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View Full Version : Has anyone worked with CADLOY armor ?



rdfeil
06-14-2010, 12:32 AM
Hi All,

I have a job coming up that may require some drilling in CADLOY armor plating. I have searched on-line and only found one mention of drilling this stuff and the suggestions were not promising :( . What I am doing is refitting the emergency lighting and communications systems in our county sheriffs 'Peacekeeper' swat vehicle. This may require me to drill a few holes for mounting equipment and routing wiring. I had been told that the outer shell of this thing was un-drillable in any normal way. I did try to drill it just to find out how it would react. The cobalt drill I tried is now slagg :eek: and the surface of the armor is barely scratched. It was a 1/4 inch drill bit trying to punch 1/4 inch armor plate. I went real slow with cutting oil and all that happened was that the bit overheated and turned to slagg.
It had been suggested to anneal the plating first, but this is not an option as the vehicle is freshly painted and detailed for the sheriff, so no burning the fresh paint :D . Any thoughts would be appreciated.

Robin

doctor demo
06-14-2010, 01:59 AM
No direct experience with cadloy, but You might try a good quality diamond core bit on a sample piece.

Steve

ckelloug
06-14-2010, 04:35 AM
Howabout a .243 armor piercing round :D

Davidhcnc
06-14-2010, 05:47 AM
Would the armour be compromised by drilling holes in it?

I would think the manufacturer and also the insurer will not be happy unless they approved the modification.

So I would use glue.

Evan
06-14-2010, 08:50 AM
I would expect it is just a version of high manganese steel, also known as a abrasion resistant plate or Hadfield steel. In the hard condition it is incredibly tough and nearly impossible to drill as it work hardens instantly the moment the material is disturbed in any way. The more it is disturbed the harder it becomes but it never becomes brittle. If you must cut it in the hard condition you must use a bit that does an absolute minimum of rubbing and has the sharpest possible edge. A brand new high quality carbide drill bit will work as I know from personal experience but may only last a few holes. Once the edge chips it is finished. Drilling holes will not compromise the armor unless somebody manages to shoot a round through the hole.

edit: You need a powerful drill motor and a chuck that will not slip on the bit. Use very heavy pressure and some cutting oil at low rpm.

lazlo
06-14-2010, 09:09 AM
I've never heard of CADLOY, but it's probably Milspec 12560 (Rolled Homogeneous Armor). There are class ratings (1 through 3, maybe higher?) with corresponding penetration specs.

http://www.aasteel.com/military.html

I'm told that it machines like Hasteloy, but a common substitution is 4340 HT. Think you'd have to EDM the holes/threads for something that hard.

wierdscience
06-14-2010, 09:17 AM
I drilled a bunch of holes in AR plate with a common masonary drill and coolant.You'll have to sharpen up the edges on a SC or Diamond wheel first,use lots of pressure and a low speed.

It would be better if you had acess to a mag drill also,it's gonna be hard to get enough pressure with a hand drill.

lazlo
06-14-2010, 09:26 AM
Darin, did you drill the armor plate after it was hardened?? Wow! :eek:

Willy
06-14-2010, 09:49 AM
If it's anything thing like drilling holes in a Hummer, Evan and Darin are definitely right.

Here's some tips for drilling holes into the Hummer's armor plate. (http://www.stormingmedia.us/45/4581/A458184.html)

lazlo
06-14-2010, 09:59 AM
If it's anything thing like drilling holes in a Hummer, Evan and Darin are definitely right.

Here's some tips for drilling holes into the Hummer's armor plate. (http://www.stormingmedia.us/45/4581/A458184.html)

Neat page, but they're using HSS drills and drilling/tapped before heat treat:

"After drilling, the plates are formed and shaped for installation. Anniston Depot had been using cobalt-high-speed-steel (HSS) drills while performing the drilling on a number of different machine tools."

