what's happening between blade and steel?

The pressure per mm is lower, so the abrasive particles have harder times grabbing into steel.

Many people don't understand grinders. Like all cutting tools, they work the best when they're sharp. Unlike most tools, a grinder sharpens it's self. One of the biggest mistakes people make, is not feeding fast enough. You NEED the wheel to break down in order to keep it sharp. If you notice you're cut off wheel is starting to taper (the sides are wearing), it means you're not pushing hard enough. If you're not pushing hard enough, the wheel will load up, and not clear it's self. If you turn the edge of your part upright, you're putting more pressure in a smaller area.

1. The wheel only cuts at the contact patch between the surface of the wheel and the material. Cutting vertically enables the blade to "contact" the entire width of the material while cutting flat only cuts (at least initially) at the small contact point.

1. When you cut horizontally, there's more area for the heat to diffuse into the bar than if you cut vertically and the reduced retained heat my also influence the cutting rate.

Norm

good explanation, thanx!

IOW, are you viewing the abrasive blade as a VERY fine saw blade loading up? I noticed the effect the OP cites, and it is *profound*! It's almost as if the saw stops dead, cutting-wise.

Also, does it make sense to spray a recirculating coolant while abrasively cutting?

I know it's sure that way with angle. If you put it in there square, it takes forever to cut the bottom leg. If you put it in there with the angle up, it takes much less time.

But now, I use a band saw, having chucked those obnoxious chop saws.

But I'd buy a cold saw in a second if I could get a deal.

Steve

Steve

Abrasive chop saws are really handy for small stuff (rod, wire) and tubing, esp. miserable stuff like stainless. Unless you are doing accurate work or specific types of machining, cold saws are not that practical. But, they are easy to fall in love with. :)

Hey Steve, why are cold saws not practical? Is it because of their initial cost? I am considering the purchase of something other than my current singular method for severing metal, that is, my abrasive saw.

thanks, Bob

Hey Steve, why are cold saws not practical? Is it because of their initial cost? I am considering the purchase of something other than my current singular method for severing metal, that is, my abrasive saw.

thanks, Bob

Maybe....

I've never done it on a hot saw. Hot saws tend to work best with small surface area cuts like tubing and angles. These materials are typically low carbon steels. The heat generated from cutting them has little effect on the steel, so I don't mess with trying to keep it cool.

A hot saw is basically the same as a surface grinder. I've used coolant on surfaces grinders to protect the steel from heat damage, and to prevent warping of thin parts. As far as I could tell, the coolant does nothing for the life of the grinding wheel.

Hey Steve, why are cold saws not practical? Is it because of their initial cost? I am considering the purchase of something other than my current singular method for severing metal, that is, my abrasive saw.

thanks, Bob

Not only is the initial cost high, but so are the blades. Granted, they will last a long time if properly cared for, but it's going to hurt when you have to buy a new one. The capacity of a cold saw is limited compared to the capacity of a good band saw too.

I watched a guy melting a chunk of L steel ..cut the upright just fine..then took forever to cut the horizontal.

I shook my head at him when he started to load the part again. I turned the part over..so it was "^" in profile..and he cut it in about

I keep an assortment of angles, wedges and so forth on both the chop saw and the band saws, so I can angle chunks of steel to present the minimum surface area to blade and bands.

Lots of guys try to cut a flat bar either upright, or flat. Flat takes forever..upright it may bend if its thin..so I take that bar..and stick a round of something under it so its at a 10-30 degree in the vise, with the high side closest to the motor. This way..it doesnt hang a tooth on the sharp edge when you start..chips fall away..coolant flows down the plate to lube the as of yet uncut material and the blade is only cutting a thin but well supported width of the metal

_____>

]//o[

very poor asci..the material is only a bit higher than flat

I do the same with hex stock, a v block holds it with a sharp corner straight up, etc etc

Shrug

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"