Cutting steel plate with grinding disc
|Speedy Builder5||29/11/2010 17:40:21|
|2186 forum posts|
I don't like hacksawing thick steel plate, and have had success cutting with a large angle grinder cutting disc mounted in a bench mounted circular saw.
For safety, check saw rev/min and disc max speed and cutting suitability.
Wear breathing mask and full face visor protection.
Wear thick leather gloves.
Possibly ear defenders.
Cover all other machines with cloths, or preferably work outside.
If possible, use some sort of extraction system that is spark proof. You can buy spark arrester bins for cleaning out ashes etc from fires and connect to your extractor system.
I have cut MS, SS and gauge plate (without hardening it) quite successfully.
|1040 forum posts|
I use an Evolution Rage 185mm Circular Saw for cutting MS plate. I must admit I was very sceptical at first but these saws are amazing. Max cut in MS is 6 mm however I have cut 12mm plate in 2 passes with no problems, no sparks, no heating, the metal is cool to touch immediately after cutting, see http://www.evolutionpowertools.co.uk/uk/evolution_rage.html
|Peter G. Shaw||30/11/2010 11:34:57|
1232 forum posts
Interestingly, I have had some success with a B&D Skorpion fitted with a metal cutting blade. At any rate it's easier than hand sawing, and for someone with Menieres which has been brought on by the rocking motion when sawing, it's definitely better.
I've also used a 9" metal grinding disc on an angle grinder to cut up an old file.
Currently, awaiting trial, I have a 5" angle grinder complete with thinner metal cutting disks.
Peter G. Shaw
ps the Skorpion does produce a lot of vibration, and although I originally bought it for wood cutting, I eventually found the vibration too much to cope with. I now use a circular saw/chainsaw/bush saw as appropriate. The vibration is tolerable for metal.
|Nicholas Farr||30/11/2010 11:58:24|
2549 forum posts
Hi Peter, you can get 5/64 (2mm) cutting discs for your 9" angle grinder cut steel pretty reasonably, but don't go to the likes of B&Q as you'll pay more, better off going to local engineering suppliers, as the quality is better at a better price. I use 9" 7" 4.5" and 4" angle grinders myself, not necessarily in that order of course. You should always wear appropriate gear with these, i.e. ear defenders, visors, overalls, steel toe cap boots, gloves, idealy anti vibration gloves are best.
|Peter G. Shaw||30/11/2010 13:11:20|
1232 forum posts
Yes, I came across this problem with my son-in-law's angle grinder when I bought a box of 25 Bosch discs for what would have been peanuts compared to the B&Q individual prices.
My 9" angle grinder came from Aldi and has only been used perhaps five time in total. It does the job, but it's a bit big.
The 5" grinder came from Argos end of stock or what ever they call it, whilst it's discs are Arrow & Knight (??) bought via the internet. I know it works, but haven't yet had a chance to use it properly.
Agree about the safety aspects except for the boots - haven't got any.
Peter G. Shaw
|Nicholas Farr||30/11/2010 13:25:49|
2549 forum posts
Hi Peter, be very carefully then, because they'll cut through ordenary footware very easy and will keep going before you have time to stop. Position yourself as best you can so that if the disc does snatch i will be away from body area. I've seen nasty injuries with these, with people who don't think about which way they will pull out of your hands, and somtimes they can catch you out like that. I've been using such gear for 40 odd years and still get the odd snatch now and again. Mine are all 110V industrial jobbes.
Edited By Nicholas Farr on 30/11/2010 13:27:39
Edited By Nicholas Farr on 30/11/2010 13:28:01
|96 forum posts|
I have lived my youth in a farm and an industrial size agle grinder was used to free stubborn bolts and such as well as prepare plates for welding. I have used those all my life and I am careful and somewhat reserved any time I touch them.
I use metal cutting bandsaw to cut material for a lathe and milling machine. One of the best equipment I ever bought. Blades are very important. Cheap ones or too low pich for the work will shear of teeths in no time. Very little waste. Less noice. NO SPARKS. Can even slit.