Willy
06-14-2010, 10:35 AM
Robert, I gotta run run right now but will get back later with some evidence, but I remember reading an article, in I think Modern Machine Shop, a while back about armored vehicle manufacturing processes, and the plates were drilled and tapped in the hardened state as received from the mill prior to being formed.

Maybe I'm wrong, you know what they say about the mind being the first to go...well maybe not the first.:D

The link I gave though also gave me the impression that the plate was hardened already. I would think on large sections quality control of the end product would be more easy to maintain by procuring sheets from the mill in the hardened state rather than doing this in house.

Evan
06-14-2010, 10:45 AM
It would be better if you had acess to a mag drill also,it's gonna be hard to get enough pressure with a hand drill.


If it is manganese steel it is non magnetic.

lazlo
06-14-2010, 12:08 PM
If it is manganese steel it is non magnetic.

RHA is definitely magnetic. When I worked for Army Research Labs, we installed sensors on the M1 and Bradley armor with magnetic clamps.

rdfeil
06-14-2010, 03:19 PM
Hi All and thanks for the quick replies. Just a little more information...
Cadloy is a trade-name for the armor alloy used by the manufacturer of the vehicle which is Textron Marine. There is very little info on this alloy on-line. I only have to drill a few holes to mount the radio equipment so I think that I will try to sharpen a masonry bit and cross my fingers. The metal is magnetic if that helps. It is also supposed to be able to stop up to 7.62 mm AP rounds so I don't think I want to be that close to it if I tried to poke a hole that way :eek: . The ricochet and shrapnel might ruin my day. I understand that it is fairly easy to weld to the armor plating but they have already sent the rig to the paint shop so welding is out for now. I will keep you posted on my progress next week. Thanks to all for the replies.

Robin

Black_Moons
06-14-2010, 04:52 PM
Howabout a .243 armor piercing round :D
Hmm he mentions 0.250 holes required though, thats a little undersize.

Can you buy a 0.250 +-0.001 reamer round? :)
Or are you just hopeing for the 0.243 round to bore oversized? :P

Evan
06-14-2010, 05:06 PM
That material is a well guarded secret. The most I have been able to find is that it is an air hardening alloy steel. That means it is very difficult to anneal and welding doesn't weaken it. It also means that if it becomes the slightest bit hot while drilling it will become even harder. You need to rig a coolant supply while drilling. Soapy water will work fine. Get a plastic 2 gallon camping flexible water jug and hook a hose to it so that it can run over the work location as you drill.

wierdscience
06-14-2010, 07:21 PM
Textron,those are built AFIK less than 40 miles from here.I know a few guys that work there.

Maybe try calling the plant-

Textron Marine & Land Systems
2585 Front Street, Slidell, LA 70458-3935
(985) 690-4470‎

loose nut
06-14-2010, 08:15 PM
I wouldn't try annealing the plate to drill it. What good is "soft" armor plate, even in a small area it could fail if hit.

Willy
06-14-2010, 08:21 PM
A little more info on Cadloy armor plate.
Cadillac Gage (later to merge with Textron Marine & Land Systems), trademarked this proprietary ballistic armor in 1978. I would suspect this is were the Cadloy name for the alloy came from.
As Evan mentioned the properties of this alloy is a well kept secret.
But after a rather exhaustive search I did find that most ballistic armor is formed and machined with conventional tooling.

A couple of pdf's detailing the procedure for drilling holes in Humvee ballistic armor plate.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA481854&Location=U2&doc=GetTRDoc.pdf

http://www.dodtechmatch.com/Dod/TechAd/Document.aspx?ID=30206

Press brakes for forming armor plate into MRAP vehicle (mine-resistant-ambush- protected) V-hulls.
http://www.nsurepro.com/PressBrakes/

Another company that specializes in armor plate processing.
http://www.army-technology.com/contractors/ballistic_protection/mtlgroup/

Although the tooling and techniques are somewhat conventional, I'm sure glad I don't have to deal with armor plate machining. I believe though that once one has gone past the steep part of the learning curve, (as defense contractors obviously have) it just boils down to proper procedure.

