aggressive cutting conditions.

Cutting Data

1. Excellent Chip Formation and Evacuation in Steel Applications

Two of ADO-TRS’ most notable benefits are its superior chip management and low resistance drilling capability in steel materials.

SCM440 (raw) is one of the more viscous materials among steels. When processing this material with MQL, chips generated by conventional 3-flute drills and 2-flute drills are elongated as depicted in figure 2. As depicted in figure 3, the conventional 3-flute drill is unable to break chips into small pieces. As a result, remnants of elongated chips remain in the flute of the drill. The ADO-TRS, on the other hand, is able to demonstrate excellent chip form consistently as shown in figure 2.

Figure 2. Chip shape comparison in SCM440.

Figure 3. Condition of the conventional 3-flute drill after processing SCM440.

Figure 4. Chip shape comparison in SS400

Figure 5. Tool life comparison in SS400

Moreover, in the processing of SS400 using water-soluble coolant, sudden tool damage and chipping caused by tangled chips are prone to occur. The stability in chip formation and evacuation is a key factor for achieving stable processing in mild steel SS400, which is particularly prone to chip problems. As illustrated in figure 4 and figure 5, the ADO-TRS demonstrates overwhelming chip separation capability and long tool life even in the processing of SS400 in comparison to the conventional 3-flute drill and 2-flute drill.

2. Low Resistance Drilling

Next, figure 6 illustrates a comparison of cutting resistance when processing under the cutting condition depicted in figure 2.

Figure 6. Cutting resistance (thrust resistance) comparison in SCM440.

As shown in figure 6, the ADO-TRS is able to reduce thrust resistance by approximately 35 percent versus conventional 3-flute drills, and generated even less overall thrust resistance when compared to a standard 2-flute carbide drill, which has one less flute and larger chip rooms. Under identical cutting condition, the ADO-TRS is able to achieve the lowest thrust resistance.

Due to high cutting resistance inherent in conventional 3-flute drills and the various constraints present in processing environment, such as the machine, workpiece geometry, work fixture, etc., conventional 3-flute drills are often unable to maximize high-feed performance and precision. The ADO-TRS, on the other hand, excels in wide range of cutting conditions, truly reflecting its versatile capability.

Next, we will evaluate the performance of the above features combined with OSG’s original EgiAs coating in the following case study, where the ADO-TRS is able to demonstrate long tool life and stable processing in a crankshaft made of alloy steel. In terms of shape, although the work holding force (clamp) at the time of processing is not high, the effect of the low cutting resistance of the ADO-TRS is able to surpass the carbide 2-flute drill with greater feed-rate. As shown in figure 7, the ADO-TRS is able to achieve higher efficiency and significantly reduce processing time versus the competitor 2-flute drill.

Figure 7. Case study of machining time and tool life improvement in the processing of an automotive crankshaft.

As depicted in this case study, the ADO-TRS is able to demonstrate exceptional stability, high-productivity, long tool life in steel materials, which conventional tools are challenged by instability. Furthermore, with capabilities to resolve common challenges of 3-flute drills such as high thrust force and poor chip evacuation in steel applications, the ADO-TRS is setting a new standard for 3-flute drills with reliable performance never witnessed before in the cutting tool sector.

The ADO-TRS’ unique R gash geometry feature has also been applied to OSG’s ADO 40xD and 50xD carbide drills with through coolant for highly efficient deep-hole drilling. The R gash geometry enables super low cutting resistance and exceptional chip control, optimized for superior performance in ultra-deep-hole applications. This geometry has proven success not only in 3-flute drills, but also in 2-flute drills. OSG will look to apply its superior tooling geometry to other products to further enhance productivity, tool life, stability and precision.

For manufacturers who are especially struggling with chip evacuation problems in steel applications, look to the ADO-TRS to experience ultra-machining efficiency and stability.

The ADO-TRS is available from diameter 3 mm up to 20 mm, in processing depth of 3xD and 5xD, and is suitable for applications in carbon steels, alloy steels, mild steels, cast iron and hardened steels.

Photo Captions

ADO-TRS.The ADO-TRS ‘Triple Revolution’ is OSG’s latest drilling innovation for ultra-machining efficiency in a wide range of materials. Its unique R gash geometry enables high thrust resistance and exceptional chip control, which are common challenges of 3-flute drills.

