Author Topic: Rockwell Results (Read 2555 times)

pills · « **on:** December 09, 2006, 02:03:58 PM »

As promised I am posting the results of the Rockwell test on my frames.

H&R Topper Buck "Model 162" No Serial Number 27

NEF Huntsman/tracker NW xxxxxx 27

NEF Handi rifle 30-06 SB2 NJ xxxxxx 26

None of my frames are color case hardened. My friend had two that we tested as well. They tested at around 33. Both are off of SB1s.

I would like to add that the stamp on the inside of the SB2 frame is 12 as I have seen on this forum before. Also would like to add that you can definately see the casting marks.

Mac11700 · « **Reply #1 on:** December 09, 2006, 02:41:59 PM »

I for 1 would like some explaination on how this test was preformed...According to you...the sb1 is a stronger frame...

Mac

pills · « **Reply #2 on:** December 09, 2006, 02:47:39 PM »

http://www.gordonengland.co.uk/hardness/rockwell.htm

The test was performed on three different areas of an open frame. The three were added together and divided by 3. The differences in locations were small. Actually the difference of the frames is very little.

kennyd · « **Reply #3 on:** December 09, 2006, 02:49:24 PM »

The 4140 (chrome moly) we use at work is right around 26 Rockwell C. I don't know what NEF uses for the frame, but 4140 is a probable guess. Up to around 45 you can still machine the stuff. Case hardening should be around 60 or more, but is thin. Not all of a heat treated part will be the same, depending on the draw and section through the piece. Where did you put the cone, and how sophisticated a machine did you use; there are hand ones, and bigger expensive ones like a heat treat facility uses.

pills · « **Reply #4 on:** December 09, 2006, 02:56:51 PM »

As for the questions about drawing and sectioning I cant answer. As for the machine: This machine is used on airplane cranks and such and he is regulated by the FAA.

MSP Ret · « **Reply #5 on:** December 09, 2006, 03:12:28 PM »

It could be hard but couldn't it be brittle? What does this actually prove to us regarding the strength of the frame? I am not knocking it, I am happy it was done. I just would like more answers and interpertation of the numbers so can understand what it means to me and how it affects my barrel and frame match ups. Thanks for your efforts and those of your friend....<><....

pills · « **Reply #6 on:** December 09, 2006, 03:16:55 PM »

I am sorry that I dont understand your question MSP Ret...

What it tells me is the strength of the material used in these frames is close to identical. Since I first found out about these guns I have been intriged by the supposed differences in SB1 and SB2. I have yet to find any tangible difference.

quickdtoo · « **Reply #7 on:** December 09, 2006, 03:28:13 PM »

I think Fred stated the reason why rockwell hardness is of little value as far as tensile strength is concerned. We already know that an SB1 frame won't handle a high pressure round, just ask MtJerry what happened when he unknowingly put his .270 barrel on one!! I'll post a link to the thread tomorrow if Matt gets the search working.

Tim

Quote from: Fred M on December 06, 2006, 08:06:22 PM

Pills
The Rockwell hardness test is performed only on heat treated steel. Never heard of being used on cast iron. As a matter of fact how do you heat treat cast iron. I think if you quenched red hot cast iron it would crack. Besides hardness would tell you nothing, cast iron is quite hard but has very low tensile strength and used only in low stress applications.

pills · « **Reply #8 on:** December 09, 2006, 03:33:00 PM »

I think Fred is wrong. If you look @ the link I posted they give information on all types of material even plastic.

quickdtoo · « **Reply #9 on:** December 09, 2006, 03:35:48 PM »

He may be, but that doesn't change the fact that an SB1's strength isn't close to that of an SB2, Jerry's .270 event proved that without a doubt!! $:-\$

Tim

pills · « **Reply #10 on:** December 09, 2006, 03:37:37 PM »

Forgive me for questioning but since I missed the post that confirmed without a doubt what makes the SB2 stronger than a SB1?

quickdtoo · « **Reply #11 on:** December 09, 2006, 03:48:15 PM »

Here's Jerry's thread...

