What is meant by spalling?
- Thread starter Dano4734
- Start date
Model12Win
Moderator
The old 55 grain M16 bullet would spall on the target, leading to a massive stop rating.
"The old 55 grain M16 bullet would spall on the target, leading to a massive stop rating."
It's the target that "spalls"." Usually a "hardened" plate type target will spall when hit by a "hard" bullet rather than dent/perforate as a softer plate does.
"The old 55 grain M16 bullet" often tumbled and broke in 2-3 pieces resulting in some nasty wounds.
It's the target that "spalls"." Usually a "hardened" plate type target will spall when hit by a "hard" bullet rather than dent/perforate as a softer plate does.
"The old 55 grain M16 bullet" often tumbled and broke in 2-3 pieces resulting in some nasty wounds.
tango1niner
New member
Mobuck and DPris got it. A tank turret is hardened steel. When hit on the outside by lets say another tank round that DOES NOT penetrate the turret, steel on the inside of the turret can break away in fragments or "spall" incapacitating or killing the crew.
Reactive armor on the outside of the tank is used to redirect or "counter act" the incoming rounds energy and destructive forces.
Reactive armor on the outside of the tank is used to redirect or "counter act" the incoming rounds energy and destructive forces.
Jim Watson
New member
The British had HESH shells for tank and antitank guns. High Explosive Squash Head. In the sub microsecond realm, it would flatten against armor before exploding, causing a maximum of interior spalling onto crew, fuel, and ammo. I don't know what they use now against composite and reactive armor, probably high velocity hard penetrators like we do.
So if a 50 cal round hits a brick wall and the concrete shards fly back at the bad guys it’s spalling. If the round breaks apart it’s fragmented. Correct. That’s how I always understood it but I saw posts on vests talking about spalling referring to the round breaking apart not the vest plate
The correct use of the term refers to pieces of the object STRUCK, flying off, not the pieces of the striking object.
This first became widely known from WW I tanks, and still is an issue, but not to the degree it was then, or up through early WWII. The worst offenders were tanks with brittle hard armor plate, and those with riveted construction.
Especially the rivets. Rounds striking the rivet heads on the outside of the tank frequently broke the rivets, sending high speed metal fragments around inside the tank. Very bad for the crew.
Like every other technical term in English, there is a correct definition, and then there is the way people use it incorrectly in common speech.
Many people refer to shell fragments and spall as "shrapnel" but while the common use today, tis technically incorrect. They are fragments, not "shrapnel". But, like Kleenex and Band-Aids it has become the generic term used.
This first became widely known from WW I tanks, and still is an issue, but not to the degree it was then, or up through early WWII. The worst offenders were tanks with brittle hard armor plate, and those with riveted construction.
Especially the rivets. Rounds striking the rivet heads on the outside of the tank frequently broke the rivets, sending high speed metal fragments around inside the tank. Very bad for the crew.
Like every other technical term in English, there is a correct definition, and then there is the way people use it incorrectly in common speech.
Many people refer to shell fragments and spall as "shrapnel" but while the common use today, tis technically incorrect. They are fragments, not "shrapnel". But, like Kleenex and Band-Aids it has become the generic term used.
The context I have most often heard that word used lately has been with regards to AR 500 body armor. Customers are usually given the option to order a built-up coating of something like Line-X to try to capture bullet fragments after they hit the hardened steel plate. Without it fragments would follow the plate and had upwards or downwards embedding a bit into one’s neck. I’m not sure how well it works. I think welding a small lip onto the edges would work much better to redirect fragments back forward again.
I believe that the most precise, yet general definition is flaking or breaking off of fragments from a hard surface due to pressure or impact. concrete will spall, with flakes cracking off. bearings will spall with flakes if the pressure place on them is too high. Steel can deform, or splatter, but spalling is technically only when fragments break loose only by impact force, not mechanical tearing.
A marble on a window will pop a cone shaped bit from the inside, this is spall. flakes of metal popped off the back of steel after impact is. Pounding on steel with a hammer causes it sometimes.
If a person is hammering badly poured concrete, two things are going to happen. Direct pounding of that steel hammer will shatter and grind some of it to dust and sand. areas not necessarily under direct impact will flake or crumble just from the shock and the pressure being pushed sideways against it as the hole is punched. Everybody who has led an active life as a handyman or other user of tools, or even watched work done, will have seen it sometimes.
A marble on a window will pop a cone shaped bit from the inside, this is spall. flakes of metal popped off the back of steel after impact is. Pounding on steel with a hammer causes it sometimes.
If a person is hammering badly poured concrete, two things are going to happen. Direct pounding of that steel hammer will shatter and grind some of it to dust and sand. areas not necessarily under direct impact will flake or crumble just from the shock and the pressure being pushed sideways against it as the hole is punched. Everybody who has led an active life as a handyman or other user of tools, or even watched work done, will have seen it sometimes.
"...The old 55 grain M16 bullet would spall on the target..." That's not spalling. That's the bullet disintegrating. Also known as rapidly expanding upon impact just like any varmint bullet.
"...known from WW I tanks..." Known long before W.W. I. Concrete, wood and stone emplacements/walls will spall when hit by cannon fire too. Same results. A wood fragment is just as deadly as concrete, stone or steel too.
"...British had HESH shells..." So did/does everybody else. Lets a less powerful gun kill armoured vehicles using the magic of physics.
"...a small lip..." Nope.
"...known from WW I tanks..." Known long before W.W. I. Concrete, wood and stone emplacements/walls will spall when hit by cannon fire too. Same results. A wood fragment is just as deadly as concrete, stone or steel too.
"...British had HESH shells..." So did/does everybody else. Lets a less powerful gun kill armoured vehicles using the magic of physics.
"...a small lip..." Nope.
Jim Watson
New member
Another problem with riveted armor was that a hit on a seam could extrude projectile material through the gap. Think of flying razor blades. Spatter is the term I recall. Overlaps and reinforcing strips added protection but were not a complete defense against the energies applied.