ADO-40xD 50xD. The ADO-TRS’ unique R gash geometry feature has also been applied to OSG’s ADO 40xD and 50xD carbide drills with through coolant for highly efficient deep-hole drilling. The R gash geometry enables super low cutting resistance and exceptional chip control, optimized for superior performance in ultra-deep-hole applications.

A Brand is OSG’s premium tooling brand that represents the quality assurance OSG guarantees to each and every customer. A Brand products (A-Drills, A-Taps and A-End Mills) are designed to exceed the evolving manufacturing needs of our customers. The A-Drill series features EXOCARB^® AD, ADO, ADO-SUS and ADF. Experience the level of quality, reliability and satisfaction that can only be delivered by OSG’s A Brand tooling master class!

EXOCARB^® AD & ADO 2D-30D

The EXOCARB^® AD & ADO feature superior point strength with low cutting force are achieved to accommodate a wide range of carbide drilling applications. EgiAs coating constructed with extreme toughness, high wear and heat resistance characteristics ensure stable and consistent tool life. The EXOCARB^® ADO offers a coolant-through option for those with coolant capabilities.

AD & ADO Features

• EgiAs Coating for exceptional wear resistance and toughness
• Coolant-Through (ADO) for longer tool life and smooth chip evaluation
• Optimized Drill Geometry For Every Drilling Depth
  • Wavy Point Form (2D-8D) reduces thrust and torque while creating smaller more manageable chips
  • Straight Point Form (10D-30D) enhances cutting edge strength while reducing cutting forces
  • Wide Flutes (2D-8D) facilitates stable chip evacuation
  • Middle Margin (8D-30D) improves stability in deep-hole applications

AD Line-Up

• List 6300 – 2D
• List 6310 – 4D

ADO Line-Up

• List 6500 – 3D
• List 6510 – 5D
• List 6520 – 8D
• List 6530 – 10D
• List 6535 – 15D
• List 6540 – 20D
• List 6550 – 30D

EXOCARB^® ADO-SUS 3D & 5D

Work hardening, welding, elongation of cutting chips and poor thermal conductivity are common problems in the machining of stainless steels and titanium alloys. The ADO-SUS is a carbide drill series that employs a unique coolant hole shape and tool geometry to enable efficient drilling in these difficult-to-machine materials.

ADO-SUS Features

• Patented "MEGA COOLER" Coolant Holes drastically increase coolant flow, suppressing heat generation and enhancing chip evacuation
• Patented Flute Geometry forms ideal chips for efficient chip evacuation
• Patented Cutting-Edge Geometry reduces work hardening
• WXL Coating provides superior heat and wear resistance for long tool life

ADO-SUS Line-Up

• List 5200 – 3D
• List 5210 – 5D

EXOCARB^® ADF 2D

Machining a flat hole traditionally required the use of an end mill and a drill. The EXOCARB^® ADF enables one-step drilling to simplify machining time and tool management. Suitable for a wide variety of drilling applications including inclined surfaces, curved surfaces, counterboring, eccentric holes, thin plates, etc.

ADF Features

• EgiAs Coating for exceptional wear resistance and long tool life
• Wide Flutes for superior chip evacuation
• Balanced Point Form for reduced thrust and improved stability
• Improved Cutting Edge reduces cutting forces and creates smaller chips

ADF Line-Up

• List 5700 – 2D

Watch our A Brand video on YouTube!

We announced the release of our new EXOCARB® ADF drills. The ADF combines two operations in one for the drilling of inclined surfaces and counterboring applications.

The ADF was developed with an “all-purpose” concept for superior versatility, reliability and quality for flat-bottom holes. Machining a flat hole traditionally required the use of an end mill and a drill. The ADF enables one-step drilling thereby simplifying machining time and tool management. The drill’s balanced point form improves precision and minimizes the shifting of hole position. Its sharp cutting edge results in low cutting force to minimize burrs even in thin plates. With a wide chip room geometry, trouble-free chip evacuation can be achieved. Furthermore, with the addition of OSG’s new proprietary EgiAs coating, tool life can be prolonged with excellent heat and wear resistance.

