Machining Tips and Techniques for Working with M35 Steel

As a High-Speed Tool Steel, the M-35 variety is useful in almost every form and shape, ranging from square bar, plate, round bar, flat bar, wire, and sheets. But to make the most of this steel variety, it is important to understand the properties of the steel. It is equally important to have some machining tips and tricks up your sleeves.

Understanding M35

As a medium alloyed HSS tool steel, the M35 is also called HSS-E or HDSE. Its properties are somewhat similar to that of the M2 tool steel variety. However, it has 5% cobalt. The addition of cobalt makes the M35 tool resistant to heat. Also, it allows the steel to perform cutting jobs more precisely. This is why this steel is often utilized while manufacturing saws, hobs, shaper cutters, taps, broaches, reamers, millings, and the like.

Here are some tips to make the most from cobalt-based tool steels like M-35.

Feeds and Cutting Speeds

Mechanics often prefer slow speed for cutting, as well as low feeds. This helps minimize the generation of heat. It also helps to minimize tool wear. Ideally, you can start by considering a cutting speed of 80-100 fpm (feet per minute). The feed rate can be 0.002-0.004 IPR (inches per revolution). You can, however, adjust the recommended rates as you need. This would depend on specific applications as well as the tooling that you use.

Chip control

Often, M35 steels generate string-like long chips. This is likely to clog your work piece, as well as the tool. This is why it is important to use a chip deflector or at least a chip breaker. This would keep the longer chips from getting wound around the tool. Clean the work piece thoroughly.

Coolants

For better outcomes, you can consider using a high-pressure variety of coolants. For example, the use of cutting oil or a water-soluble cooler can keep both the work piece and your tools in a temperature-moderated way. However, ensure that the coolant gets directed to the zone of cutting. This eases the procedure of heat removal.

Work Holding

You can keep the work piece in the machine and avoid unnecessary chatter and vibrations. Too much vibration can make your tool chip break inside the work piece.

Finishing

One thing about M35 tool steel is that the engineers often have a tough time going through its work pieces with a smooth finish. This means that as an engineer, you might need to pursue various polishing or grinding steps to get the finishing that you desire.

Know about Annealing

Generally, the M35 suppliers deliver their metals in a machinable and annealed state. However, re-annealing could be necessary in case the metal is forged, hot-worked, or hardened. This is where your tool supplier can be of some help.

About Hardening

You can pre-heat this tool steel to 450-500°C. Later, you can increase the heat up to 820-880°C and finally to 1050-1250°C. Pre-heating also improves its machinability.

Tempering

It is necessary to temper right after quenching. However, for M35 steel, experts recommend triple tempering.

Some Extra Tips

To can get better results by:

• Take lighter cuts and avoid generating unnecessary heat.

• Break the cut up on multiple passes while machining a bigger work piece.

Hope this helps you get the best from your tool steel.