Any grinder will produce sparks and that creates major prodedural problems inside any building.
|Roy Moss||30/11/2010 17:06:06|
|9 forum posts|
I use a power hacksaw, Meddings or Manchester types. Cuts straight and accurately, and HSS blades can handle tough materials. I got mine secondhand at local auctions, from £50 to £150 each. I get blades from model shows. Disc grinders are very good for cutting where you can't mount work on a machine, or an accurate cut is not important. You do need to rest or mount these power hacksaws on a solid floor; I tried to be clever and put them on wheeled trolleys, but moter power seemed to go more on making trolleys wobble than on cutting steel.
463 forum posts
I have a 20 year old ELU jig saw that i often use to cut steel plate up to 1/4" thick, and have cut ally up to 5/8" thick. I only use Bosch blades with the correct No. of TPI for the job. I find it also helps to give the blade a tiny squirt of weld anti-spatter wich stops the blades clogging particulary on ally.
|Gordon W||30/11/2010 17:41:17|
|2011 forum posts|
I use small A/G with thin blade for cutting- tool steel even, grinding disc for roughing lathe tools. Big 9" for cutting and grinding. Be very careful with these things, biggest danger is fire, sparks go a long way, ruined many a jumper, shirt, and overalls with large hole in middle, don't wear nylon, esp. socks. Only personal injury I know of was my near neighbour who badly damaged his hand and had to drive himself to hospital. He was up a ladder, with a 9" grinder, trying to cut cast iron gutter, whilst holding the ladder with one hand.
|188 forum posts|
Maybe my experience cutting steel might raise a laugh - I don't want to go into the Health and Safety lunacy (doesn't apply anyway in Romania), but not so long ago I needed some 3mm steel plate, so I went into town (Arad) to see what our local supplier had. He is usually excellent - I can buy all sorts of material which I would have no idea where to obtain in England (or Germany, where we used to live).
He had several sheets in stock, but they were 220cms x 120 cms - rather more than I wanted (or could carry in or on my car!), very heavy, and he had no means to cut it (I later found out that people were expected to buy the whole piece), but he agreed that if I could get it cut, I could buy half a sheet - he suggested I use what he called a 'Flex cutter'. (Angle-grinder to you or me).
To keep a long story short, I returned next day with a hand-held 2500W angle grinder fitted with a 25cm metal cutting disk, a pair of heavy welding gloves, and a pair of safety glasses, and gave them to the metal-man, expecting (hoping!) he would cut the metal. He looked surprised, gave me them back, and told me I had to do it myself. So I did - it only took about 10 minutes, and I had to say it was much easier than I expected but a bit nerve-racking and noisy. I don't really want to do it again, but I got my half-sheet of steel, cut with no distortion along the edge.
So now I have enough 3mm steel for no end of loco frames, manhole covers, etc.
On the serious side, I have done lots of cutting with small (15cm) metal cutting discs in an angle grinder, and it is possible to work quite accurately with them, leaving only minor finishing needed. Aside from my story above, I agree with the precautions, and fully endorse Gordon W's comments. I would also note that these disks are very thin - I have had occasions where the edge of the disk has chipped for some reason, and this has led to almost instant destruction of the disk, with bits flying far and wide. At the very least, the edge of the disk has 'shredded', and in those circumstances, I always scrap the disk, rather than take a chance - needless to say, safety glasses are essential.
Edited By Keith Wardill on 30/11/2010 18:58:02
|Stub Mandrel||30/11/2010 21:32:37|
4311 forum posts
I've used a hand held angle grinder to chop up 5mm sheet with no more damage than frayed nerves and some iron filings embedded in the conservatory windows =:-0
The same grinder (with a different blade) made short work of some surplus 'composite granite' worktop for a surface plate, although I got over enthusiastic as it was cutting so well and burnt it out on the last bit. It was worth teh £12 i paid for it just to see the smoke
I'm glad it's not just me. I have had some problems with the nerves in my right hand and five minutes with the scorpion turns it into a lump of dead meat for half an hour!