The ADF is engineered for a wide variety of drilling applications including inclined surfaces, curved surfaces, counterboring, eccentric holes, thin plates, etc. It is suitable for common materials such as carbon steel, alloy steel, hardened steel (up to 35 HRC) and cast iron. Standard types are available in diameters from 2 to 20 mm; long types are available in diameters from 3 to 20 mm).

Current Situation

David Whitmire, OSG district manager, has been covering a sales territory in Texas and Oklahoma for 9 years. He has witnessed both the best and worst days of the energy industry. Since the price of oil per barrel has recently reached record lows, our economy and oil field manufacturers have been severely affected. An increasing number of layoffs and downsizing at companies has occurred in the area. During this down time, some oil field manufacturers started to do their homework by reconsidering their machining processes as an avenue to cut costs. This has opened up some new opportunities for OSG in David’s territory.

One of David’s customers is a large pump housing manufacturer in the oil field industry. During the industry slowdown, the company wanted to be proactive, so they invited OSG and a local distributor to host a tap trouble shooting seminar. During the seminar, David showed them the OSG EXOTAP® A-Tap® and EXOPRO® Mega Muscle® drill videos. These videos drew a lot of attention as they showed A-Tap® and Mega Muscle® products surpassing speeds and feeds of competitors’ tools. This company produces 50 to 60 parts after spending over 625 hours machining per month. David decided to perform tool testing with his local distributor to help the company improve productivity and cut costs.

Tool Testing/Solutions

Material: 4140 Modified Alloy Steel

Results

Test 1 demonstrated a significant advantage of the A-Tap®. Even if it ran at the same speeds and feeds with the competitor’s tap, the A-Tap® was able to produce 25% to 40% more pump housings and to reduce costs by $22 per tool versus the competitor’s tap.

Tests 2, 3, 4 and 5 showed that OSG’s taps and drills ran at faster speeds than the competitors’ tools, and the A-Tap®, VXL Tap and Mega Muscle® products were able to reduce the cycle time by 23 minutes. In addition, the A-Tap® and Mega Muscle® machined 5 times more parts than the competitors’ tools did.

Tests 6 and 7 have not been completed, but David is confident that the WDO® drills and PXD drills will reduce the cycle times even more. By using OSG’s taps and drills in their operation, David predicts that the company will be able to reduce at least 21 hours of machining time per month!

What are the common issues you encounter while machining stainless steels and titanium alloys? You name it and OSG’s new EXOCARB® WDO-SUS drills will tackle it!

The WDO-SUS drills are specifically developed to combat work hardening, elongated chips, low thermal conductivity and welding on the tool. Watch the video below to learn more about the premium features of the WDO-SUS drills including the newly designed MEGA COOLER™ coolant holes.

One of our very own, Tim Holmer, will be hosting a presentation at AeroDef on April 22, 2015 titled “Composite Drilling—In Slow Motion.” AeroDef is the aerospace industry’s most acclaimed manufacturing event, featuring the leaders in commercial and defense aerospace manufacturing.

“Composite Drilling—In Slow Motion” is an experiment using high-speed video to show the effects of several drilling geometries in a variety of structural composites.  Attendees will learn about the challenges of drilling composites and the effects on hole quality. Common issues such as uncut fibers and delamination can be seen in a new perspective with the video visual aid, and tips on how best to avoid them will be explained. The information provided will help assist in proper selection of drill geometry for specific types of composites.

Tim has been providing customer support for various industries as an Applications Engineer for two and a half years. Before joining OSG, he graduated from Wright State University with a Mechanical Engineering degree.

When tapping, drilling, and milling heat resistant super alloys like Inconel 718, you need tools that can take the heat. OSG provides a total solution tooling trifecta for these tough machining applications.  With the rigid substrates, tailored geometries, and advanced coatings on our EXOPRO^® WHR-Ni Taps, EXOPRO^® WHO-Ni Drills, and EXOPRO^® UVX-Ni End Mills, you can tap, drill, and mill without the worry of rapid wear or extreme breakage.

Check out these tools at work:

The EXOPRO^® WHO-Ni drill series from OSG can take the heat when processing Nickel Alloy, Inconel 718 and other hardened steels.

These high performance drills incorporate OSG’s exclusive WXS nano-coating, which has been developed specifically for high heat applications. Internal coolant holes offer further heat resistance and chip evacuation, while a slow helix angle provides ultimate rigidity with minimal wear even after hundreds of holes.