AR steel resistant to grinder attack?
AR steel resistant to grinder attack?
(OP)
Hi
I am creating an anti-theft automotive device which will be covered by a steel sliding box. Could someone advise me as to the best type of steel to specify that would be be most resistant to a cordless grinder/cutting disk attack.
I have looked at Abrasion resistant steel and case hardening but I am a lowly IT guy who has no such knowledge. I can go up to 3 or 4 mm thick and the box section is approx 20cm x 20cm x 30cm. Also what would be the implications of manufacturing. Can AR steel be easily worked/welded?
Hope its OK to pop up on this forum if not a professional.
Thanks Grouse
I am creating an anti-theft automotive device which will be covered by a steel sliding box. Could someone advise me as to the best type of steel to specify that would be be most resistant to a cordless grinder/cutting disk attack.
I have looked at Abrasion resistant steel and case hardening but I am a lowly IT guy who has no such knowledge. I can go up to 3 or 4 mm thick and the box section is approx 20cm x 20cm x 30cm. Also what would be the implications of manufacturing. Can AR steel be easily worked/welded?
Hope its OK to pop up on this forum if not a professional.
Thanks Grouse





RE: AR steel resistant to grinder attack?
Machining will be potentially a lot more expensive than lower performance materials would be.
You should also know going in (if you don't already) that building anything our of steel with the intent of protecting from a grinder is a losing game. Nothing will ever be grinder proof- it's just a question of how long.
RE: AR steel resistant to grinder attack?
For your case, think of a Kevlar wrap - you're looking for cut resistance, not fire-proofing. A hand-held battery-operated Dremel-type tool can't make a long cut through any of the heavier gauges. A six-inch Metabo commercial grinder running an 0.045 thick cutting wheel?
RE: AR steel resistant to grinder attack?
B.E.
You are judged not by what you know, but by what you can do.
RE: AR steel resistant to grinder attack?
1. The rotating spindle idea could easily be incorporated into my design to protect one of the most vulnerable parts. Is it the concept that the grinding wheel cannot get any purchase on it or does it need to have the spinning dressing wheels as part of it to wear down the disk?
2. Sandwiching is not something I had thought of but sounds effective. I assume the idea is to have long stranded fibres that wrap up into the grinding spindle to choke it. Kavala appears to be £100 per sqm so would over price the device I think.
Is there an industry method of manufacturing sandwich plate steel or is it literally get a fabricator to weld up each panel of my device manually inserting the fibre/cloth?
Really impressed with this forum that you guys are happy to share your knowledge with a non techy
Thanks again
Grouse
RE: AR steel resistant to grinder attack?
B.E.
You are judged not by what you know, but by what you can do.
RE: AR steel resistant to grinder attack?
RE: AR steel resistant to grinder attack?
Make a second, outer enclosure 3/8 inch larger on each side that is thicker. Made of more expensive steel if you wish.
Pack the space between the two with loose ball bearings whose diameter is larger than the thickness of the biggest grinding wheel you need to protect against. 1/4 inch wheel is about the thickest I've ever found commercially.
Thief tries to start grinding, gets through the outer enclosure. Ball bearings roll when hit, don't let the wheel get a grip. The bearings are too big to roll out of the groove cut.
RE: AR steel resistant to grinder attack?
RE: AR steel resistant to grinder attack?
Also, along the lines of the layering/sandwich idea. Some thick natural rubber or other elastomeric product sandwiched into the steel would not only gum up the grinding disc, but it's going to stink and smoke terribly.
Nothing will 100% deter an assertive thief, it's the time factor. Thieves don't want to hang around too long, as the odds for getting caught go against them the longer it takes to crack the target.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: AR steel resistant to grinder attack?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: AR steel resistant to grinder attack?
During the night, thieves had bypassed the alarm, they had opened the front office and carted the office safe onto the workshop floor. They had then used an Oxy Acetylene cutting torch to cut the back off the safe. They had removed about Ten pounds worth of petty cash and absconded.
Upon inspecting the safe I noted that the door and sides of the safe were massive, about 3" thick multi layered. The back where the thieves cut through was only one layer of 3/16" thick steel. The police said that they doubted that it took the thieves more than ten minutes to cut that safe open.
It was supposed to have been buried in a wall which it was not.
B.E.
You are judged not by what you know, but by what you can do.
RE: AR steel resistant to grinder attack?
The bendy idea where I assume the idea is to pinch the grinding wheel sounds very cool but alas doesn't suit my design.
Fortunately I have factored in the issue that a would be thief could just cut part of the car so hopefully that's dealt with.
hmmm ... ball bearings could be introduced, i have the space but I am thinking the rubber idea has legs for me. The smoke and stickyness could well do the job.
Should have realised a forum full of engineers would go above and beyond with ideas when given a problem :'D
Grouse