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Posted: 1/20/2013 10:41:14 AM EDT
Places specify the bolt is 158 carpenter, but don't explicitly say what the carrier steel is. Is it 8620?  Thanks.
Link Posted: 1/20/2013 10:45:13 AM EDT
[#1]
8620
Link Posted: 1/20/2013 10:47:23 AM EDT
[#2]
IIRC 8620 is correct.
 
Link Posted: 1/20/2013 10:54:39 AM EDT
[#3]
Hmm. I figured it'd be 4140. 8620 has to be carb and hard, which is what the m14 recievers were. It tends to distort a part that you want to finish before heat treat.
Link Posted: 1/20/2013 11:18:30 AM EDT
[#4]
Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.
Link Posted: 1/20/2013 11:30:33 AM EDT
[#5]



Quoted:


Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.


...what? One more time in English please.



 
Link Posted: 1/20/2013 11:33:52 AM EDT
[#6]
I use Zircaloy, but only for the actinide tips.

Link Posted: 1/20/2013 11:39:05 AM EDT
[#7]
Quoted:

Quoted:
Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.

...what? One more time in English please.
 


His hoovercraft is full of eels
Link Posted: 1/20/2013 11:59:29 AM EDT
[#8]
Sorry, on my phone at the gun show.
Ok, so my rguns 8620 carrier is g2g. It came from AIM with a 158 bolt, want to be sure about the carrier. Thanks guys.
Link Posted: 1/20/2013 12:06:47 PM EDT
[#9]
Quoted:

Quoted:
Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.

...what? One more time in English please.
 


8620 is a low alloy steel.  8620 needs to be carburized to obtain a hardness to prevent excessive wear.  The part  or parts would be placed in a controlled atmosphere furnace and heated to around 1700 plus degrees. While in the furnace carbon would be injected into the furnace. Normally you carburized to about .030.
Parts then have to be annealed, which is another heat and quench.  After this process parts will go to grinding or turning to finish to size.  Lots of bolt carriers are made from 8620.
Materials such as 4140 are high alloy steels. To get a surface hardness you would have to induction harden. Cheaper to carburized.  

158 carpenter steel is the material for mil spec bolts. It is a tool steel that can take a lot of shock.

I doubt the average guy who shoots a couple hundred rounds per year would break a bolt made from 8620.  

If you google these numbers with steel added you will get a good view of material and use.  

Coatings are then applied. Black oxidize is black rust.  There are new nickel boron coatings being used.

You will even see stainless bolt carriers.

I am no expert and I am sure someone will be along to give you the Arfcom reply.

Link Posted: 1/20/2013 2:20:09 PM EDT
[#10]
Quoted:
Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.


My word.  What did you just say?
Link Posted: 1/20/2013 2:23:26 PM EDT
[#11]
Quoted:
Quoted:

Quoted:
Ok perfect do my rguns 8620 carrier us g2g. It came from AIM with a 158 bolt, want sure about the carrier. Talks guys.

...what? One more time in English please.
 


8620 is a low alloy steel.  8620 needs to be carburized to obtain a hardness to prevent excessive wear.  The part  or parts would be placed in a controlled atmosphere furnace and heated to around 1700 plus degrees. While in the furnace carbon would be injected into the furnace. Normally you carburized to about .030.
Parts then have to be annealed, which is another heat and quench.  After this process parts will go to grinding or turning to finish to size.  Lots of bolt carriers are made from 8620.
Materials such as 4140 are high alloy steels. To get a surface hardness you would have to induction harden. Cheaper to carburized.  

158 carpenter steel is the material for mil spec bolts. It is a tool steel that can take a lot of shock.

I doubt the average guy who shoots a couple hundred rounds per year would break a bolt made from 8620.  

If you google these numbers with steel added you will get a good view of material and use.  

Coatings are then applied. Black oxidize is black rust.  There are new nickel boron coatings being used.

You will even see stainless bolt carriers.

I am no expert and I am sure someone will be along to give you the Arfcom reply.



That's all well and good, but he asked about the carrier, not the bolt.

IIRC OP, 8620 is mil spec for the carrier. Carpenter 158 for the bolt. I'm sure about the bolt material, not so sure about the carrier.
Link Posted: 1/20/2013 3:46:32 PM EDT
[#12]

I've got one that's aluminum.

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