Weldon Shank End Mill

Do you consider using a Weldon flat on the shank of a cutting tool to be outdated? The situation may not be as straightforward as you believe. Let us first define what a Weldon flat is. The Weldon flat is a flat region on the shank of a tool. When inserted into a Toolholder, the flat on the shank is secured by set screws within the holder’s body. Using this flat, a set screw holds the tool securely and prevents rotation during milling. Although Weldon flat tools are mainly used for milling, they may also be utilized for other applications.

Who came up with the Weldon shank?

Carl A. Bergstrom founded the Weldon Tool Co. in Cleveland in the winter of 1918. He created a new type of endmill with a 30° helical flute while working in his business atop the Blackstone Building.

What is the shank of a milling cutter?

The diameter of a shank is the width of the shank, which is the end of the tool held by the tool holder that is not cutting. This dimension is essential when selecting a tool to ensure that the shank is the appropriate size for the holder.

What is an end mill flat?

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Flat-end mills are used for grinding operations, cutting 2D and 3D forms with flat sides, such as engravings and circuit boards. These carbide end mills may be used to create a square edge in metal, wood, wax, and plastic.

What are the many kinds of end mills?

The most popular type of milling cutters is known as end mills. A large selection of lengths, diameters, and kinds of end mills are available for purchase.

For most common milling tasks, a square end mill is the tool of choice. It produces a pointed edge at the bottom of pockets and slots.

There is a choice between the center and non-center cutting when it comes to end mills. The name of these end mills gives away the fact that they feature cutting edges not only on the cutter’s end face but also on the sides. For plunge milling, center-cutting end mills are an absolute need.

End mills with no cutting edge in the middle can only be used for side milling since their cutting edges are only on the sides. A little hole in the middle of each of these instruments is how they are distinguished.

Roughing end mills include serrations in their teeth that allow for removing large amounts of material in a short amount of time while minimizing vibration. The serrations result in a harsh finish and create a lot of little pieces.

Ball end mills leave behind a radius at the bottom of slots and pockets that they cut. Some of the uses for ball end mills include pocketing, shallow slotting, contour milling, and contour milling.

Square Endmills. Square Endmills have a profile angle of 90 degrees. They are utilized for general milling.

Weldon Endmills. Weldon Shank Endmills are manufactured with a Weldon flat to avoid slippage.

Ball Endmills. Ball Endmills (Ball Nose) is used to mill curved surfaces and feature a circular cutting surface.

End Mill Materials

End mills can be fabricated using cobalt steel alloys, also known as high-speed steel (HSS), or tungsten carbide embedded in a cobalt lattice. Both materials are used in production (shortened to “carbide”).

High-Speed Steel, often known as HSS, offers superior wear resistance at a lower cost than end mills made of cobalt or carbide. When milling ferrous and nonferrous materials for general purposes, HSS is the material of choice. Even though they are often more affordable, end mills made of HSS do not offer the same advantages in terms of tool life or speed as end mills made of cobalt or carbide.

Cobalt is an M42 tool steel with an 8% cobalt concentration, and its name comes from the element. Cobalt is more costly than HSS but offers superior wear resistance and hardness (M7). Both the metal removal and finish rate are superior to those achieved with HSS because the tool may operate 10 percent quicker.

Solid Carbide:  Carbide is a material that is far tougher, more rigid, and more resistant to wear than HSS. On the other hand, carbide is a brittle material that cracks more quickly than it wears. The majority of carbide’s uses are in the realm of finishing. Carbide tools are ideally suited for use in machine shops that operate relatively new milling equipment or machines with very little spindle wear. When working with carbide tools, it is essential to maintain rigidity. Carbide end mills may come at a higher cost than cobalt end mills, but they can also operate at two and a half times quicker rates than HSS end mills.

Both the material that will be cut and the maximum spindle speed of the machine are reasons that should be studied when selecting the tool material. It’s possible that more compact milling machines don’t have the horsepower necessary to attain the spindle speeds required for carbide end mills.

Coatings for the End Mill

The application of coatings to the surface of the tool will increase its surface hardness. Because of this, the tool life will be extended, and the cutting speed will increase.

Standard coatings include Titanium Nitride (TiN), Titanium Carbonitride (TiCN), and Aluminum Titanium Nitride (AlTiN).

Coatings made of titanium nitride (TiN) have a long service life and may be applied on alloy steel, aluminum, or plastic.

Extra-life TiCN (titanium carbonitride) coating offers superior wear resistance than TiN coating, making it an excellent choice for difficult-to-machine materials like ductile cast iron, stainless steel, aluminum, and plastic. TiCN coating is also more corrosion resistant than TiN coating. It has a bluish-gray hue.

The Super-life AlTiN (aluminum titanium nitride) coating is the most incredible option for very high feeds and speeds, and it also has a very long service life. Applications requiring elevated temperatures. Cast iron, stainless steel, nickel-based alloys, and titanium may be milled using this tool. Not for use on aluminum. The color is a bluish-purple gray.