But I must admit, not a hell of a lot of detail out there about armor plate material properties.

Evan
06-14-2010, 08:55 PM
I wouldn't try annealing the plate to drill it. What good is "soft" armor plate, even in a small area it could fail if hit.


It can't be annealed in place. To anneal air hardening steel alloys such as that requires a very slow and accurately controlled cooling profile over a time period of up to 72 hours.

fishfrnzy
06-15-2010, 12:28 AM
Looks like this guy had the same problem. This was not you was it. Looks like he's in Florida.

http://www.shopfloortalk.com/forums/showthread.php?t=14181

All AR ( abrasion resisting ) plate is not the same. Comes in many hardnesses.

AR235
AR321
AR360
AR400
AR450
AR500
AR550
AR600
AR w/5% up to 14% Manganese ( this one will get very hard very fast as the mangenese is high for this exact purpose ie impact resistance)

ThewThe AR550 and 600 are somewhat brittle ( if you beat on them when they are cold they can crack etc.

These are considered somewhat machinable until you get to about 550 BHN.




Armor plates are like the above but may have extra elements added to make them more tough and more shatter resistant. They also have balistic tests done to them. The info says the material is weldable which may help. since we dont know how hard it is except that it is probably about as hard as your cobalt bit, I think the diamond drill suggested above may be your best bet.

NzOldun
06-15-2010, 12:45 AM
You could try the old method for drilling glass - a hollow brass tube of the required diamter and fine valve lapping past. Relatively slow speeds and lots of 'pecking' to drill thru - keep adding small amounts of wet paste.

small.planes
06-15-2010, 04:22 AM
If you can find one a Stellite drill bit might do the job, IIRC they are designed for drilling hardened steels, in the 50+ RC range.
Not cheap though...

Hope you dont have to tap the holes as well :eek:

Dave

Ian B
06-15-2010, 05:31 AM
Is this stuf like hardox? If so, here's something on machining it:

http://www.aemach.com/pdf/Machining%20HARDOX%20and%20WELDOX.pdf

Looks straightforward - just clamp the vehicle into a (big) radial drill and go at it...

Ian

A.K. Boomer
06-15-2010, 08:38 AM
Id skip the drilling, It WILL compromise the integrity - yes highly unlikely that a round hits "the spot" but if its a round that almost gets through the regular stuff then it will have no problem ripping through the center of a drill spot,
plus it sounds like a PITA.

Go to an auto body shop and get some uni-body adhesive from them, after cured this stuff will literally tear metal before it lets go, plenty strong for what your using it for and you can hang from it if you want,,,
Just be sure you mount it where you want it cuz its not coming back off...

Willy
06-15-2010, 09:54 AM
Good point AK.
Is this the same adhesive GM uses for instance for mounting their door hinges to the bodies of pickups?
If it is, you're right on about the strength of this stuff, it's as strong as a good weld, and yes the metal will tear before it lets go!

ckelloug
06-15-2010, 10:22 AM
How about a call to masterbond inc and using a high strength epoxy. If chosen well, this may be sufficient for the mounting and avoid the holes/tapping completely.

Willy
06-15-2010, 10:32 AM
After doing a little look-see, I find that GM does not bond the door hinges to the cab. They are in fact welded and covered with sealer giving them the appearance of being bonded.
I was wrong...who would have guessed?:D

But after looking at some of the adhesives on the 3M site I'm still very impressed with the techniques and products used!

