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Placing 3/8" Bolts, How Many Turns?

Original Post
Derek Barnes · · Ventura · Joined Aug 2014 · Points: 15

I am using 3/8" five piece Rawl Power bolts and am wondering if someone can give me a good rule of thumb regarding the max number of cranks or a rough description of how it should feel with a standard box wrench. I dont have a torque wrench and could not find info regarding turns on the Fixe or Powers web sites for 3/8". Muchas Gracias!

J. Albers · · Colorado · Joined Jul 2008 · Points: 1,926
John Wilder wrote:It's not number of turns (which will be different depending on the type of rock), it's torque and it's important. For a 3/8" stainless bolt, you'll want to use a small box wrench for tightening, and hold three fingers right up against the bolt side of the wrench and turn until its snug (not super tight)- that should be about 12lbs. You'll want to be very careful about over-tightening the 3/8" stainless bolt- they snap super easy, and if you over torque them, you are weakening them substantially.
I know that you have replaced a lot of bolts John, but seriously, do you really think your suggestion has any amount of accuracy? Probably not. How about Blommerz goes out and buys a torque wrench and does it right. Unless you are doing something ground up, I don't see any good reason not to carry a torque wrench (you're already carrying all sorts of other bolting gear so its not a big deal to toss in the wrench).
ABB · · Unknown Hometown · Joined Mar 2007 · Points: 0

Let's hope you're placing SS but in the case of 3/8" 5-piece carbon steel, the spec is 25 ft-lbs. Most would be surprised to learn just how 'light' 12 ft-lbs (for SS) feels, which explains the natural inclination to over-torque.

Can't help but feel a little concerned when someone asks, 'How many cranks?'. A good rule of thumb: use a torque wrench and do it right. Lives, for many years, depend on your fastidious handiwork.

J. Albers · · Colorado · Joined Jul 2008 · Points: 1,926
John Wilder wrote:Oh, I would much prefer that he go get a torque wrench, but I'm also realistic about the likelihood of some random off the internet buying a torque wrench because some random people told him to. As to the accuracy, I would argue that the method I suggest will get you somewhat close, which is better than cranking it down- it was shown to me by a guy who has placed way more bolts than most of us combined. That said, I use a torque wrench when I place mechanical bolts, and I always use 1/2" Stainless.
I hear you John, the guy who taught me to bolt (who like your guy, has placed a ridicules number of bolts) also uses both a short box and a torque wrench depending on the situation. But I really think that if someone asks, it is probably best to arm them with the idea of "best" practices, i.e. use SS, some LocTite, and a torque wrench. Anyway...
rocknice2 · · Montreal, QC · Joined Nov 2006 · Points: 3,847

12 ft/lbs is 25 pounds at the end of a 6" wrench.
Practice lifting a 25 pound weight with three fingers or pushing down on a bathroom scale.
Or buy a torque wrench.

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
rocknice2 wrote:12 ft/lbs is 25 pounds at the end of a 6" wrench.
Or 24lbs :-)
rocknice2 · · Montreal, QC · Joined Nov 2006 · Points: 3,847
Jim Titt wrote: Or 24lbs :-)
LOL yeah but not all three fingerrs for at the very end of the wrench.
Aric Datesman · · Unknown Hometown · Joined Sep 2008 · Points: 145

Only $22. Get one.

harborfreight.com/3-8-eight…

Bruce Hildenbrand · · Silicon Valley/Boulder · Joined Apr 2003 · Points: 3,615

Powers 3/8" 5-piece SS bolts come with a built in device which indicates proper torque. There is a little, grey plastic washer between the bolt head and the SS washer. Tighten the bolt until the grey, plastic washer deforms and is visible as it is squeezed out the side of the washer.

Locker · · Yucca Valley, CA · Joined Oct 2002 · Points: 2,349
"Muchas Gracias!"

Muchas n00bias is more like it.

How many turns?

Really?

YIKES!