Tim

http://www.graybeardoutdoors.com/smf/index.php/topic,66901.msg406756.html#msg406756

pills · « **Reply #12 on:** December 09, 2006, 03:54:09 PM »

Thanks for that post. Again I ask: What makes a SB2 frame stronger than a SB1?

Let me ask another question while I am at it? What qualifies as a "high pressure round"? How about a 22 hornet. I remember reading a link someone posted about pressures and it seems that one ranked pretty high.

Can we agree the 22 hornet round on a SB1 frame is acceptable?

kennyd · « **Reply #13 on:** December 09, 2006, 04:03:42 PM »

Don't think anyone said the frames were iron. A forging would also show tool marks. Castings can be steel, iron, aluminum, or palstic. We heat treat cast 4140 at work. Plain low carbon steel (1018) also tests around 26. Rockwell also has a B scale for softer stuff. If you run a machine you will find that some things are nasty (nickel), some are nice, and some of the best are alloys made to be pure (1144 one of the best for finish, size, and strength). I know strength comes from more than hardness, some steels will stretch, some will break. for exanple Think of the different nails you have used, ever have the ones that bend, or the ones that will go into concrete, they are all steel, just different alloy and heattreat.

quickdtoo · « **Reply #14 on:** December 09, 2006, 04:06:31 PM »

H&R considers all of the asterisk marked calibers on the acc barrel list as high pressure rounds that they won't fit to pre '99 frames, there are some discrepancies in the list that I pointed out in the Hornet thread. I feel that as long as there are no danger signs associated with shooting the Hornet on an SB1 frame, it should be fine. Those are primer anomalies due to the larger firing pin and hole around the pin, poor latch engagement and subsequent pop opens, and possibly stuck brass from too much frame flex. H&R has stated that SB2 frames are heat treated, but that is not likely the only difference as there is a an obvious difference in their appearance.

Tim

pills · « **Reply #15 on:** December 09, 2006, 04:07:12 PM »

I would think by the quote of Fred he is implying they are cast iron. Look @ the quote by quick about four posts up.

quickdtoo · « **Reply #16 on:** December 09, 2006, 04:56:03 PM »

I have to add a caveat to my previous statement on using an SB1 frame for centerfire cartridges other than shotgun. Each frame is different and what may work fine on one, may not on another, so a blanket statement that shooting a Hornet barrel on all SB1 frames is Ok, isn't what I want to convey, just use caution when doing so, it would be a shame to ruin a perfectly good frame, let alone risk injury.

Tim

Fred M · « **Reply #17 on:** December 09, 2006, 06:02:58 PM »

You guys can argue all you want, but the SB2 frame is made as an investment casting with high quality steel with a tensile strenfth of 85kpsi +. Depending on the stress it subjected to it will also be heat treated. This type of steel is expensive since it has to stand up to high pressure cartridges like the 270 and others. What ever stress is created a safety factor of about 50% is included in the structure.

We also know that high pressure loads will impact the underlug which is made of a softer steel this is a build in safety feature in case of a high pressure accident.
Remember the wrong 7.52x39 load in a 243. Well not much happened to the gun or the shooter because the stress was releaved by the compacted underlug.

I also said that I don't know the make up of the SB1 frame alloy casting if it is an alloy but ordinary cast iron of 18-23 kSI ultimate tensile strength would take care of the requiremnts of the contemplated use.

Hardness of the casting iron is not a requirement, since cast iron it is plenty hard. Case hardning adds nothing to tensile strength.

That is why I said the Rockwel test is of no use. H&R frames are made with econmy in mind, if they thought they could use all their calibers with the SB1 frame, why make an SB2.

The obvious argument is that the SB1 frame is not to used for rifle cartridges and that is the bottom line. I don't know if my figures are 100% correct but thay are close enough to have some valitity.

Here we go, believe nothing that you hear and only halve of what you see. Who said that?

.

quickdtoo · « **Reply #18 on:** December 09, 2006, 06:08:37 PM »

Maybe a call to Gordon on Monday will shed some light on the subject, eh??

