Carbide tipped saw - cutting stainless

[RHiSC]

I've been using an Ozito cold cut saw with the supplied TCT blade to cut square mild steel tube with great quality repeatable results. I just recently started to cut some 304 stainless tube and after each cut the results got worse and worse. After 5 cuts it seems the blade is blunt and will barely cut...

Im only using light pressure to make the cuts and plenty of lubricant.

Replacement blades from Ozito cost about $140 so they must be half decent. Whats going on? anyone care to comment?

[Dave J]

I am not familiar with that type of saw or blade.But I know stainless work hardens, maybe you are trying to cut it to slow?
Dave

[RHiSC]

well the machines no load speed is 1300rpm... from what i understand, this is common for this type of machine.

[Dave J]

I was only thinking you may not be pushing it through quick enough as you said 'Im only using light pressure to make the cuts and plenty of lubricant.'
Dave

[RHiSC]

well it seems to have a lot of trouble making the inital cut because it is a round tube. once it is through, it seems to cut ok, until it gets to the end where it has trouble again. im pretty sure the blade is stuffed now though.

i was cutting 12mm thick mild steel bar like butter before this...

[Kody]

Check the tips of the blade for damage. If the tips are not so much as chipped as they are blunted , you can hand hone these back to a sharp edge. Get a diamond hone like the one here, (http://www.justtools.com.au/prod2464.htm)http://www.kingofknives.com/Cutlery/Brands/EZELAP/Ezelap-Diamond-Sharper-3-pack.html
The red one is the one you need but you can also use the light blue one for extra fine finish on the carbide teeth. If you are able to save the blades with these hones it will save you a small fortune. When using the hone/s keep dipping it into kerosene or diesel fuel to clean the hone and also lubricate it. The diamond hone really flies into the carbide but you do have full control on what you are doing. Apply the same number of strokes to each tip and it should work a treat.
Stainless steel is weird stuff. It is both soft and tough at the same time. It machines better at a slower speed than what you would choose for mild steel. If you are able to slow the saw down I am sure it would cut much better. However, slowing the saw sounds like an impossible thing to do. If you apply more pressure to the blade, you will overload the teeth and they will chip or break off. I am certain you will find the excess speed to be the main problem.

Kody

[radish]

Hate to say it, but the blade is rooted, go buy a new one, or, try and get that re-sharpened by a professional, try doing it your self and you'll still go buy a new one.

Stainless steel work hardens as it heats up, you going real easy on it, allowed the stainless to get as hard, or harder, than the tips on the blade.
Lesson learnt hear I hope, do not cut stainless with such a weapon, unless you got a big bank acount for new blades.

You want to cut stainless fast, then use a chop saw, make sure you even use the correct blade for stainless as well, end of story.

regards radish :D

[chips63]

I've been using an Ozito cold cut saw with the supplied TCT blade to cut square mild steel tube with great quality repeatable results. I just recently started to cut some 304 stainless tube and after each cut the results got worse and worse. After 5 cuts it seems the blade is blunt and will barely cut...

Im only using light pressure to make the cuts and plenty of lubricant.

Replacement blades from Ozito cost about $140 so they must be half decent. Whats going on? anyone care to comment?

I know when I ordered my cold saw they asked if I was intending to cut Hi Tensile or Stainless Steel to buy a Cobalt saw blade for this purpose.

The RPM is a bit of a worry, mine only runs at 40/80 RPM so we might be talking about two different types of cold saws !

[brisbanefitter]

I have not heard of a cold cut saw running that fast either, im not familiar with what type of saw it is.
only cold saws I have come across are the brobo kind which run at considerably lower speed, for a brobo either 21/42 rpm or 42/85 rpm on 3 phase models a 42rpm single phase.
Other similair cold saws of different brands pretty well run around the same speeds.
They use plenty of coolant running onto the blade, and a cobalt blade is recommended for cutting stainless and other high tensile materials.
I would go see a saw doctor or sharpening service like peacock saw we have up here in Brisbane and get their opinion on what type of blade to use in this machine.
You might even get a blade that can cut all your materials.

[DJ’s Timber]

The RPM is a bit of a worry, mine only runs at 40/80 RPM so we might be talking about two different types of cold saws !


I have not heard of a cold cut saw running that fast either, im not familiar with what type of saw it is.
only cold saws I have come across are the brobo kind which run at considerably lower speed, for a brobo either 21/42 rpm or 42/85 rpm on 3 phase models a 42rpm single phase.


Think you'll find that RHiSC is talking about is one of these (http://www.ozito.com.au/productinfo.aspx?prodid=OZCCS1800WA), completely different to the Brobo type

[hughie]

Way too fast thats the problem. Cold saws that are used to cut Stainless run around 200rpm or less. Also its best to use a fine toothed saw if your going through thin sections.