Speeds and feeds are the most important considerations to achieve the best results from cutting tools. Improper speeds and feeds often cause low production, poor quality, and damage to the tool. Speeds that are too high or feeds that are too light can lead to rapid wear and dulling of the cutter, reducing tool life.
Speed is measured in peripheral feet per minute. It is often referred to as cutting speed or surface speed. Feed is usually measured and stated in inches per minute (IPM). It takes into consideration the number of cutting teeth (or flutes), the feed per tooth (or cutting edges), and the revolutions per minute.
Coolant can dramatically affect the performance of cutting tools, which can
impact the cost of your operation. Consider these guidelines for using coolant:
Cutting fluids perform two basic functions in drilling, milling, and threading:
1. to reduce heat generated in cut;
2. to lubricate the tool.
Water-based coolant helps to cool the chip when it is sheared from the workpiece material.
PVD TiN (Physical Vapor Deposition Titanium Nitride) coatings are the primary general-purpose coating for end mills, but TiCN (Titanium Carbo-Nitride) and TiAlN (Titanium Aluminium Nitride) are becoming popular in use. Common questions for milling applications include when to use these advanced coatings, and at what speeds to run them.
TiCN is a harder coating than TiN and has good abrasion resistance. It is very good in milling applications for steels, stainless steels, and non-ferrous materials. End mills coated with TiCN should be operated at speeds up to 50% higher than uncoated end mills.
All cutting fluids have, to a greater or lesser extent, the potential to cause health issues for machine operators. These risks are based on the external (skin) or internal contact involved in machining work; including the touching of parts and tooling, being splashed by the fluid, having mist settle on the skin or via the inhalation of mist.
The key to minimising this risk is the full evaluation of the machining operation; this process starts with the selection of the most suitable cutting fluid.
While there are many factors that affect the life of a cutting fluid, such as dilution control, tramp oil, top up rates etc. the key to ensuring maximum sump life from any fresh fill is machine cleanliness.
Why Clean? During use, machine tool fluid systems become contaminated with tramp oil machining debris, hard water soaps etc. which can be found on the sides and bottoms of tanks. These deposits are ideal breeding grounds for both bacterial and fungal infections and eventually become “biomasses” that can shorten fluid life.