Straight Shank Series Metric Endmills

55-58 HRC Coated with TICN.
All centre cut - Made from 100% high grade carbide.

When selecting your desired size above, please note our endmills are measure as the shank size X the overall length of the endmill.
These cutters are made for us only and are one of our new ranges of exclusive products to LPR Toolmakers, give them a try and you won't be disappointed.

CL = CUTTING/FLUTE LENGTH

OAL = OVERALL LENGTH

SIZE = DIAMETER OF CUTTER4

4 Fluted -  2mm Shank x 50mm Long

Machining Material

Also, the material being machined must be understood. Since 1018 carbon steel and D2 tool steel don't have the same machining qualities, a different approach must be taken for each. Most end mills will perform just fine for the 1018 with any number of flutes. With harder materials, such as D2 (58 HRc), more flutes, lighter cuts and less speed must be used. The reason for more flutes is because of the lighter feed rates and the need to keep production levels high. Also, as the strength of an end mill increases due to a larger core which helps to decrease tool deflection, different approaches for stainless steels must be used because stainless materials tend to work harden if the feed rate is too low.

In aluminium with low silicon percentage (under 5 percent), the material can be a bit gummy leading to built-up edge so high speeds and feeds need to be used to keep the chips evacuating from the flutes. As you can see, the material being used is a dominant factor when deciding speed and feed for all applications. Another consideration is the helix angle of an end mill. It is generally accepted that a 30x angle is industry standard for sharpness and cutting edge strength. This is adequate for carbon steels, some tool steels or even light finishing passes in aluminium. However, when machining stainless steels, a sharper cutting edge needs to be employed as to lessen the work-hardening effects and promote a more free cutting action. This is where a 45x helix angle does well because there will still be some cutting edge strength along with the appropriate sharpness needed. This angle also is good for aluminium when engaging in a deeper slot or periphery cut.

When machining Inconel or other difficult-to-cut materials, a 60x helix needs to be employed. The shearing action is greater, but the tooth edge integrity becomes less. One might think that a weaker cutting edge could cause problems for these materials, but since the feed rates must be kept low, the cutting forces are low enough to maintain cutting edge integrity. Additionally, it might be considered that a sixty-degree angle would be even better for aluminium. That is not the case as the chip flow is not very good because of aluminium’s gummy properties and the fact that the end mill must be run at a high sfm to be effective in cutting aluminium. That combination of speed and the helix angle for this material does not allow for proper chip evacuation.

Considering Coatings

Now, a very important process that allows the carbide end mill to resist wear is the coating. Although solid carbide end mills perform better and last longer in most applications when compared with high-speed steel, heat is not carbide's friend. In the last decade, the technology to provide more heat- and wear-resistant coatings has promoted longer tool life and increased productivity. There are three major types of coatings that are being used today: TiN (titanium nitride), TiCN (titanium carbon nitride) and the increasingly popular TiAlN (titanium aluminium nitride) or AlTiN (aluminium titanium nitride)-the latter having more aluminium content. Other coatings exist, but they are usually offshoots of these three. All of these coatings provide a benefit, but that benefit can only be realized when dealing with specific applications and materials.

TiN-coated end mills should be run at close to uncoated speeds and feeds. The benefit here is much better wear and lubricant. TiCN is a great coating where slow feeds and speeds are used because of machine constraints. It's often the coating of choice for high-speed steel end mills, but in carbide you can run it at least 80 per cent faster speed against uncoated solid carbide end mills. The only downfall with TiCN is that it's more prone to failure under extreme heat; hence, it's use in slower feed and speed applications.