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SMC
(Seattle Manufacturing Corporation)

Descent-Control Eight Mountaineering Eight
Descent-Control Eight Mountaineering Eight
 
Straight Eight, Version A Straight Eight, Version B Straight Eight, Version C
Straight Eight,
Version A
Straight Eight,
Version B
Straight Eight,
Version C

Overview


Descent-Control Eight
(#340)

Front Rear
Front Rear

Technical Details

I acquired my Descent-Control Eight from KHS Sales in 1992.

The SMC Descent-Control Eight is made from 9.4 mm. stainless steel rods bent to shape and then welded together. Mine is 126 mm tall, 90 mm. wide, and 10 mm. thick. The rope hole is 38 mm. high and 73 mm. wide. The top center thickness is 9 mm. The shaft length and width are 47 mm. and 30 mm., respectively. The eye measures 20 mm. by 29 mm. My eight weighs 215 g.

One side of the lower eye is stamped with the SMC logo, and the other with "PATENTED"

Comments

The SMC Descent-Control Eight is one of the few commercial welded steel rod figure eights. The rope hole is shorter and wider than normal, so it may provide too much friction on stiff or muddy ropes. I think that stiff ropes would run more smoothly if the rods were larger, but then the eight would be heavier. Even as it is, the SMC Descent-Control Eight is too heavy for my taste.


Mountaineering 8
(#1020)

Front Rear
Front Rear

Technical Details

I acquired my Mountaineering 8 from On Rope 1 in 2006.

The SMC Mountaineering 8 is milled from aluminum alloy plate and then hard anodized. Mine is 118 mm. tall, 75 mm wide, and 10 mm. thick. The rope hole is 40 mm. high and 50 mm wide. The top center thickness is 10 mm. The shaft length and width are 28 mm. and 25 mm., respectively. The eye measures 27 mm. by 21 mm. My eight weighs 81 g.

The front of this eight is stamped with the SMC logo and "5978."

 

The front of my Mountaineering 8 is engraved with the SMC logo and "5976."

Comments

The Mountaineering 8 is an example of a "Flat Top" aluminum eight. It is smaller than the Straight Eight and is lighter than most figure eights. The rope hole is shorter than normal, so it may provide too much friction on stiff or muddy ropes, but it is still quite usable on climbing ropes. The eye is too narrow to accept two full size locking carabiners.


Straight Eight, Version A
(#338, 975)

Front Rear
Front Rear

Technical Details

I do not have a record of where I acquired this eight, but it was probably in the late 1970s. I acquired a second one, used, from Harry Rogers in 2004.

The SMC Straight Eight, Version A is forged from aluminum alloy and then hard anodized. Mine is 125 mm. tall, 74 mm wide, and 17 mm. thick. The rope hole is 48 mm. high and 52 mm wide. The top center thickness is 12 mm. The shaft length and width are 36 mm. and 26 mm., respectively. The eye measures 19 mm. by 32 mm. My eight weighs 91 g.

Both sides of the shaft have "SMC" in raised letters.

Comments

The SMC Straight Eight, Version A is another example of a "Flat Top" aluminum eight. It is a compact eight, and is lighter than most figure eights.

I have a copy of the 1979 SMC catalog that lists this forged version of the straight eight. I do not know when SMC introduced it or when they replaced it with Version B.


Straight Eight, Version B
(#339, 2405)

Front Rear
Front Rear

Technical Details

I do not have a record of where I acquired this eight, but it was probably in the early 1980s. I acquired another in 2017 as part of Bob Thrun's collection.

The SMC Straight Eight, Version B is milled from aluminum alloy plate and then hard anodized. Mine is 126 mm. tall, 75 mm. wide, and 10 mm. thick. The rope hole is 48 mm high and 50 mm. wide. The top center thickness is 9 mm. The shaft length and width are 33 mm. and 26 mm., respectively. The eye measures 20 mm. by 32 mm. My eight weighs 95 g.

One side of the shaft is stamped with the SMC logo and "USA."

Comments

The SMC Straight Eight, Version A is another example of a "Flat Top" aluminum eight. The later version is milled from aluminum plate. I like milled eights more than forged ones (for no real valid reason), so this has been my normal caving eight for a number of years. Previously I used the Russ Anderson eights, but the straight eight is smaller and gives more friction - sometimes too much. One joke in my local caving club is "Help!! I'm Gary - and I can't get down!!" (Foreigners probably won't get the joke; it refers to an old late-night television commercial).

The anodizing is hard and wears well, but the radius of the rounded edges is greater than half the plate diameter, so there is a ridge where the two meet. This provides a wear concentrator, and rappelling on muddy ropes will soon lead to a breach at these points. The photo clearly shows how this occurs. Once breached, I would flip the eight over and wait for the other side to breach, and then retire the eight.

Front, After Step 3 Milling Rear, After Step 3 Milling
Front, After Step 3 Milling Rear, After Step 3 Milling

These photos show an complete mill blank taken after step 3 in manufacturing process. It shows that the first steps are to cut the blank, drill the holes, then mill the perimeter. Two more milling operations and the eight is ready to be anodized. I thank John Weinel for getting this for me.


Straight Eight, Version C
(#1374)

Front Rear
Front Rear

Technical Details

I acquired my SMC Straight Eight, Version C on eBay from Stanley E. Thomas in 2012.

The SMC Straight Eight, Version C is forged from aluminum alloy. Mine is 125 mm. tall, 75 mm. wide, and 10 mm. thick. The rope hole is 48 mm. high and 50 mm. wide. The top center thickness is 10 mm. The shaft length and width are 33 mm. and 25 mm., respectively. The eye measures 20 mm. by 32 mm. My eight weighs 92 g.

One side of the shaft is stamped with the SMC logo and "USA."

Comments

The SMC Straight Eight, Version C is another example of a "Flat Top" aluminum eight. This version is not anodized.