Cutting Steel at home?

[biosbill]

Hello,

Im sure this has come up many many times before, but I really am not sure....

Basically im just building up some rock sliders for the landrover (1973 SWB) trouble being; as these are reasonably structural they're made from hefty 4mm and 5mm plate...

My problem comes; everybody in their "workshop guides" and "how to's" just says; "then I made a template"...fine I can do that easy, cardboard, nice and neat, brilliant...

THEN... "then I just cut this from the steel plate I had laying around" ???? Ive bought the steel plate (and some 80x40x4mm box); I gave the metal suppliers some card templates and they cut some of the plate that they could with their enourmous press/guilotine, but they couldnt cut anything diagonal so they just cut the squares and given me them......

I was going to get the plate cut at work on their "donkey saw" ..chugs along all day and I could leave it over lunch, but they've been so busy I havent had chance...

Does everybody really have a plasma cutter to hand!?, or do they just use an angle grinder (as im planning too) Its just pretty slow, (thinking of using plasma cutting discs) do people just take their time and do it this way; I know its possible, just wondered if theres a "golden secret" of cutting that everybody uses!

Thanks,

biosbill

 

[malcolm]

I don't cut very much 6mm sheet. My method is to clamp the sheet so it can't fly around, cut 2/3 of the way through using a 1mm cutting disc on an angle grinder, then put the sheet in a vice and fatigue the 2 parts apart. From there clean to shape with a grinding disc.

Reason I don't cut all the way through is the discs can snag and wear out if they are exposed to an edge. The thin cutting discs are fairly quick.

 

[biosbill]

I don't cut very much 6mm sheet. My method is to clamp the sheet so it can't fly around, cut 2/3 of the way through using a 1mm cutting disc on an angle grinder, then put the sheet in a vice and fatigue the 2 parts apart. From there clean to shape with a grinding disc.

Reason I don't cut all the way through is the discs can snag and wear out if they are exposed to an edge. The thin cutting discs are fairly quick.

Ahhh very interesting! I did actualy make a cut about 15cm all the way through with a plasma disc, but due to the fact (as you say) it was going all the way through the steel it wore out very fast...although your method sounds really effective.

Thanks,

biosbill

 

[JayRS4]

Maybe, just maybe, there`s a local member that might help you out if they`ve got a plasma to hand, i would but it`d be a bit of a journey. Aren`t there any small local fab shops near you, or possibly a well equipt garage?

 

[Arsonista]

Use Smith & Arrow .8 cutting discs. Don't push too hard though, let the disc do the cutting. If you've still got a guard on your angle grinder, you can set it as a kind of 'depth gauge', to cut down on snagging. If it's not a very long cut, use a jig saw with a metal cutting blade and a bit of oil. Again, let the blade cut, don't push too hard, you'll just generate heat.

 

[peterd51]

Hi,

I cut some 6mm steel once and it took a while. The method I used then was to run a normal grinding disk down both sides to get a groove a couple of mm deep, then run a thin cutting disk down each side to get mostly through and fatigue off as Malcolm suggested.

The normal grinding disk doesn't go very deep but it does take the sides away and it stops the thin cutting disk wearing out too quickly. The hardest bit was flipping the sheet over each time to have a go at the other side.

Regards
Peter

 

[English Steve]

Don't have a plasma, so anything over 3mm thick that won't fit in the bandsaw gets cut with discs or oxy/acetylene. Or you could try a good old fashioned hacksaw - take a while but save you going to the gym.

 

[biosbill]

Hi again,

Cheers for all the advice....hadnt thought of the gas axe! Another good reason for me to think about getting one..plus they look damn cool!

Think ill have a go with the grinder and the "thinning" technique, then fatigue breaking it...

Thanks,

biosbill

 

[wyn]

I often use a 9" grinder for anything above 4'ish mm with a thin cutting disc 1.2mm or something like that.

I also cut up to 20mm thick with them and no problems. It does take a little while though and plenty of dust etc.

 

[Chipper]

Would a chop saw or TCT saw help? Got a Rage something-or-other sliding mitre saw, £99 from B&Q I think, twas as cheap as anywhere I found on the net. Just been munching 75mm x 12mm with no complaints. The clamps are dodgy but for DIY use and price, can't fault it.
Could be good for the box, but depends on size of plate as to whether that'd fit I guess.

In fact here 'tis in the back of my Lightweight-

edit - BB I see you're just across the way in the badlands If it's not too far for you yr welcome to pop over and chop stuff up of an evening.

 

[biosbill]

hi,

Thanks for the photo! Altohugh dont really think thats the machine for me, I cant realyl afford anything at the moment....although it probably would work just about for what I want.

Its probably only going to be used once or twice as I can get most plate cut else where or by the steel supplier, but just this time Ive run out of time and I dont want to spend a Saturday twiddling my thumbs due to not having cut it.

Will give it a go with the grinder as above I think, cheers for the pointers, esp going only half way through so as not to wear out the disc!

Biosbill

 

[Barney1973]

Just a quick pointer,wear a mask as the dust will do your lungs no good at all!

 

[biosbill]

Success!!

Just been out and cut and drilled one of the plates...I clamped it to the workmate with a piece of wood underneath..then just kept taking "runs" at it, taking a little bit more each time, until it started to go through in places, then I just took it off and finished it off with a hacksaw; straight through...quite easily actually!

Then I drilled the mounting holes, did think id need to use a pillar drill for plate that thick, but I did it all with out 24V battery drill! Was quite impressed actually...

Job for tomorrow is cut the other plate, which is now already drilled. Then get the whole lot bolted to the car, then grind everything to fit nicely and square, ready for weld when ive next got the welder here..

Thanks again,

biosbill

P.S thanks for the pointer about the mask; didnt know that grinding wasnt great on your lungs! Always wear goggles and gloves now, ear defenders if under the car too (couldn't hear for two days after a load of grinding under there ) Wont even spin the tool up without goggles now; had a brush implode on me and hit me 2cm above my left eye..still have the scar there now, was just about to pull the goggles down, but it was too late!

 

[rodofgod]

Hi All!


biosbill,

If the parts you need cutting are straight lengths, then the quickest and easiest way is by guillotine. It is quite easy to cut straight lines, diagonally on a guillotine,so I can't see why your steel supplier couldn't do this for you.

Most reasonably sized metal/fab shops have one!

Next method would be oxy-fuel cutting or plasma! This method would also allow you to cut radially, curves etc. and then trim back with a grinder to the final size.

For the box section, a chop saw is by far the easiest way for a hobbiest to cut this material.

Regards