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Rock Empire Brass Chocks

Original Post
Seth Jones · · New Lenox, IL · Joined Feb 2015 · Points: 25

Anyone have experience with these? How would they compare to DMM IMPs aside from having the wire loop around instead of being soldered in place? I'm wondering if they cover a comparable size range but it looks like they are probably wider and more like a standard stopper, just in brass.…-

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

I don´t have a set of IMPs to compare but here´s the sizes for the Rock Empire ones:-

Size: 1 / 2 / 3 / 4 / 5 / 6 / 7 /
Strenght (kN):6 - 9 kN
Range (mm):5-9 / 6-10 / 7-11 / 8-12 / 8,8-13 / 9,5-13,8 / 11,8-14,8 / 13,8-15,5 mm
Weight (g): 17 / 18 / 19 / 26 / 28 / 30 / 34 / 38 g

Seth Jones · · New Lenox, IL · Joined Feb 2015 · Points: 25

Yeah I found the size chart but couldn't find one for the IMPs and it doesn't list the width. I'm assuming they are the dimensions of a normal stopper.

anotherclimber · · Unknown Hometown · Joined Apr 2016 · Points: 70


I don't have any personal experience with these stoppers. I'm just presenting some data for you and giving you my own opinion so you can come to your own conclusion of whether these would work for you.

The sizing for the DMM I.M.Ps is listed in the user manual:…

DMM IMPs size and strength.

What doesn't list the width? My understanding of nut/stopper sizing is that the two numbers specify length and width. Between Jim Titt's post of the sizing for the Rock Empire set and this post of the DMM I.M.P. set that should give you the information you need.

I'm actually surprised they opted to swage these brass nuts versus silver solder them since we know that a larger and thusly stronger wire can be soldered onto a micro nut. This does though increase the cost.

Comparing them in size to standard size nut sets:

DMM Wallnut - size and strength.

Black Diamond Stopper Set - strength and size:

Strength :
[size 1-2] 2 kN (450 lbf)
[size 3] 5 kN (1124 lbf)
[size 4-5] 6 kN (1349 lbf)
[size 6-12] 10 kN (2248 lbf)
Dimensions :
[size 1] 4.3/9.1 mm (0.17/0.36 in)
[size 2] 4.8/9.9 mm (0.19/0.39 in)
[size 3] 6.1/11.4 mm (0.24/0.45 in)
[size 4] 6.9/12.4 mm (0.27/0.49 in)
[size 5] 8.4/13.5 mm (0.33/0.53 in)
[size 6] 10.2/15.5 mm (0.40/0.61 in)
[size 7] 11.7/16.3 mm (0.46/0.64 in)
[size 8] 13.5/18.3 mm (0.53/0.72 in)
[size 9] 15.2/20.8 mm (0.60/0.82 in)
[size 10] 17.3/23.4 mm (0.68/0.92 in)
[size 11] 20.1/26.7 mm (0.79/1.05 in)
[size 12] 22.9/30.5 mm (0.90/1.20 in)
[size 13] 26.4/35.1 mm (1.04/1.38 in)

The smallest size of the Rock Empire Brass Chock Set is approximately the size of a Black Diamond #2 Stopper rated at 2kN and sized at 4.8/9.9 mm which is definitely an aid rated piece. For DMM Wallnuts it puts them one or two sizes below the #1 rated at 7/4kN and sized 6.7/14.3mm depending on how you look at it.

It's been my observation that any micro nut set usually overlap somewhat into the smallest sizes of a standard nut set. By how much it does so will depend on what you already have and what micro nuts you are looking at. Notice the range chart which I've conveniently turned the correct way for Rock Empires passive protection comparison:

Rock Empire passive protection range comparison.

The Rock Empire Brass Chock set seem to be pretty strong for the sizes compared to other swaged nuts. What concerns me though is the the three smallest sizes are not rated for being placed and protecting a fall in their sideways position listed as "strength B" in the picture below.

Rock Empire Brass Chock Set - strength and weight.

The DMM I.M.Ps don't have this problem. You can place them either way and get the same protection rating. If that limitation is ok with you and you can remember not to place the three smallest sizes in their sideways position then perhaps they will work for you. Otherwise the DMM I.M.Ps offer smaller protection sizes in different increments at a bit more than double the cost of what you can get the Brass Chock Set off of Ebay here in the USA.
slim · · Unknown Hometown · Joined Dec 2004 · Points: 1,088

i don't have the RE brass, but I do have some old trango brass that are swaged. i think they are very similar, if not the same. from the photos they look totally the same.

i also have the IMP's. they would be hard to compare. for the most part the trangos are quite a bit larger. the IMP's cover a significantly smaller size range.

also, the IMP's are easier to place when you start getting down into that small of a range. they fit in shallower placements. the loop of the cable at the head of the trango stopper can also get in the way in tight placements.

if it were me, i would fork out the extra $$$ for the IMP's. they are excellent.

the schmuck · · Albuquerque, NM · Joined Feb 2012 · Points: 110

Slim, you are correct. Trango used to be the distributor for RE, and would put their label on RE products. They did this with several Czech manufacturers in the 90s.

Seth Jones · · New Lenox, IL · Joined Feb 2015 · Points: 25

Thanks guys. I'm gonna pass on them for now. I might consider some in the future but not as a substitute for IMPs.

Guideline #1: Don't be a jerk.

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