Special Metals

[rake60]

The "Tiny" topic has lead to some discussion on special metals.
Would there be any interest in a caregory of just that?
How do you cut stainless? What's give you the best finish on brass?
We're all here to learn.

 

[ed miles]

Most of us root through the goody bin with the aim of finding something that is the closest size to what we need. Some education would help us all. For me, I started out with HS tool bits and played with hand ground shapes till one worked. Carbide inserts are also now a mystery as to which one to use with which material. Do we have anyone out there that is able to advise the home shop guy on a budget which insert is more versatile than another for general use in turning and boring.

Ed

 

[tattoomike68]

I like to use a TPU 322 insert. (322 is the size used at work, they can be had smaller)

Its good to have some C2 carbide for cast iron and some C6 TiN coated for hard steel, flame and plasma cuts.

A home shop machinist can make inserts last a very long time. when they dull a touch to a grean wheel and a little diamond hone work and you can sharpen them a few times.

 

[rake60]

For roughing I still use a lot of old grade 370 brazed on bits.
For finishing I use 3/8" shank turning tools that use TCMT21.51 inserts.
The insert that works best for me is the Kenametal KT315

I bought 6 pieces 4 months ago and I've destroyed only two of them.

Your right Mike. When your paying for them they do last a lot longer than
when your just signing them out of the tool crib.

 

[tattoomike68]

Your right Mike. When your paying for them they do last a lot longer than
when your just signing them out of the tool crib.

Boy howdy!

Kenametal inserts cost more but when I was working doing some long tough cuts I found I got 2 to 3 times the life from them over the cheapo non TiN coated inserts.

 

[rake60]

Well they run around $6 each retail.
I get them from an eBay store $3.80 each at:
eBay Store
The first time I was a little surprised to see they were Kennametal at that
price. There's no guarantee they will be the next time. The seller doesn't
state the manufacture.

 

[tattoomike68]

That e bay link is a good deal.

At one shop I worked at they had a 2" endmill that used the same inserts as our turning tools. that thing did a good job as a face mill or for side milling. That way we could use used inserts that the long flat side that never gets used.

Like this.. but a cheaper link

Its handy to have tooling that uses the same inserts on both lathe and mill.

 

[Hal]

123 people have viewed this polling post and only 9 have voted...

Not a strong turnout :shock:

Hal

 

[rake60]

That's why I asked before starting another category Hal
If there's no enough interest there's no point.

 

[wareagle]

123 people have viewed this polling post and only 9 have voted...

Not a strong turnout :shock:

Hal

This is a bummer! Out of everything I do in the shop, the biggest issue I face is trying to figure out what the best material is for a particular application. The second biggest issue is set ups.

I have a copy of Machinery's Handbook, and can dig the information out, but it would be nice to have some other opinions as to what works and what doesn't. I am sure others out there have the same issues.

 

[1Kenny]

I would like to know more about metals in use on small engines. Most of the time what is on hand is what I use, but it is ideal to know what not to use for a part. A good example was not to use brass or bronze for a crank wheel. I made the first one out of yellow brass and now I know why not to use it for that part. It will let the crank pin flex. Steel was the right metal.

 

[rake60]

OK guys we'll try it and see if it works.
If there is no interest we'll kill it.