How thick should a crush washer be. I think I got sold some used one's.

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[ARCHIVED THREAD] - How thick should a crush washer be. I think I got sold some used one's.

Posted: 1/25/2009 11:50:50 AM EDT

I went to the gun show yesterday and picked up a couple of crush washer's. Comparing them to my original used one, they look no differant. My original used one measure's .144"/3.66mm. One of the new one's measure .144"/3.66mm the same as my used one, and the other measure's .148"/3.76mm. To me, that's not much differance. Should I go with the thickest one, or is it used also. I hate to spend $8 to ship a $2.50 washer. But if I have to, I have to.

Any chance someone could mic one and tell me what it's supposed to measure. Thank's.

Posted: 1/25/2009 12:31:54 PM EDT

[#1]

Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Posted: 1/26/2009 6:01:45 PM EDT

[#2]

I'm talking about the crush washer. Take a look at my other thread.

http://www.ar15.com/forums/topic.html?b=3&f=4&t=421299

Consinsous seem's to be it's a one time use thing. But I sure don't see what get's crushed. I guess I just gotta have faith that it does.

Posted: 1/26/2009 7:12:59 PM EDT

[#3]

Quoted:

Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Returns to shape when removed? That dont seem right...what is the point in putting a new one on when changing FH's, then??

Posted: 1/26/2009 7:27:48 PM EDT

[#4]

It wouldn't be called a crush washer if you could use it twice

Posted: 1/26/2009 8:10:50 PM EDT

[#5]

Quoted:

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Returns to shape when removed? That dont seem right...what is the point in putting a new one on when changing FH's, then??

I think it's an old wive's gunsmith's tale. The crush washer seems to be pretty resilient. Kinda like spring steel.

Posted: 1/26/2009 8:12:54 PM EDT

[#6]

Quoted:
It wouldn't be called a crush washer if you could use it twice

Sure it would be. "Crush" differentiates it from "peel". It isn't destroyed in the process. Haven't you guys ever worked on your own rifles? Tell me you do not understand the characteristics of a crush washer.

Posted: 1/26/2009 8:28:29 PM EDT

[#7]

Quoted:

Quoted:
It wouldn't be called a crush washer if you could use it twice

Sure it would be. "Crush" differentiates it from "peel". It isn't destroyed in the process. Haven't you guys ever worked on your own rifles? Tell me you do not understand the characteristics of a crush washer.

I do not understand the characteristic's of a crush washer. Please explain.

Posted: 1/26/2009 8:38:57 PM EDT

[#8]

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Nope, a crush washer permanently deforms when used. A lock washer like used on A1 hiders will spring back out.

Posted: 1/26/2009 8:44:26 PM EDT

[#9]

So back to the original question. Anyone have a new crush washer they can mic.

Posted: 1/26/2009 8:46:14 PM EDT

[#10]

Quoted:

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Nope, a crush washer permanently deforms when used. A lock washer like used on A1 hiders will spring back out.

I have never removed a crush washer that remained flat upon removal.

Posted: 1/26/2009 8:48:00 PM EDT

[#11]

Quoted:
So back to the original question. Anyone have a new crush washer they can mic.

I would dive right in and help, but I'm on the road and away from my bench.

All the other fine gentlemen in this thread must have mics and plenty of crush washers to play with.

Posted: 1/26/2009 9:03:04 PM EDT

[#12]

Quoted:

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Nope, a crush washer permanently deforms when used. A lock washer like used on A1 hiders will spring back out.

I have never removed a crush washer that remained flat upon removal.

Every one I have installed then removed was deformed. They do not get crushed completely flat (unless you did something very very wrong) so that may be what you are seeing.

The only new crush washer iI have is for a .308 hider so I doubt it would be useful to measure against a 5.56

Posted: 1/26/2009 9:15:16 PM EDT

[#13]

Quoted:

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Nope, a crush washer permanently deforms when used. A lock washer like used on A1 hiders will spring back out.

I have never removed a crush washer that remained flat upon removal.

Every one I have installed then removed was deformed. They do not get crushed completely flat (unless you did something very very wrong) so that may be what you are seeing.

The only new crush washer iI have is for a .308 hider so I doubt it would be useful to measure against a 5.56

Would you agree that since all 3 of mine mic out almost the same measurment, the two that I just bought are used.(measurement's in first post)

Just for shit's and grin's, how about a measurement.

Posted: 1/26/2009 9:24:27 PM EDT

[#14]

They are reusable.

Posted: 1/26/2009 9:51:59 PM EDT

[#15]

Quoted:

Quoted:
Are you thinking of a peel washer? The layers on one are peeled off to make the flash hider time to TDC.

A crush washer is concave and simply flattens when the flash hider is tightened. It returns to shape when the flash hider is taken off. I would expect the measured thickness to remain the same as when new.

Nope, a crush washer permanently deforms when used. A lock washer like used on A1 hiders will spring back out.

I have never removed a crush washer that remained flat upon removal.

Every one I have installed then removed was deformed. They do not get crushed completely flat (unless you did something very very wrong) so that may be what you are seeing.

The only new crush washer iI have is for a .308 hider so I doubt it would be useful to measure against a 5.56

Would you agree that since all 3 of mine mic out almost the same measurment, the two that I just bought are used.(measurement's in first post)

Just for shit's and grin's, how about a measurement.

My used 5.56 one is .145 thick and my .308 one is .150. On the used 5.056 there is a pronounced lip on the back side that seats against the barrel shoulder. The new ones does not have this lip.

[ARCHIVED THREAD] - How thick should a crush washer be. I think I got sold some used one's.

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