Category: Carbide Drills

Controlling Chips at 3×D & 5×D: Drilling with the Inovatools 752 and 753 Coolant-Fed Drills

4/21/2026

Two-flute 140° notched point drills stabilize entry, control chip evacuation,
and maintain consistent hole quality when drilling steels, stainless steels, and cast iron.

Controlling Chips at 3×D & 5×D Drilling with the Inovatools 752 and 753 Coolant-Fed Drills Fullerton Tool

Drilling beyond standard jobber length increases sensitivity to thrust forces, chip evacuation, and thermal stability. The Inovatools 752 and 753 coolant-through drills are designed to control those variables in production drilling of steels, stainless steels, and cast iron.

Both series use a two-flute carbide geometry with internal coolant delivery and a 140° notched point. The design intent is stable entry, controlled chip formation, and consistent hole geometry as drilling depth increases.

Series 752 – 3×D
Coolant-Through Drill

The Inovatools 752 series is engineered for drilling up to three times the tool diameter. The 140° notched point reduces axial thrust at entry and promotes centering, which improves positional accuracy and reduces drift at shallow to medium depths.

Internal coolant holes deliver coolant directly to the cutting edges. This supports continuous chip evacuation and limits heat accumulation along the cutting edges and flute walls. The VAROCON coating increases wear resistance while maintaining edge stability in ferrous materials.

Series 752 features

Drilling depth: 3×D
Diameter range: approximately 1.0 mm to 20.0 mm
Flutes: 2
Point geometry: 140° notched point
Coolant: internal coolant holes

This series is suited for applications where hole quality, repeatability, and tool life are required without extended reach.

Series 753 – 5×D
Coolant-Through Drill

The IInovatools 753 series extends the same core geometry to drilling depths of up to five times the tool diameter. As drilling depth increases, chip evacuation and thermal control become primary drivers of hole quality and tool life. The internal coolant delivery system is designed to maintain chip flow along the full flute length at these depths.

The two-flute geometry and notched point are optimized to manage cutting forces as engagement length increases. This supports consistent diameter control and surface finish in deeper holes without reliance on frequent peck cycles.

Series 753 technical scope

Drilling depth: 5×D
Diameter range: approximately 1.0 mm to 20.0 mm
Flutes: 2
Point geometry: 140° notched point
Coolant: internal coolant holes

This series is intended for deeper drilling operations where process stability and predictable results are required.

Chip Control and Hole Quality
Hole quality is directly influenced by how chips are formed, broken, and evacuated from the cutting zone. When chips are removed efficiently and heat is controlled at the cutting edges, the drill maintains size, straightness, and surface finish more consistently.

The combination of internal coolant delivery, notched point geometry, and controlled flute design in the 752 and 753 series addresses these mechanisms directly, resulting in stable drilling behavior across a range of ferrous materials.

Application Fit
The Inovatools 752 and 753 series are designed for CNC drilling applications requiring 3×D and 5×D depths with internal coolant. They are suited for shops machining steels, stainless steels, and cast iron where hole geometry, chip evacuation, and process stability must remain consistent over production runs.

Diameter selection, application matching, and process recommendations should be reviewed based on material, machine capability, and coolant delivery.

For assistance selecting the appropriate drill series or optimizing an existing drilling process, contact Browne Sales for application support and availability.

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Chip Formation: You're Not Cutting Chips, You're Separating Metal from Itself

8/14/2023

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by Bernard Martin

Contrary to popular terminology, metal is not “cut” as much as it is a “forced separation from itself.” To understand this, think of how molecules bond together. Molecules resemble our solar system with the nucleus represented by our Sun (or a carbon atom in the image) and the electrons represent by the various planets.

When one molecule “bonds” with another it is as if two solar systems’ planets became intertwined into each others orbits with both solar systems sharing certain planets and making the whole larger than the sum if it’s parts.

When we use a cutting tool we are inducing these bonds to break apart.

The “machinability” of a particular metal partially defines how easily the material separates from itself.

The basic mechanics of forming a chip are the same regardless of the base material. As the cutting tool engages the workpiece, the material directly ahead of the tool is sheared and deformed under tremendous pressure. The deformed material then seeks to relieve its stressed condition by fracturing and flowing into the space above the tool in the form of a chip.

The important difference is how the chip typically forms in various materials.

Regardless of the tool being used or the metal being cut, the chip forming process occurs by a mechanism called plastic deformation. This deformation can be visualized as shearing. That is when a metal is subjected to a load exceeding its elastic limit.