"Yer GONNA die!!!"
David Gibbs · · Ottawa, ON · Joined Aug 2010 · Points: 2
Locker wrote:"Muchas Gracias!" Muchas n00bias is more like it. How many turns? Really? YIKES! "Yer GONNA die!!!"
Sadly, with an over-torqued bolt, it is probably someone else who is gonna die.
Scottmx426 · · Unknown Hometown · Joined Sep 2014 · Points: 0

Why not teach the novices to do it the right way with a torque wrench. I even have one id donate to make the public safe that's in the lower range. Leave the three finger touch for the wizards.

M Mobley · · Bar Harbor, ME · Joined Mar 2006 · Points: 911
Aric Datesman wrote:Only $22. Get one. harborfreight.com/3-8-eight…
I would be more inclined to start a n00b out with one of these-
sears.com/craftsman-3-8-in-…

the clickers are not easy to read/set properly and besides that I would never consider buying tools where accuracy may equate with life or death from China Freight Tools

this thread is funny and scary all at the same time
Greg D · · Here · Joined Apr 2006 · Points: 883

Yeah just do it by hand because you want 24 foot-pounds at 6 inches exactly from the center of the bolt so that means you need to be at 21 pounds at 7 inches exactly from the center of the bolt or 28 pounds exactly if you are 5 inches from the Super Bowl yes this is totally easy to do I am by a total inexperienced person this is freaking awesome I love it just one more reason why sport climbing is really scary.

Gunkiemike · · Unknown Hometown · Joined Jul 2009 · Points: 3,492

Look at the label on the Powers box. 3-5 turns:

mountainproject.com/v/power…

tom303 · · Colorado · Joined Aug 2011 · Points: 160
Fixe says 3 to 4 turns past finger tight. 12 ft*lb for 3/8", 25 ft*lb for 1/2"

This is the spec sheet from Fixe:
fixehardware.com/specs-manu…

12 ft*lb for 3/8"
25 ft*lb for 1/2"
Bruce Hildenbrand · · Silicon Valley/Boulder · Joined Apr 2003 · Points: 3,615

People must have missed reading this the first time around:-)

By Bruce Hildenbrand
Sep 19, 2014
Powers 3/8" 5-piece SS bolts come with a built in device which indicates proper torque. There is a little, grey plastic washer between the bolt head and the SS washer. Tighten the bolt until the grey, plastic washer deforms and is visible as it is squeezed out the side of the washer.

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346

I agree that the bolt should not be overtightened, and a torque wrench is the best way to ensure that happens. But I do not agree with John that they break easy, at last not the old RAWL 3/8" stainless ones.

I have probably removed about 100 3/8" SS RAWL 5-pieces, all about 10 years old and well corroded. I use a 1/2" x 16" driver to remove them, and I often find myself almost jumping on the end of the handle to try to turn the bolt since it's so corroded the bolt is nearly fused to the cone. I have even completely stalled out a 3/8" electric impact on the head for 20 seconds straight and not turned the bolt one bit, although I did completely strip the head off which later required me cutting the bolt off with a cutting disk.

While I have broken a number of them during removal, they dident break easily. They often required quite a bit of effort to break, often with so much effort that the driver flies off the head of the bolt and I bash my knuckles into the rock. Again, this is happening with a 16"-long driver which is much longer than most people use. I wouldn't be surprised if I am applying over 120 ft lbs before breaking the things.

Tim Stich · · Colorado Springs, Colorado · Joined Jan 2001 · Points: 1,520

Harbor Freight has a perfectly serviceable 3/8 inch torque wrench for $25. Get one. Not the 1/2 inch, sorry.

Look, tool weenies, for tightening bolts this is perfectly adequate quality. It beats guestimating when you have no idea.

M Mobley · · Bar Harbor, ME · Joined Mar 2006 · Points: 911

I'd rather climb runout choss on ballnuts than trust a China Freight torque wrench with my life, YMMV

TKeagle · · Eagle, CO · Joined Apr 2012 · Points: 79

Do everyone a favor and flip for a torque wrench. Until then you are probably under torquing on Rawls no matter how many knuckles you scrape with an open end wrench greasing off the head.

If you are taking the great responsibility to place bolts do it as best you can - people don't back bolts up generally and presume that you know what yer doing so don't be a douche!

Guideline #1: Don't be a jerk.

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