jeremy13
06-15-2010, 11:13 AM
Looks like a job for some well placed explosives to me. You can punch all the holes at the same time. With about 1/10 a second drill time.:cool:
http://bbs.homeshopmachinist.net/showthread.php?t=38813&highlight=punching+holes+in+steel

enginuity
06-15-2010, 12:19 PM
I'd try one of those ceramic tile drills with lots of coolant and pressure

rdfeil
06-16-2010, 12:04 AM
Thanks for keeping the ideas coming. The more I hear the more I am thinking that some form of adhesive mounting may be the better idea in this case. I will be able to thoroughly clean the interior surfaces where things need to be mounted on the floor. With that in mind a high strength epoxy holding down some shallow uni-strut would hold the radios, siren and lighting control unit with ease. This vehicle sees very little road time so vibration and road flex will not be a problem. Fortunately for me the exterior lights and light-bar already have mounting bosses welded to the body for me to use. Another plus for the epoxy is that I will not have to worry about what is on the other side of where I would be drilling :D and I won't have to worry about the pretty new paint on the outside for the side mounted equipment :rolleyes: . I will keep you posted when I get the rig back and start this project.

Robin

boslab
06-16-2010, 12:12 AM
stellite hardmetal drill will do it nicely, keep the pressure on it though
mark

Evan
06-16-2010, 12:14 AM
Another plus for epoxy is that is the one glue that has the same thermal expansion as steel so temperature changes won't cause it to crack, shrink expand or fall off. I think you would be best to use an epoxy that stays slightly flexible as it will take impacts better than a hard epoxy.

A good choice is Loctite E-90FL Hysol Flexible Epoxy. It is a general purpose, flexible, grey, impact resistant, adhesive with a 90-minute working life.

rdfeil
06-16-2010, 12:17 AM
Evan,
Thanks for the product number. I will go on a search tomorrow.

Boslab,
I will look into the drill you suggested.

Robin

lazlo
06-16-2010, 12:27 AM
stellite hardmetal drill will do it nicely, keep the pressure on it though

Seriously? I run Stellite lathe tools, and although they have good red hardness, and very high toughness, they're quite a bit softer than carbide.

It sounds like you've done this, but I would think a carbide drill would work a lot better, like Darin proposed on the second page :)

boslab
06-16-2010, 12:31 AM
stellite hardmetal drill will do it nicely, keep the pressure on it though
mark
just remembered where i got the last ones
http://www.cromwell.co.uk/DEL0265050A?id=M8gojDUz, interestingly we just finished making about 250 tons of this stuff last night;
http://www.defensereview.com/super-bainite-steel-armor-for-armored-vehicles-super-armor-on-the-cheap/
it was a bloody nuiscance so set up the spectrometers for it so i'm going to bed
mark

lazlo
06-16-2010, 12:39 AM
just remembered where i got the last ones
http://www.cromwell.co.uk/DEL0265050A?id=M8gojDUz

Well I'll be damned -- that's pretty slick!

"The Stellite drill generates intense localised heat which softens the steel at the drill point. As the Stellite alloy has a high degree of red hardness it does not anneal with this heat but continues to operate, actually cutting its way through as evidenced by the chips produced. "

Willy
06-16-2010, 01:06 AM
Not suitable for this particular application. But I wonder if flow or thermal drilling could be used to advantage in armor plate?

Thermal drilling (http://www.youtube.com/watch?v=NhkWINPRK3A)

ptjw7uk
06-16-2010, 04:23 AM
Just found this on the web, for a humvee
https://www.ncdmm.org/docs/d/HumveeUparmor.pdf?rdm=69877894

Peter

Evan
06-16-2010, 06:31 AM
It occurs to me that if using the epoxy you should use your handy Dremel style grinder to clean and rough up the area to which the epoxy will be applied. I suspect that the armour product will have some sort of surface finish applied to prevent corrosion which should be removed for best results. This also includes the mating surface, especially if it is aluminum.

The flexible epoxy will accommodate the difference in thermal expansion but aluminum has an oxide layer that forms nearly instantly on exposure to air. To obtain best results with bare aluminum the surface should be abraded and the glue applied. Then with the glue to prevent further exposure to oxygen the surface should be further abraded by scratching through the epoxy with a sharp instrument.

lazlo
06-16-2010, 10:08 AM
Just found this on the web, for a humvee
https://www.ncdmm.org/docs/d/HumveeUparmor.pdf?rdm=69877894

That's the link that Willy posted:


"Anniston Depot had been using cobalt [i.e., Stellite] high-speed-steel (HSS) drills while performing the drilling on a number of different machine tools."