The crystals of the metal elongate through an action of slipping or shearing, which takes place within the crystals and between adjacent crystals.

Type 1: Discontinuous Chip

Cast Iron, Hard Brass and other materials that produce a Powdery chip.

“Discontinuous Chip - Discontinuous or segmented chips are produced when brittle metal such as cast iron and hard bronze are cut or when some ductile metals are cut under poor cutting conditions.

As the point of the cutting tool contacts the metal, some compression occurs, and the chip begins flowing along the chip-tool interface. As more stress is applied to brittle metal by the cutting action, the metal compresses until it reaches a point where rupture occurs and the chip separates from the unmachined portion.

This cycle is repeated indefinitely during the cutting operation, with the rupture of each segment occurring on the shear angle or plane. Generally, as a result of these successive ruptures, a poor surface is produced on the workpiece.”

Notice how the chips deform and begin to break up at a considerable distance in front of the cutting edge. Chip control is usually not a problem when machining these materials. Harder, more heat and wear resistant Carbide Grades can be used in these applications. Edge strength becomes less of a factor vs. machining Steel or Stainless or other materials that make long chips.

Type 1 Discontinuous Chipping materials are where most of our competitors have focused their attention.

Type 2: Continuous Chip

Medium to High carbon and alloy Steels – Long Chipping Materials

“Continuous Chip - Continuous chips are a continuous ribbon produced when the flow of metal next to the tool face is not greatly restricted by a built-up edge or friction at the chip tool interface. The continuous ribbon chip is considered ideal for efficient cutting action because it results in better finishes. Unlike the Type 1 chip, fractures or ruptures do not occur here, because of the ductile nature of the metal.”

Carbon and Alloy Steels such as 1030, 1035, 1045, 1144, 4130, 4140, 4340 contain at least .3% carbon that allows them to be hardened by heating and quenching. They produce long continuous chips.

When machining these metals with Carbide Inserts the material in front of the cutting edge deforms resulting in high temperatures which softens the metal and consequently lowers it's strength and hardness making it easier to machine.

The chips weaken and begin to break in front the cutting edge; the tool acts much in the same way that a wedge does when splitting wood. In some cases, air, oil or coolant quenches the hot chips, hardening them and making them brittle and easier to break.

The chips produced when cutting these metals contact the face of the tool behind the cutting edge creating a zone of high heat that can result in cratering. Coatings usually eliminate this problem.

Type 2: Continuous chip materials are the other area where many of our competitors have focused their attention.

Type 3: Sheared Chips

Low carbon Steels, Stainless Steels, Nickel Alloys, Titanium, Copper, Aluminum and other soft, “gummy’ Materials.

Sheared Chips or as some refer to it “Continuous Chip with a Built-up Edge (BUE). The metal ahead of the cutting tool is compressed and forms a chip which begins to flow along the chip-tool interface.

As a result of the high temperature, the high pressure, and the high frictional resistance against the flow of the chip along the chip-tool interface, small particles of metal begin adhering to the edge of the cutting tool while the chip shears away.

As the cutting process continues, more particles adhere to the cutting tool and a larger build-up results, which affects the cutting action. The built-up edge increases in size and becomes more unstable. Eventually a point is reached where fragments are torn off. Portions of these fragments break off and stick to both the chip and the workpiece.

The build-up and breakdown of the built-up edge occur rapidly during a cutting action and cover the machined surface with a multitude of built-up fragments. These fragments adhere to and score the machined surface, resulting in a poor surface finish.

These metals readily deform in front of the cutting edge and have to be "sheared" by the tool. What the above paragraph doesn’t tell you is that these materials require tools with sharper cutting edges than those used for machining cast Iron or higher carbon content Steels. The chips tend to compress onto the face of the tool which can result in built-up edge.

The chips formed when cutting these metals are thicker than those produced by Medium Carbon or Alloy Steels at the same Feed Rates and Depths of Cut. These thicker chips are stronger and harder to break. Destiny Tool, through a combination of rake face geometry, carbide substrate and concentricity tolerance is able to enable the chip to more readily "separate from itself" which not only improves MRR, but also reduced heat into the end mill and thereby extends tool life as the feed rate increases.

High strength metals such as Stainless Steel, Nickel Alloys and Titanium generate high heat and high cutting pressures in the area of the cutting edge. This results in reduced tool life compared to easier to machine materials.

