Best use of hard plate

[Lelandwelds]

What is the current thinking on the best way to use hard plate? I've seen some safes where it actually is free to wiggle a surprising amount. ( to break drills, maybe?) In others, it is rigidly fixed.

Has anyone ever forged ripples or sine wave shapes into hard plate to break drills?

[cledry]

What is the current thinking on the best way to use hard plate? I've seen some safes where it actually is free to wiggle a surprising amount. ( to break drills, maybe?) In others, it is rigidly fixed.

Has anyone ever forged ripples or sine wave shapes into hard plate to break drills?

Good question. IMHO hard plate is best when used in tandem with a glass relocker plate, I think the newer thought on having them free to wiggle a bit makes more sens, plus it can be replaced easily. I am not sure about forging ripples in it, but a matrix with carbide and or ball bearings seems to be some of the tougher stuff to deal with.

[gumptrick]

I have zero experience with safes or safecracking, but I do have a lot of experience with machining. You can drill, saw, or otherwise cut just about any kind of metal, even very hard steels. However, doing so requires a very rigid setup. If there is any kind of looseness or wobbling that will break tools. This is especially true because hard materials call for tungsten carbide tools. They are hard enough to cut full-hard tool steel, etc. However, they are also brittle, which makes a rigid setup a must. You can easily drill a hole through hard steel if you have a milling machine or an industrial drill press that weighs 1000's of pounds. But with a hand drill? The lack of rigidity is going to stop that.

Likewise, anything that presents an inconsistent or "interrupted cut" will make drilling/machining a lot more difficult. A solid piece of tool steel is easier to drill than a piece of aluminum that is packed with random bits of tool steel because the former presents a smooth uniform surface to the drill whereas the latter has lots of edges that can catch and break the drill.

So, from a machinist's perspective, anything you can do to make the hardplate irregular in shape or able to move slightly would work very well in being able to defeat drill or saw attacks. A great DIY method would be to get some abrasion-resistant steel like AR500 and then weld hardfacing on the top of it. Deliberately make the welding sloppy, exaggerate your passes to make a washboard sort of surface, etc.

[Lelandwelds]

My big metal box is padlock based so the glass relocker isnt practical. My nearest place for new AR500 is DFW or Houston . I can get some 1045 from San Antonio. Both materials are available mostly in full sheets. I can mail order small pieces of knife steels cheaply.

That bit about carbide and aluminum is interesting. The local machine shops sell scrap carbide for $6 or $7 a pound. I can easily melt scrap aluminum with air/propane. I could rig up a fixture to shatter and contain the old tooling. I guess it wouldnt matter if it was WC, M4, or HSS?

Now that I think about it, I have broken cutters just because I got something stuck under the mag drill base.

[GWiens2001]

OK, I'm deleting the last two posts. Guys, this is the open forum, so destructive entry can not be discussed.

Gordon

[gumptrick]

That bit about carbide and aluminum is interesting. The local machine shops sell scrap carbide for $6 or $7 a pound. I can easily melt scrap aluminum with air/propane. I could rig up a fixture to shatter and contain the old tooling. I guess it wouldnt matter if it was WC, M4, or HSS?

Now that I think about it, I have broken cutters just because I got something stuck under the mag drill base.

A couple things to think about:
1) You can often get smaller pieces of AR500 by mail order since it's commonly used to make steel targets for pistol/rifle shooting.

2) I talked to a buddy over the weekend who told me he's made "hardplate" by brazing a bunch of scrap/broken carbide tool inserts to a steel plate. That's a brilliant idea, actually. He just put brazing paste on a steel plate, scattered the broken carbide on top, and heated it with a rosebud.

[Lelandwelds]

I dont think LFB bronze will work with tunsten carbide. I have never tried it. Thats a small fortune if I use silver.

[gumptrick]

I dont think LFB bronze will work with tunsten carbide. I have never tried it. Thats a small fortune if I use silver.

I'm not sure either. The only times I've brazed carbide I used silver-cadmium.