Tim

Mac11700 · « **Reply #19 on:** December 10, 2006, 04:17:41 AM »

You can bet there will be a call made to him and futher up if need be...and probably more than just the 1...I have a issue with what pills had said...

Quote

Also would like to add that you can definately see the casting marks.

..This tells me something is wrong...In all of the SB-2 frames I have...You cannot see any of the casting marks...but on every SB-1 frame I've owned you can...The casting marks I am refering to are the ones that you can actually see the seems of the reciever not the indents that are put on the bottom...My recievers bottoms are completely smooth on their entire widths and lenghts on the inside..You cannot see where the pieces are joined...like you can on all of the SB-1 frames I've owned...

Mac

Fred M · « **Reply #20 on:** December 10, 2006, 06:32:23 AM »

There are really no pieces joint together. What you see are the joints of the mould.
Moulds are made with several pieces so you can get them appart. The casting is homogeneous. There are practically no actions made anymore from a solid billet.

When the casting is machined to its final dimension these mould joints disappear.
It is obvious the the SB1 frame gets less final machining if you can see the mould joints. That is simply cosmetic. and has no bearing on strength.

Mac11700 · « **Reply #21 on:** December 10, 2006, 06:48:19 AM »

Quote from: Fred M on December 10, 2006, 06:32:23 AM

There are really no pieces joint together. What you see are the joints of the mould.
Moulds are made with several pieces so you can get them appart. The casting is homogeneous. There are practically no actions made anymore from a solid billet.

When the casting is machined to its final dimension these mould joints disappear.
It is obvious the the SB1 frame gets less final machining if you can see the mould joints. That is simply cosmetic. and has no bearing on strength.

That's what I figured Fred...and I've looked at my SB-2 frames I have on hand...and none of them have the stamped numbers in them either...The casting lines I am refering to is in this pic...This was off my Topper Delux Classic 12ga...look directly in the center of the reciever...

Mac

quickdtoo · « **Reply #22 on:** December 10, 2006, 06:53:35 AM »

Appearance difference between SB1 and SB2 can be seen in this thread from a previous discussion which is in the FAQ.

Tim

http://www.graybeardoutdoors.com/smf/index.php/topic,80979.msg498556.html#msg498556

Fred M · « **Reply #23 on:** December 10, 2006, 07:48:28 AM »

Busta had this to say,These are the three things that jump out at you. Of course the SB-2 frame is also much harder and just has a certain feel and sound to it when installing barrels.

Which is indeed a very interesting observation. If you hang a piece of good steel on a string and tap it with another piece of steel you will hear a ring.
Not so with cast iron, it does not ring.

McLernon · « **Reply #24 on:** December 10, 2006, 07:56:19 AM »

Cast iron will have a very hard surface that results from faster cooling at the surface thus a hardness test, particularly Rockwell, will give a high AND misleading result. The Brinell Hardness Number(BHN) is a better measure of strength but only on thick enough sections. Rockwell C or B does not correlate well to the BHN. So your data doesn't mean much with respect to tensile strength. Case hardening only hardens the surface so no overall stength benefit is obtained.

McLernon

pills · « **Reply #25 on:** December 10, 2006, 08:30:28 AM »

Quote from: Fred M on December 09, 2006, 06:02:58 PM

You guys can argue all you want, but the SB2 frame is made as an investment casting with high quality steel with a tensile strenfth of 85kpsi +. Depending on the stress it subjected to it will also be heat treated. This type of steel is expensive since it has to stand up to high pressure cartridges like the 270 and others. What ever stress is created a safety factor of about 50% is included in the structure.

We also know that high pressure loads will impact the underlug which is made of a softer steel this is a build in safety feature in case of a high pressure accident.
Remember the wrong 7.52x39 load in a 243. Well not much happened to the gun or the shooter because the stress was releaved by the compacted underlug.

I also said that I don't know the make up of the SB1 frame alloy casting if it is an alloy but ordinary cast iron of 18-23 kSI ultimate tensile strength would take care of the requiremnts of the contemplated use.

Hardness of the casting iron is not a requirement, since cast iron it is plenty hard. Case hardning adds nothing to tensile strength.