This article was originally written in 2001
Portions of this have been edited from http://www.manufacturingcenter.com/tooling/archives/0101/0101bk.asp
Plastic Deformation image by Jutka Czirok, Design Technology and ICT Teacher
Special thanks to Charles Colerich, who created these drawings for me in 1994.

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Drilling Ferrous vs. Non-Ferrous Metals

7/19/2022

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This article is courtesy of Regal Cutting Tools.

Different tool engineering, composition, and design affect the way they perform and which workpieces they will cut most effectively. Several factors determine which drill bits work best on various steels and alloys, copper, zinc, aluminum, tin, etc., owing to the properties of ferrous vs. nonferrous metals.

Properties of Ferrous and Non-Ferrous Metals

Ferrous Metals

Ferrous metals, of course, are those that contain iron. These include stainless, carbon, and alloy steel, and cast and wrought iron. Ferrous metals generally possess more tensile strength than their non-iron-based counterparts. That makes them ideal for use in building materials, structural and ornamental designs, and heavy industrial products such as shipping containers, tools, and appliances. Tool manufacturers must consider hardness and strength when designing and engineering drills made for cutting ferrous metals.

Non-ferrous Metals

Non-ferrous metals - especially copper, lead, zinc, and tin also occupy important niches in the construction and manufacturing industries. Because they contain no iron, these metals are valued for their use in applications where they come into contact with moisture that would rust ferrous metals. They also are malleable, ductile, and easily manipulated into various shapes for components, housings, etc. They are non-magnetic, making them quite useful in electronic components.

Hardness is the primary consideration when choosing a drill to cut metal.

Drills incorporate various design elements in order to cope with these different challenges

Points and Angles

Drill bit points can be altered to provide more precise hole-starting, centering, and quality, as well as conduciveness to varying feeds and speeds. The standard 118-degree point is used because it offers a “good enough” fit for most applications.

Standard points can be used for most “softer” steels and non-ferrous metals. Standard 135-degree split-point drills can cut these materials, as well as harder steel alloys. In these harder materials, the split-point offers the advantage of working at lower feed pressure and centering of the hole with minimal walking. Learn more about how to find the right drill point angle for your application

Flutes

The grooves cut into drill bits (called flutes) serve two purposes:

To remove material sheared by the cutting edge from the inside of holes.
To allow coolant or oil to reach the cutting surface to cool the cutting edge.

As we might expect, the harder the material being drilled, the harder the tool must be to get the job done. Carbon steels are too soft for cutting metal; only high-speed steel (HSS), carbide-tipped, and solid carbide bits should be used in cutting metal, no matter how soft. HSS is common because of its low cost and ability to drill softer carbon steels as well as zinc, copper, aluminum, and other non-ferrous metals.

Alloying HSS with 5 to 8% cobalt adds “red” hardness which allows the tool to maintain the sharp cutting edge longer and allows for slightly faster speeds, making these drills suitable for working in heat-treated steel, cast iron, and even some titanium alloys.

For exponential increases in speed and wear resistance, nothing beats using a carbide tool. It withstands extremely high temperatures, resists wear, and maintains rigidity better that HSS. It costs much more, but is the only long term, high volume option when the work piece is stainless steel or alloyed steel. Carbide-tipped HSS saves some costs and is a viable option for nonferrous metals such as copper, bronze, and other materials that are highly abrasive.

Drills made of cobalt-alloy High Speed Steel (HSS-E) or even drill bits with a thin film coating are needed for stainless steel. These are more expensive than normal HSS drill bits, but they enable drilling in special steel without a high level of drill bit wear.

Thin film coated drill bits are high-speed steel drill bits (HSS) that have any of a variety of coating blends typically with a titanium base. TiN (Titanium Nitride), TiALN (Titanium Aluminum Nitride) and TiCN (Titanium Carbonitride) are examples of thin film coaing typically used on drill bits. They are very hard, and corrosion-resistant and reduce the co-efficient of friction allowing for better lubrication of the tool. They last much longer than regular HSS drill bits, and they are good for cutting through any metal, including metal sheeting.

Thin film coated drill bits have a surface that is harder than cobalt. However, because they are coated, they lose the coating protection at the cutting edge when they are re-sharpened and subsequent tool life will be reduced. Uncoated drill bits are made of cobalt or HSS steel, and they can be sharpened without any loss in performance or tool life.