The Kennametal K7515 and K211-HP solid carbide drills recommended by the NCDMM feature special tip geometries and hard coatings that, in combination with through-coolant, permit the use of more aggressive drilling parameters and also produce increased tool life.

The new drilling setup increased drill life by forty times. The cobalt-HSS drills could complete 30 holes before wear required them to be changed, while the solid carbide drills produced 1200 holes before wear became significant."

It sounds like the cobalt (Stellite) drills are the way to go if you're a job shop. The high-tech Kennametal coolant-fed carbide drills are probably very expensive.

boslab
06-16-2010, 09:01 PM
i dont like to totally disagree with Evan as i think he is one smart guy but epoxy wont hold, it blows away [found after testing with BIG rounds] it damps well but a few mechanical fixings help, 18/8 high tensiles seeem to do the trick.
Strange that i ended up making armour for tanks, i thought it was too strong to make coke tins out of, they lied, they said it was "tin arseholes for teddybears" oh crap another nightshift, will this lab ever behave, at least i can lock the office door to keep the dull twats out
mark

Evan
06-16-2010, 10:36 PM
Mark,

This isn't a battle tank. The armour in question is only rated to stop a 7.62mm full metal jacket ball round. Not armour piercing and not 50 BMG. It is designed to protect a swat team from a retard shooting in their general direction with a handgun as they prepare to terminate with prejudice. I am quite sure that the epoxy will fail if it gets hit with something big, but then so will the armour. My 50 cal replica Hawkin Mtn rifle will project a 300 grain Miniť ball at around 2000 fps and will punch a fist sized hole in 1/4" boiler plate. That will loosen just about any kind fastening, screwed or glued. Most bad guys use hand guns, shotguns and small caliber rifles these days. Not a lot of idiots holding up banks with hunting rifles.

ckelloug
06-16-2010, 11:54 PM
If all you're doing is gluing on antennas and handles, it doesn't matter if the epoxy fails if it is hit. If you get hit in a way that fails the epoxy, the piece it's holding is also likely to be damaged. The point of using epoxy is that you can do the entire install without compromising the armor. Anything outside the armor is by definition already sacrificial.

If the proper epoxy spontaneously unglued itself in critical situations, we would not have airplanes built out of epoxy composites. I have a piece of the carbon fiber skin from the C-17 sitting on my desk. The import thing is to use the right epoxy with the right surface preparation and primers. Like I said before, talking to an apps engineer at a place like masterbond who makes epoxies for critical applications can help select the right one. Just going out and haphazardly getting hardware store epoxy might not be the best choice.

lazlo
06-17-2010, 12:13 AM
If all you're doing is gluing on antennas and handles, it doesn't matter if the epoxy fails if it is hit.

I'd bet a cold beer that there's a MilSpec on how armor should be attached to military vehicles. I would be truly surprised if epoxy was allowed.

Evan
06-17-2010, 01:16 AM
Like I said before, talking to an apps engineer at a place like masterbond who makes epoxies for critical applications can help select the right one. Just going out and haphazardly getting hardware store epoxy might not be the best choice.


The epoxy I recommended is the best choice for the job described. It replaces the nasty but effective polysulphide based sealants/glues that used to be used to glue aircraft floats togethern (among many other things). Aircraft floats take a bigger pounding on a routine basis than just about any other part of an aircraft. The Hysol line was developed because most polysulphides are hexane solvent based. They also tended to contain considerable quantities of PCBs. It is very expensive these days to use polysulphide glues because of the safety requirements.

Hysol E90FL has a shear strength of 800 psi on bare steel and 3000 psi on properly prepared aluminum. It is an industrial application adhesive.