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What are these?


Original Post
Parker D · · BC · Joined May 2017 · Points: 60

Hey guys,

First and foremost, please excuse my lack of experience in bolting/drilling etc. I have done tremendous amounts of research on the topic and its disciplines but am still nowhere near where I want to be, which is why I have come to you, for your help. 

So the good stuff - Found a big ol stock of these bolts at an adventure park company I work with, and can't seem to ID them. I have done several searches using the markings I can find on these bolts combined with my little knowledge but can't seem to find anything. They're 4 piece bolts and the only markings I can find on them are a "4.8" on the bolt head, and "YQ  M12" on the outer shaft. I have attached pictures of them, including pics of both the markings I can find on them.

Does anybody know what these guys are?? Are these usable for any climbing purposes etc?

Thanks!

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,348

M12 means it's metric 12mm so you'd need a 12mm SDS bit to place them. The 4.8 mean it's class 4.8 steel which is low carbon mild steel. It's pretty weak as far as steel goes, even weaker than unlabeled grade 2 bolts at Home Depot. Class 4.8 is only about 61,000 PSI UTS by specification. By contrast grade 2 is 74,000 PSI and grade 5 is 120,000 PSI.

Without pull testing them or knowing the manufacturer's minimum strengths table, I wouldent use them for climbing, not if they are made of steel weaker than grade 2. Also, they are carbon steel so they are not suitable for many outdoor locations. I'd try to find some quality stainless steel bolts instead, especially if you're from BC where it rains a crap-ton.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 451
20 kN wrote:

... especially if you're from BC where it rains a crap-ton.

Ah, can you be more specific?  Is that more than a shit-load?  ;-)

JFM · · Unknown Hometown · Joined Jul 2010 · Points: 1,828

^^ also it depends if we're talking about metric class 4.8 shit tons vs imperial grade 3 shit loads...

Robert Cort · · Unknown Hometown · Joined Oct 2009 · Points: 800

It's a metric bolt.  4.8 indicates the approximate tensile strength in MPa and approximate yield strength as a percentage of 1,000MPa.  So in this case, tensile strength = 4,000MPa, and yield strength = 800MPa.

M12 indicates metric, 12mm thread diameter (coarse thread pitch unless otherwise indicated)

I think the Yq indicates 1.5 factor of safety for design loads (not sure on this one). 

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,348
Robert Cort wrote:

It's a metric bolt.  4.8 indicates the approximate tensile strength in MPa and approximate yield strength as a percentage of 1,000MPa.  So in this case, tensile strength = 4,000MPa, and yield strength = 800MPa.


The 4.8 stamp means it's a class 4.8 bolt which means it's 420 MPa. There are no 4,000 MPa masonry anchors. That would be as strong as tool steel which would be both extremely expensive and completely ridiculous for use in masonry. Even SAE grade 8 bolts are "only" 1000 MPa.
https://en.wikipedia.org/wiki/ASTM_F568M

Parker D · · BC · Joined May 2017 · Points: 60

Wow, definitely learned a lot here, thanks so much guys! 

And yes, BC does refer to British Columbia, land of the squamtown which, by the way, was soaking wet last week in mid July.. 

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,348
John Byrnes wrote:

Ah, can you be more specific?  Is that more than a shit-load?  ;-)

It's metric. About the same though.

Billcoe · · Unknown Hometown · Joined Mar 2006 · Points: 655
Parker D wrote:

Hey guys,

First and foremost, please excuse my lack of experience in bolting/drilling etc. I have done tremendous amounts of research on the topic and its disciplines but am still nowhere near where I want to be, which is why I have come to you, for your help. 

So the good stuff - Found a big ol stock of these bolts at an adventure park company I work with, and can't seem to ID them. I have done several searches using the markings I can find on these bolts combined with my little knowledge but can't seem to find anything. They're 4 piece bolts and the only markings I can find on them are a "4.8" on the bolt head, and "YQ  M12" on the outer shaft. I have attached pictures of them, including pics of both the markings I can find on them.

Does anybody know what these guys are?? Are these usable for any climbing purposes etc?

Thanks!

Hey Parker, good on you for researching it first. I'll stick my main point in first so to minimize eyeglazing which is so common when an old fuck like me starts rambling. Google this: "ICC rated anchors". Think of ICC (formerly ICBO) as similar to a UL rating for an electrical device. No one building anything larger than a dog house would dare to use any non-ICC rated anchor. You'd be sued into hell and also have personal liability if a structure failed and folks died. As climbers, I advocate always using anchors that are ICC rated. All of the major US mfg of anchors rate their anchors to ICC. Red Head, Hilti, Powers, Simpson etc. No construction company building a structure would ever use non-rated anchors: ever. 

That's not to say that your weak assed SLEEVE anchor rated to 4.8 (which is a metric strength rating for the bolt in the Sleeve anchor) wouldn't hold a fall or work fine in many climbing applications. But it would be irresponsible to use such a weak thing in my view without knowing the manufacturer and strength rating. One generic M12 metric 4.8 sleeve anchor I pulled up gives a suggested 1166 lb max shear rating (which may be a significantly reduced number from ultimate shear -they didn't spell that out). As a toprope fall can generate 1300 lbs (going from memory, per some climbing mag test years back), that would be something to be damned cautious about. You need to know several things with 100% assurance and you won't get them fishing stuff out of a bin. If you look up the strengh ratings on 3/8" (smaller than your M12) and 1/2" wedge anchors you'll see the ultimate shear @ 4000 lbs and up which may be comp. to what you have, who knows for sure. Mostly you want to know for sure that the anchors you use are ICC rated. 

Anyway, if we were talkin and drinkin, this would go on much longer and in depth discussing rock type, drill size, suggested torque etc etc etc etc, but as I'm at work and typing, that's the short version -just avoid using them. Buy an ICC rated stainless wedge anchor or go with glue ins instead.   

Guideline #1: Don't be a jerk.

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