Edited By Stub Mandrel on 30/11/2010 21:36:16
|Ian S C||01/12/2010 09:48:43|
7468 forum posts
On one of the jobs I do, it is required that I cut bits out of some components that ar made of 2mm steel. I clamp a bit of angle iron along the line and use a thin cut off wheelin the 120mm angle grinder. The job needs a couple of strokes with a file to deburr it, finished. I'v used the same system on 1/4"/ 6mm OK.
Watched the apprentice at a local sheet metal works burst 2 disks in a row, and was going to do another when the boss intervened,. The lad was cutting stainless sheet metal, and got in too deep, and jambed the wheel. Ian S C
|John Stevenson||01/12/2010 10:16:23|
5068 forum posts
Those 1mm thick cutting wheels are awesome.
First time I used them I was trying to get an immersion heater out of a big, I mean big, it came on a lorry, water tank in stainless.
When built they had fitted the heater element with a loose nut inside, then welded a false base over it.
Now the element had gone the whole lot was just spinning.
Weighed the job up and cut the element out of the 2mm thick stainless tank in an 8" or so square.
Cut the nut off, made a new brass flange screwed to the bit of square plate so it wouldn't happen again and Tig welded the same bit of plate back into the same hole.
Whilst I was at it I also did the other three heaters so I wouldn't have to have the same hassle the next time.
The ones for the 9" grinders are also very good but thicker at 2mm, I bought one of the 9" grinders from Aldi as a backup for the old Bosch and I like it that much I use it all the while.
The new one has soft start and a handle that can spin 90 degrees making horizontal or vertical cuts a lot easier.
Few weeks ago I ordered a bar of 90mm black steel, it comes in 7 metre lengths so I asked the suppliers to cut it in half so it was manageable.
This is how it came <g>
|Peter G. Shaw||01/12/2010 10:40:38|
1232 forum posts
Sorry to read about your nerve problems. Although I do have various health problems, non of them affect my hands (or my legs for that matter). My problem was that the vibration from wood cutting started to make the hand sore between thumb and first finger, plus having to hold the trigger in as well, thus leading to tiredness in the hand. I suspect as well I may have been asking too much of the Skorpion.
Strangely, although there is still vibration when cutting metal, it doesn't seem as bad. I've used it on ¼" or 5/8" thick steel and ½" thick aluminium plate. For the steel I use plenty of oil, whilst the ali was cut dry.
|Ian S C||01/12/2010 12:07:59|
7468 forum posts
Don't know about nerves, but a 9" grinder without a soft start scared the ***** out of me the first time I used one.Ian S C
|1504 forum posts|
I regularly use a small (41/2",115mm) angle grinder to cut steel plate, and use discs that are 1mm thick, so they cut rather than grind their way through like the thicker ones do. They are fierce cutters, and can't be dropped on the work, but held in soft contact and using a straightedge produce a fine cut that needs little cleaning up.
Stand to one side of the grinder so it can't jump at you, think of using a STIHL stone saw and it's the same technique but much less tiring.
Always protect hands and feet, and if it jumps back it may hit you in the thigh., so think about that, it's a vulnerable area.
Always do my cutting outside, which lends a nice rusty patina to the paving slabs when it rains afterwards!
|Gordon W||02/12/2010 09:45:23|
|2011 forum posts|
Can I suggest using timber as a straight - edge when cutting with angle grinder, safer and kinder to discs? when worn can be re-cycled.
|Nicholas Farr||02/12/2010 10:17:24|
2549 forum posts
Hi Gordon, I wouldn't say it is any safer, as you can get undue drag against such things as wood, giving more tendancy for the grinder to be snatched out of your hands. One thing you should know about cutting disc is that they are only designed to cut on the egde of the disc, they should never be used as a grinding disc, it can be potentionaly dangerous. A piece of flat steel about 2mm thick is the best sort of thing and should be moved out of the way once you have a shallow cut into the surface of the piece you are cutting. Drag on the sides of a cutting disc should be avoided. Better still just follow the line.
Edited By Nicholas Farr on 02/12/2010 10:18:33
|Gordon W||02/12/2010 17:42:45|
|2011 forum posts|
That's the idea Nick, wood does not "grind" the side of the disc, steel does. BTW I'm assuming a 9" grinder. Should always be holding any tool so it cannot be snatched out of hand, that's what causes the accidents.
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