That is why I said the Rockwel test is of no use. H&R frames are made with econmy in mind, if they thought they could use all their calibers with the SB1 frame, why make an SB2.

The obvious argument is that the SB1 frame is not to used for rifle cartridges and that is the bottom line. I don't know if my figures are 100% correct but thay are close enough to have some valitity.

Here we go, believe nothing that you hear and only halve of what you see. Who said that?
.

So which is it Fred: Is an SB1 Cast iron? One word answers help take away wiggle room. In the other post you definately implied it is cast iron.

Since you "know" "the SB2 frame is made as an investment casting with high quality steel with a tensile strenfth of 85kpsi +"
maybe you could enlighten the rest of us uninformed populas what a SB1 frame is made of.

Your obvious argument "that the SB1 frame is not to used for rifle cartridges and that is the bottom line " doesnt hold water in my cup. Maybe you want to re-evaluate the "validity" of your statement.

As for your statement "Here we go, believe nothing that you hear and only halve of what you see. Who said that?" I have a reply. Challenge everything. That is what thinking people do. Remember the earth is not as flat as some people think it is.

I have approached this with the desire to learn what makes a SB2 frame different than a SB1. So far the best I have heard is looks and "sound" when putting a barrel on.

I like it that people get upset when their opinions are challenged. As for me. Challenge away. There are alot of things I don't have the answers for. That is why I search for the truth. I want answers and not speculation. I dont want to regurgatate incorrect information. I am not looking to reinvent the wheel I am just looking for solid answers. Judging by the personal messages I am not the only one. Some are just afraid to post due to the brow beating they might get. Too bad.

quickdtoo · « **Reply #26 on:** December 10, 2006, 09:22:27 AM »

No need for anyone to be testy, we'll get some facts tomorrow, hopefully. This subject has come up before with some facts from our senior members, but those posts are as good as lost until Matt gets the search working again, he has to finish up the indexes before he'll turn it on again. After working on the forum for 20 some hours yesterday and this am, I'm sure he needs some rest. $:-\$

Tim

pills · « **Reply #27 on:** December 10, 2006, 09:37:33 AM »

Can I give you some questions I would like to ask Gordon? This way he is not answering the same questions all day.

1. What material differences are there in the SB1 & SB2?
1a. If there aren't any material differences what is done to make a SB2 stronger than a SB1?

2. What material differences are there between the SB1 and the old toppers?
2a. If there aren't any material differences, what prompted NEF to stop selling some of the barrels that once were included on the topper on the SB1?

3. Why does the 10 gauge need a special SB2 frame and a .410 work on a SB1 since the .410 is a higher pressure round?
(For that matter it seems the 10 gauge is the lowest pressure of all shotgun rounds.)

I am sure I will think of more later......

quickdtoo · « **Reply #28 on:** December 10, 2006, 09:47:23 AM »

Number 2 is easy, the H&R that made the orginal Topper went out of business in 1986, the current H&R 1871 LLC has no relationship to the old H&R and I'm pretty sure that's what Gordon will tell us.

Number 3 is also easy, the 10ga SB2 frame is much bigger in dimensions than the SB2 rifle frame, it's used on the 12ga Slug gun, also. Even if it has the same frame strength, no other rifle or shotgun barrel will fit it, stocks don't either from what's been posted before.

FWIW, Hubel458 has done some testing on the SB2 slug gun frame, he was impressed with it's strength, see his post in the shotgun forum on the 12ga from hell thread.

http://www.graybeardoutdoors.com/smf/index.php/topic,79991.msg574237.html#msg574237

Tim

http://hr1871.com/Support/faq.aspx

http://en.wikipedia.org/wiki/H_&_R_Firearms

http://www.chuckhawks.com/h-r_rifles.htm

http://oldguns.net/faq.htm#HR_Firearms

pills · « **Reply #29 on:** December 10, 2006, 09:53:16 AM »

In regards to #2, that doesnt really tell me what if any difference there is in material between the two.

In regards to #3, it may just be the way I am thinking, but I am wondering more of why it is an SB2 instead of SB1 or even a SB3 or some other designator.