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DMM makes one or used to make one. I have one it is pretty cool does not wear like an aluminum device. Its pretty light too.
Dallen

bing.com/shopping/jul-belay…

Only for single rope though

The Larry wrote:Is there a company that makes one? I've heard rumors but have been unable to find any info.

There's a relatively unknown device out there called the grigri that is stainless where the rope runs through it;)

I have one of those DMM devices and I like it, though it has some issues with thicker ropes. That and a steel belay biner allowed me to stop wearing out gear every time I go to Utah, and my ropes stay cleaner. I'd like it if Black Diamond made a steel ATC, or Omega made a steel SBG, or Petzl made a steel Reverso, but so far none of them seem interested.

You could probably get a hold of a stainless steel sticht plate.

You might be looking for a DMM V-Twin if you can find anywhere that has them in stock still.

John Wilder wrote:Edelrid makes a few- a single rope tube called the Jul, and then they have two new ones coming out in early 2013- the Micro and Mega Jul. Both are locking assist tube devices. Can't really think of any others off the top of my head. I know DMM was working on one, but I dont think it has made it to the market yet.

How dare you use the word "locking"????

A rappel ring can work as a belay device in a pinch

Properly sized chain links work well too. Seriously.

storrick.cnc.net/VerticalDe…

Aric Datesman wrote:Properly sized chain links work well too. Seriously. storrick.cnc.net/VerticalDe…

Ah, chain links. I have never used one for belaying, but we use them all the time to make line lockers for slack and highlining. I have learned a lot about how those things can shred a piece of webbing. Interesting enough, when those are used as a line locker, the failure mode of the webbing is often by cutting of the chain link! The chain link actually pinches the webbing against the carabiner and cuts through it. But of course, none of that is relevant to roped climbing, just interesting IMO.

I used to ask myself the same thing awhile back. The main reason Aluminum is used for tube style devices is that Al has a higher coeffcient of friction and a better heat transfer coefficient. This means that Al will draw heat away from the rope faster and also provide more friction during a rappel.

Titanium is even worse than steel.

randy88fj62 wrote:I used to ask myself the same thing awhile back. The main reason Aluminum is used for tube style devices is that Al has a higher coeffcient of friction and a better heat transfer coefficient. This means that Al will draw heat away from the rope faster and also provide more friction during a rappel. Titanium is even worse than steel.

Actually, I am pretty confident Al is primarly used because it is lighter. That is why everything we use is made out of Al. If they are going for maximum heat dissipation they should look into making copper belay devices. :)

randy88fj62 wrote:I used to ask myself the same thing awhile back. The main reason Aluminum is used for tube style devices is that Al has a higher coeffcient of friction and a better heat transfer coefficient. This means that Al will draw heat away from the rope faster and also provide more friction during a rappel. Titanium is even worse than steel.

I have to disagree. The reason Al is used is because it's cheaper, lighter, and easier to manufacture with than steel.

The difference in coeff of friction on polished Al and polished steel will be negligible.

As far as heat, the rope is generating the heat and won't be touching the device in any one spot long enough to even get hot itself, (unless you stop obviously). I would argue that thermal capacity is more important (amount of energy it takes to raise the temperature of the metal) Steel is roughly half that of aluminum, so aluminum will heat up significantly slower than steel (with the same mass). Titanium is better than steel for heat capacity but close.

So besides the fact that aluminum wears out faster, its really the best material. A good device that was made of steel would cost a ton more than an aluminum one. You could just replace them more often and have less invested.

20 kN wrote: Actually, I am pretty confident Al is primarly used because it is lighter. That is why everything we use is made out of Al. If they are going for maximum heat dissipation they should look into making copper belay devices. :)

Silver beats out copper in terms of heat transfer, but neither is terribly strong and would result in a large, heavy, and expensive belay device.

Having done loads of research (also for DMM) on belay devices there isn´t much doubt aluminium is the best material available at the moment. You need a good heat transfer away from the rope contact point to keep glazing under control or worse if the abseiler stops prevent melting through the rope, you also want a higher specific heat capacity so that for a given amount of heat the temperature rises less. In particular stainless has such a poor heat transfer you can and will get problems with longer abseils. With a GriGri you can easily get temperatures well into the danger region and for this reason Petzl recommend less than 50m (or they used to).
Anodised aluminium has another advantage in that it radiates heat better and this is where the most cooling takes place, the convection cooling at the speed we abseil at being minimal (adding `cooling holes´ does virtually nothing and in some of the tests we ran actually makes things worse as the radiant area was reduced). Stainless steel is a very poor radiator of heat and you can easily measure this by heating both a stainless plate and an aluminium one to 100°C (boiling point of water) and measuring the temperature with both embedded probes and an IR thermometer, the Al plate shows about 94°C and the SS one around 60°C using an IR thermometer where in reality both are at 100°C.
There is also no measurable difference in the friction of nylon on any polished metal surface no matter the material.
Apart from longetivity there is no reason whatsoever to make a belay device from stainless steel and commercially no reason not to use aluminium since correctly designed aluminium plates have a proven lifetime of well over 30 years as owners of older Sticht plates know.

Jim Titt wrote:FACTS

Yeah, but.... Ummm... They won't corrode in a salt water environment?

;-)

AKMatt wrote:A good device that was made of steel would cost a ton more than an aluminum one. You could just replace them more often and have less invested.

I thought the same thing until I got my DMM steel device- it cost about what an ATC Guide did at the time I got it. And while Aluminium doesn't wear out real fast in "normal" situations, a sandy situation accelerates the wear quite a bit, so replacement comes often enough that a steel device costing twice what mine did would still pay for itself while also cutting down on that nasty rope gack.

after burning through loads of atc's I started using the SMC steel figure 8 for my canyoneering guiding program
while not great for climbing these things are tough. two full seasons of guiding and they show little wear
I have had no issues of overheating or rope glazing with them and we primarily are rapping single rope on 8-9mm cord.
I would love to see someone make a steel tube style belay device, I think there is a market for them, especially for people in the desert. trango.com/belay_rappel/smc…

Yeah they are spendy but I would reckon they last 10X as long as an atc. A lot up front but in the long run totally worth it. If you can get a pro deal or guiding deal they are about 35-40 a pop.

If you made something similar to the smc device with horns like the pirahana so you can more easily adjust friction and lock off you would nail the design imho.

I use them with the liberty mountain HMS steel locking carabiner which is virtually indestructible as well
this photo show both the 8 and carabiner. two years of heavy guiding use and very little wear

DMM didn´t find sales of stainless tube devices was worth it so I doubt anyone else will either, they are fairly hard to make!

Stainless 8 descenders are another matter since the cavers use them, ones with ears are available from Kong (Mini 8, Big 8) and PMI. They are available from karstsports.com/l435020.html
Easy to modify as well by a competent welder.

You get far less problems with 8´s overheating as they have more angular rope bend over larger radii whereas with tube-style belay plates the contact points for the rope are much smaller and tighter. They still twist the rope and and cavers use racks as this is eliminated and you can adjust the friction to suit the rope.