The decision to employ coated end mills involves weighing the costs against the potential benefits. If the advantages of your machining

Buy end mills that already have a coating on them so you can benefit more fully from the enhanced performance offered by a premium coating.

Why use an instrument with a Weldon Flat?

Pullout” may be an issue when machining titanium and other hard metals due to the tremendous pressures required. Pull out is the propensity of a cutting tool to loosen from its holding and entirely twist out progressively. When utilizing an endmill with a high helix angle (more than 50°), the material contacts the helix and generates an axial force that attempts to pull the tool from its holder. The greater the helix angle, the greater the axial force generated, and the greater the likelihood of withdrawal.

Weldon flat holders can be advantageous during rough machining and the removal of significant quantities of material. In the aerospace industry, while machining components such as pricey wing spars, tool withdrawal can occur, which can be both highly expensive and quite harmful to the machined item. Titanium demands an aggressive depth of cut at relatively moderate spindle speeds, and Weldon Flat holders are suitable for the kinds of applications that include cutting materials like titanium. The proper machining settings provide significant torque forces on the cutter.

However, there are several drawbacks associated with using Weldon Flat tools. Endmill holders designed in the Weldon type move the cutter away from the holder’s center, resulting in runout and significantly shortening the tool’s life. The tool’s balance, or lack thereof, can be difficult. As a result of the fact that many high-end Machine tool makers specify that their machines can only accept “balanced tooling,” it is essential that the Weldon Flat Toolholders be precisely balanced before they are used. When applied to many different applications, employing Weldon flat tooling makes it impossible to get a run out of less than 0.010 millimeters.

Weldon Flat holders and shank tools with flats are still functional components in today’s sophisticated machine shops. However, businesses will be required to acquire a wide variety of tool holders depending on the application and the material that will be cut. Some tool holder manufacturers have created combination tool adaptors (hydraulic and shrink fit versions) for Weldon flats that give anti-pullout qualities to manage this wide variety of applications. These adaptors may be used with Weldon flats. These combo tool holders can be appropriately balanced while maintaining a low runout. One of the reasons why flats on shank tools are still in demand is because combination holders offer a solution to businesses who wish to employ Weldon flat tooling. This is one of the reasons why combination holders exist.

To get superior machining and stiffness, it is essential to identify the shank that will serve your purposes in the best possible manner. In most cases, selecting the diameter one size larger than necessary will result in increased stiffness while simultaneously reducing deflection and chatter. Because the designs of shanks are geared toward purposes, selecting the most appropriate shank is crucial because your collet will hold the tool. Standard straight shanks, single Weldon flats, double Weldon flats, complete flats, and shortened neck shanks.

SINGLE WELDON

• increases the amount of torque that can be applied
• reduces the amount of tool slippage and pull out
• acts as a reference for the correct amount of tool projection length

DOUBLE WELDON

• increases the amount of torque that may be applied
• reduces the amount of tool slippage and pull out
• stabilizes big diameter tooling

FULL FLAT

• Full flat for tooling that can be changed quickly
• enables variable degrees of projection
• allows the use of the same tool at both regular and extended lengths

REDUCED NECK

• Ideal for applications requiring extended reach and deep pocketing
• Improved core stiffness because of the lower flute length
• Relatively minimal tool deflection for high-finish, close-tolerance machining

STRAIGHT SHANK

• for use in shrink fit collets to decrease tool runout
• for high-performance machining applications
• increased tool concentricity
• often found on carbide tooling
• for high-performance machining applications

WELDON FLAT

The end mill is maintained in place by the Weldon flats, a cantilevered shaft supported by screws. It prevents the end mill from turning. Weldon flats are measured from the junction of the neck and the shank, and they are based on a high-speed tool standard called NAS 986, which ranges in diameter from.125 inches to three inches. Currently, no industry standard applies to carbide. Utilizing a flat has several benefits as well as drawbacks, including the following:

set screws prevent the tool from being pulled out of its socket; increases speeds and feeds

• The set screws keep the tool from sliding and add torque to the equation.
• Set screws force the tool against the opposite side of the holder, which guarantees that there will be some runout. Hand-ground flats reduce the performance of the device.

Final Thoughts

Weldon Shank Endmills are manufactured with a Weldon flat to avoid slippage. The application of coatings to the surface of the tool will increase its surface hardness. Because of this, the tool life will be extended, and the cutting speed will increase. Additional coatings for the End Mill include Titanium Nitride (TiN), Titanium Carbonitride ( TiCN), and AlTiN. Weldon Flat holders can be advantageous during rough machining and removing significant quantities of material.

Endmill holders designed in the Weldon type move the cutter away from the holder’s center, resulting in runout. Combination holders offer a solution to businesses who wish to employ Weldon flat tooling. Weldon flats are based on a high-speed tool standard called NAS 986, which ranges in diameter from.125 inches to three inches. Utilizing a flat has several benefits and drawbacks, including increased speed and tool concentricity.