SCRAP MY LAST ANSWER! I very carefully got it the wrong way round!

There is a choice of techniques depending on the circumstances and the material you have to hand. Tapes (flat & tubular webbing) are used to make various sorts of slings, harnesses or whatever… when it has been made into a “sangle” then it is being used as a “strap” of some sort. I think you can translate literally here as what it has been made into will determine its full technical name and as your original is not specific….

If you are determined to use a slightly more technical sounding term, then how about “sling” (GB) which in the US is a “runner”?

("Runner" to a UK climber is what a US climber would refer to as a "running belay")!

1 - http://home.tiscalinet.de/ockier/climbing_dict.html
sling = what the Americans call a “runner”.
Runner (1) = a loop of tape or webbing either sewn or tied (Aka sling, especially in the UK). In the UK, a 'runner' is a running belay. (d) Schlinge, (f) Sangle, (i) Anello, (e) Anilla, (s) Slinga, (pl) Talma ?, (pl) Petla

http://www.wildcountry.co.uk/
We design our slings with the same care we give to all our equipment, selecting the very best webbing and then applying the most appropriate CNC controlled stitch patterns to maximise the strength of each sling.

This year we are introducing a new 12mm Dyneema® webbing. This specification is exclusive to Wild Country and produces extremely light and compact slings.
Runner
http://www.clubalpin.be/lesguides/technic/fiche2/fiche2.htm
Cette technique permet d'aller vite et de se partager le travail (pardon, le plaisir de grimper en types de relais que tu peux trouver
Top page
· · - Un relais idéal est constitué de deux points d'encrage reliés entre eux par un élément solide (chaîne, corde ou sangle d'escalade).
- En Belgique malheureusement, nos relais sont souvent fait de un seul gros anneau (voir une plaquette) au sommet de la voie (ex : D'Ave)

http://www.meq.gouv.qc.ca/ens-sup/ens-coll/Cahiers/cours-com...
Techniques d'assurage : du haut de la paroi, du bas de la paroi, auto- assurance. Techniques d'escalade libre. Techniques de descente. Techniques d'utilisation de coins i.e. hexagon, hexentrique, stopper, coin de bois, bong, copperhead, titon, etc. Techniques d'utilisation d'anneaux, de cordelettes et de sangle. Premiers soins propres à l'escalade. Évacuation et transport d'une victime ou d'un blessé

http://www.gearngo.com/climbing/Strap_Kit_with_Side_Adjuster...
Climbing & Mountaineering: Strap Kit with Side Adjusters
Climbing & Mountaineering: Strap Kit with Side Adjusters So
Further on-line sources for climbing vocab.
GLOSSARIES
http://climb.mountainzone.com/glossary_a_l.html
http://climbing.about.com/recreation/climbing/library/gloss/...
http://www.gorp.com/gorp/activity/climb/clim_gloss2
http://www.terraquest.com/highsights/bigwall/glossary.html

EQUIPMENT SUPPLIERS
http://www.mec.ca/Main/home.jsp
http://www.wildcountry.co.uk/