The type of metal being drilled determines width, and shape of flutes. Harder ferrous materials can be cut only by stronger, harder bits operating at a slower feed rate when compared to non-ferrous materials.

Drills designed for harder materials tend to have a flutes with slower spiral as the chip material may not be very flexible. The slower spiral adds rigidity to the tool and additionally results in a lower rake angle at the cutting edge, providing edge strength while cutting these tougher materials. As a result, steel and iron chips are smaller and can be evacuated easily, using narrower flutes.

Softer, nonferrous metal can be drilled at faster speeds, as there is little danger of breaking the bit. The material comes off in ribbons and strings rather than chips.

This necessitates wider flutes designed with a higher spiral angle to prevent clogging and create a “pulling” action on the non-ferrous chips.

The higher spiral creates a higher rake angle at the cutting edge allowing the softer non-ferrous material to be sheared from the workpiece.

Construction

Ferrous vs. Non-Ferrous Metals

Understanding the characteristics of ferrous and non-ferrous metals, and what twist drill is ideal for each material is key to high quality production and extending tool life. If you are still unsure of exactly which drill is right for your job, contact a Browne & Co. Sales Rep and we would be happy to assist you.

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InovaTools - Supplied, Stocked and Supported!

10/5/2020

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Fullerton Tool Company now supplies, stocks, and supports InovaTools' products!

Their strategic partnership with InovaTools allows Fullterton to expand thier product offering by selling, stocking, and supporting Inovatools' coolant fed, deep hole drills, micro drills, modular tools, diamond coated end mills, and die & mold end mills.

Fullerton is Now Offering InovaTools:

Coolant Fed Drills
Deep Hole Drills
Micro Drills
Modular Tools
Diamond Coated End Mills
Die and Mold End Mills

Download our InovaTools Catalog for a full offering of available products sold by Fullerton or download the Tooling Portfolio for an overview of available InovaTools products

Inova Catalog

Inova Portfolio

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Enhanced Chip Evacuation With The AlumaDrill

9/19/2020

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Fullerton Tool's 1565 AlumaDrill is a master of enhanced chip evacuation in high speed drilling in titanium, graphite, brass & copper, high si aluminum, low si aluminum, composites, plastics, and wood. Its unique radial grinds allow self-centering and increases aggressiveness in softer materials.

1565 AlumaDrill Features:

Enhanced chip evacuation in high speed drilling applications
Unique radial grinds allow for self-centering and increases aggressiveness in softer materials
3 flute design
30 degree helix
130 degree high performance point
Standard tools are uncoated; coatings are available upon request

Start your search for an AlumaDrill with the button below:

Search AlumaDrills

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Controlling Chips at 3×D & 5×D: Drilling with the Inovatools 752 and 753 Coolant-Fed Drills

Series 752 – 3×D
Coolant-Through Drill

Series 753 – 5×D
Coolant-Through Drill

Chip Formation: You're Not Cutting Chips, You're Separating Metal from Itself

The “machinability” of a particular metal partially defines how easily the material separates from itself.

Type 1: Discontinuous Chip

Type 2: Continuous Chip

Type 3: Sheared Chips

Drilling Ferrous vs. Non-Ferrous Metals

Properties of Ferrous and Non-Ferrous Metals

Points and Angles

Flutes

Construction

Ferrous vs. Non-Ferrous Metals

InovaTools - Supplied, Stocked and Supported!

Enhanced Chip Evacuation With The AlumaDrill

Author

Archives

Categories

Controlling Chips at 3×D & 5×D: Drilling with the Inovatools 752 and 753 Coolant-Fed Drills

Series 752 – 3×DCoolant-Through Drill

Series 753 – 5×D Coolant-Through Drill

Chip Formation: You're Not Cutting Chips, You're Separating Metal from Itself

The “machinability” of a particular metal partially defines how easily the material separates from itself. ​

Type 1: Discontinuous Chip

Type 2: Continuous Chip

Type 3: Sheared Chips

Drilling Ferrous vs. Non-Ferrous Metals

Properties of Ferrous and Non-Ferrous Metals

Points and Angles

Flutes

Construction

Ferrous vs. Non-Ferrous Metals

InovaTools - Supplied, Stocked and Supported!

Enhanced Chip Evacuation With The AlumaDrill

Author

Archives

Categories

Series 752 – 3×D
Coolant-Through Drill

Series 753 – 5×D
Coolant-Through Drill

The “machinability” of a particular metal partially defines how easily the material separates from itself.