Gear Review: Metolius Astro Nut ‘Aid’ - A Micro Miss?

Brand: Metolius
Model: Astro Nut ‘Aid’ (1-5)
Class: Micro, Flared

Metolius Astro Nuts come into two sets, Aid (1-5) and Free (6-10); ten nuts to cover the micro range covered by other brands cover in only six or seven nuts. Aid and Free sets have very different shapes, and cables. The Free set is great, but this is a review of the Aid set which, as one might guess, is used exclusively for aid.

The Astro ‘Aid’ is well made, but likely too niche for most racks, even bold aid climbers.

Metolius Astro Nuts (1-5)

Specs

The Astro Nut ‘Aid’ (1-5), is made of a silicone bronze alloy and soldered to its cable. Strength ratings are (1, 2) 1.4k, (3, 4, 5) 2.5kn. It is slightly flared along the broad axis and near parallel along the short axis. The vertical axis has a straight taper. Its surfaces are flat, if not just faintly rounded. The set weighs 32g.

The very slight angles of the Metolius Astro Nuts (1-5).

Wishing the scary thin cables were more substantial on the larger nuts.

The rating 2kn on sizes 1 and 2 (pictured top), differ from the Metolius website which lists 1.4kn on the smaller two sizes.

Performance

Astro features a silicone bronze, more durable than brass and stickier than aluminum. This sweet spot alloy is great, but very comparable to the alloy of other micro nuts. The broad axis flare of the Astro is subtle and almost absent on the smallest two pieces. The lack of a strong or even moderate flare means it is not a good fit for pin scars. The Astro densely covers a tiny range of placements that serve an infrequent need. Other brands, perhaps wisely, only make 3 sizes to cover this range. To clarify: Astro’s 1-5 size range is near equivalent to DMM’s 0, 1 and 2 Brass Offsets or Black Diamond’s 1, 2 and 3 Micros. Astro Nut Aid strength rating is ‘aid-only’ across the entire set, with no practical wiggle room—falls or mistaken bounce testing will break the wire. This is a shortcoming compared to the rest of the market. DMM Brass Offsets, for instance, are rated 2kn for the size 0, but manage thicker cables with a 4kn rating on the number 1 and 5kn for the number 2.

Left to right: Metolius 4 (2.5kn), 5 (2.5kn), DMM 2 (5kn), 1 (4kn)

DMM Brass Offets (0-2) top; Metolius Astro (1-5) bottom

The Astro Aid (1-5) is fine, but very few climbers will bother. It just misses too many opportunities to be better and here are lots of good options out there. Snag the DMM Brass Offsets and if you must, supplement them with the Black Diamond Micro Stoppers for a better stronger solution to ultra-thin nuts.